SimXpert R3.2 Crash Workspace Guide
January 8, 2017 | Author: paulkastle | Category: N/A
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Introduction 1
Crash Workspace Guide Introduction
2 Overview and Definition
Overview and Definition An overview of the SimXpert crash workspace is given here.
Introduction SimXpert crash is a preprocessor for graphically preparing input data for LS-DYNA, an explicit dynamic software, used in applications such as crash, crush, and drop test simulations. Use of crash workspace allows users to work within one common modeling environment with other SimXpert workspaces such as Structures. Thus, for example, a model originally prepared for NVH, linear, or implicit nonlinear analysis can be easily used in explicit applications (crash). This dramatically reduces the time spent to build different models for implicit and explicit analysis and prevents you from making mistakes because of unfamiliarity between different programs.
Theory A detailed theory of explicit analysis is outside the scope of this guide. However, it is important to understand the basics of the solution technique, since it is critical to many aspects of using the SimXpert crash workspace. If you are already familiar with explicit methods and how they differ from implicit methods, you may disregard this section.
Method of Solution Although crash simulation software, including LS-DYNA uses the Explicit methods, a brief overview of both the Implicit and the Explicit Methods for the solution of dynamic response calculations is given below. Implicit Methods Most finite element programs use implicit methods to carry out a transient solution. Normally, they use Newmark schemes to integrate in time. If the current time step is step acceleration at the end of step
n + 1 will satisfy the following equation of motion: ext
Ma' n + 1 + Cv' n + 1 + Kd' n + 1 = F n + 1 where:
M C K ext Fn + 1
n , a good estimate of the
=
mass matrix of the structure
=
damping matrix of the structure
=
stiffness matrix of the structure
=
vector of externally applied loads at step
n+1
Introduction 3 Overview and Definition
a' n + 1 v' n + 1 d' n + 1
n+1 = estimate of velocity at step n + 1 = estimate of displacement at step n + 1 =
estimate of acceleration at step
and the prime denotes an estimated value. The estimates of displacement and velocity are given by: 2
d'n + 1 = d n + v n Δt + ( ( 1 – 2β )a n Δt ) ⁄ 2 + βa'n + 1 Δt
2
v' n + 1 = v n + ( 1 – γ )a n Δt + γa'n + 1 Δt or
d'n + 1 = d *n + βa'n + 1 Δt
2
v' n + 1 = v n* + γa'n + 1 Δt where
Δt is the time step, and β , and γ are constants.
The terms
d n* and v n* are predictive and are based on values already calculated.
Substituting these values in the equation of motion results in 2
ext
Ma' n + 1 + C ( v* n + γa' n + 1 Δt ) + K ( d* n + βa' n + 1 Δt ) = F n + 1 or 2
ext
[ M + CγΔt + KβΔt ]a' n + 1 = F n + 1 – Cv n* – Kd n* The equation of motion may then be defined as residual
M*a'n + 1 = F n + 1
The accelerations are obtained by inverting the –1
M* matrix as follows:
residual
a'n + 1 = M* F n + 1
This is analogous to decomposing the stiffness matrix in a linear static analysis. However, in dynamics, mass and damping terms are also present.
4 Overview and Definition
Explicit Methods The equation of motion ext
Ma n + Cv n + Kd n = F n can be rewritten as ext
int
Ma n = F n – F n –1
residual
an = M Fn where:
ext
=
vector of externally applied loads
=
vector of internal loads (e.g., forces generated by the elements and hourglass forces)
=
Cv n + Kd n
=
mass matrix
Fn
int
Fn M
The acceleration can be found by inverting the mass matrix and multiplying it by the residual load vector. In LS_DYNA, like any explicit finite element code, the mass matrix is lumped which results in a diagonal mass matrix. Since M is diagonal, its inversion is trivial, and the matrix equation is a set of independent equations for each degree of freedom, as follows: residual
a ni = F ni
⁄ Mi
The Leap-frog scheme is used to advance in time. The position, forces, and accelerations are defined at time level n , while the velocities are defined at time level
n + 1 ⁄ 2 . Graphically, this can be depicted as:
v n + 1 ⁄ 2 = v n – 1 ⁄ 2 + a n ( Δt n + 1 ⁄ 2 + Δt n – 1 ⁄ 2 ) ⁄ 2 d n + 1 = dn + v n + 1 ⁄ 2 Δt n + 1 ⁄ 2
Introduction 5 Overview and Definition
n–1 d, F, a
n–1§2 v
n d, F , a
n+1§2
v
n+1 d, F , a
time
The Leap-frog scheme results in a central difference approximation for the acceleration, and is secondorder accurate in
Δt .
Explicit methods with a lumped mass matrix do not require matrix decompositions or matrix solutions. Instead, the loop is carried out for each time step as shown in the following diagram: Grid-Point Accelerations Leap-frog Integration in Time Grid-Point Velocities
Grid-Point Displacements
Element Formulation and Gradient Operator Element Stain Rates Constitutive Model and Integration Element Stresses Element Formulation and Divergence Operator Element Forces at Grid-Points CONTACT, Fluid-Structure Interaction, Force/Pressure boundaries + External Forces at Grid Points
Explicit Time Step Implicit methods can be made unconditionally stable regardless of the size of the time step. However, for explicit codes to remain stable, the time step must subdivide the shortest natural period in the mesh. This means that the time step must be less than the time taken for a stress wave to cross the smallest element in the mesh. Typically, explicit time steps are 100 to 1000 times smaller than those used with implicit codes. However, since each iteration does not involve the costly formulation and decomposition of matrices, explicit techniques are very competitive with implicit methods. Because the smallest element in an explicit solution determines the time step, it is extremely important to avoid very small elements in the mesh.
6 Overview and Definition
Courant Criterion Since it is impossible to do a complete eigenvalue analysis every cycle to calculate the timestep, an approximate method, known as the Courant Criterion, is used. This is based on the minimum time which is required for a stress wave to cross each element:
Δt = SL/c where:
Δt S L c
=
Timestep
=
Timestep scale factor ( 0) for which this erosion definition applies.
EXCL
The Exclusion number. When any of the failure constants are set to the exclusion number, the associated failure criteria calculations are bypassed. For example, to prevent a material from going into tension, you may specify an unusual value for the exclusion number, e.g. 1234., set Pmin to 0.0 and all the remaining constants to 1234. The default value is 0.0, which eliminates all criteria from consideration that have their constants set to 0.0, or left blank.
PFAIL
Pressure at failure, Pmin. Failure occurs when pressure is less than PFAIL
Materials 15 Materials
Field
Comments
SIGP1
principal stress at failure, σmax. Failure occurs when the maximum principal stress exceeds SIGP1.
SIGVM
Equivalent stress at failure, σvM. Failure occurs when the von Mises equivalent stress exceeds SIGVM.
EPSP1
Principal strain at failure, εmax. Failure occurs when the maximum principal strain exceeds EPSP1.
EPSSH
Shear strain at failure, γmax. Failure occurs when the maximum shear strain exceeds EPSSH.
SIGTH
Threshold stress, σ0 (used in evaluating the Tuler-Butcher criterion)
IMPULSE
Stress impulse for failure, Kf. Failure occurs when the Tuler-Butcher criterion exceeds IMPULSE.
FAILTM
Failure time. When the analysis time exceeds the failure time, the material is removed.
Remarks: 1. This failure model only applies to the 2D and 3D solid elements with one point integration. See Also: • LS-DYNA Keyword User’s Manual MAT_ANISOTROPIC_ELASTIC This material model is used for modeling elastic anisotropic behavior of solids.
Field
Contents
Title
Unique name identifying the material model.
Desc
Optional description of the material model.
16 Materials
Field
Contents
TITLE_OPTION
If selected, the material Title will be exported to LS-DYNA
MID
Material identification number. (Integer > 0)
RO
Mass density.
C11... C66
Anisotropic constitutive matrix components
AOPT
Material axes option
XP, YP, ZP
Coordinates for point P (for AOPT= 1 and 4)
A1, A2, A3
Components of a vector a (for AOPT=2)
D1, D2, D3
Components of a vector d (for AOPT=2)
V1, V2, V3
Components of a vector v (for AOPT= 3 and 4)
BETA
Material angle in degrees (for AOPT= 3)
REF
Use Reference geometry to initialize the stress tensor
See Also: • LS-DYNA Keyword User’s Manual MAT_BLATZ-KO_RUBBER This is used to model nearly incompressible continuum rubber. The Poisson’s ratio is fixed to 0.463
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear modulus
REF
Use reference geometry to initialize the stress tensor (0 =off; 1 = on)
See Also: • LS-DYNA Keyword User’s Manual
Materials 17 Materials
MAT_CABLE_DISCRETE_BEAM This material model is used to define elastic cables realistically.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass density
E
Young’s modulus (if value greater than zero), or stiffness (if value smaller than zero)
LCID
Load curve Id for loading (engineering stress vs. engineering strain)
F0
Initial Tensile Force
TMAXF0
Time for which pre-tension force will be held
TRAMP
Ramp-up time for pre-tension force
IREAD
Flag: If value greater than zero, use the value of OUTPUT from card 2.
OUTPUT
Flag = 1 to output axial strain
Remarks: 1. The force, F generated by the cable is nonzero if the cable is in tension. The force is given by: F = max (F0 + KΔL, 0.) where K is the stiffness, and ΔL is the change in length. If E is greater than zero, K is defined as: K = (E X cross sectional area)/ (Initial length - offset) 2. A constant force element can be obtained by setting: F0 > 0, and K = 0
18 Materials
3. The cross section, and offset are defined on the *SECTION or *ELEMENT cards. For a slack cable, the offset should be input as a negative value. For an initial tensile force, the offset should be positive. 4. If a load curve is specified, the Young’s modulus will be ignored, and the load curve will be used instead. The points on the load curve are defined as engineering stress vs. engineering strain. The unloading behavior follows the loading. See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC This LS-DYNA material model (001) is an isotropic elastic material available for beam, shell and solid elements.
Field
Contents
Title
Unique name identifying the material model.
Desc
Optional description of the material model.
TITLE_OPTION
If selected, the material Title will be exported to LS-DYNA
MID
Material identification number. (Integer > 0)
RO
Mass density.
E
Young’s modulus
PR
Poisson’s ratio
DA
Axial damping factor (used in Belytscho-Schwer beam type 2 only)
DB
Bending damping factor (used in Belytscho-Schwer beam type 2 only)
Remarks: 1. The axial and bending damping factors are used to damp down numerical noise. The update of the force resultants, F i , and moment resultants, M i , includes the damping factors:
Materials 19 Materials
n+1
Fi
n+1
Mi
n DA n+1⁄2 = F i + 1 + -------- ΔF i Δt
DB n n+1⁄2 = M i + 1 + -------- ΔM i Δt
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_FLUID This LS-DYNA material model (001) is an isotropic elastic material available for solid elements.
Field
Contents
Title
Unique name identifying the material model.
Desc
Optional description of the material model.
TITLE_OPTION
If selected, the material Title will be exported to LS-DYNA
MID
Material identification number. (Integer > 0)
RO
Mass density.
E
Young’s modulus
PR
Poisson’s ratio
DA
Axial damping factor (used in Belytscho-Schwer beam type 2 only)
DB
Bending damping factor (used in Belytscho-Schwer beam type 2 only)
K
Bulk Modulus (for fluid option)
VC
Tensor viscosity coefficient (between 0.1 and 0.5)
CP
Cavitation pressure (default = 1.0E+20)
20 Materials
Remarks: 1. The axial and bending damping factors are used to damp down numerical noise. The update of the force resultants, F i , and moment resultants, M i , includes the damping factors: n+1
n DA n+1⁄2 = F i + 1 + -------- ΔF i Δt
n+1
DB n n+1⁄2 = M i + 1 + -------- ΔM i Δt
Fi
Mi
2. Fluid like behavior is obtained with the following relationship between bulk modulus, K, and pressure rate, p:
E K = -----------------------3 ( 1 – 2υ ) ·· p = – Kε ii A tensor viscosity VC, if used, which acts only on the deviatoric stresses See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_PLASTIC_THERMAL Temperature dependent material coefficients can be defined using this material type. A minimum of two temperature points are needed, and a maximum of eight can be defined.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
Materials 21 Materials
Field
Comments
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
YM_LC
Load curve defining Young’s modulus Vs. Temperatures.
PR_LC
Load curve defining Poisson’s raito Vs. Temperatures.
A_LC
Load curve defining the coefficent of thermal expansion Vs. Temperatures.
SIGY_LC
Load curve defining Yield stressVs. Temperatures.
V_LC
Load curve defining the plastic hardening modulus Vs. Temperatures.
See Also: • LS-DYNA Keyword User’s Manual MAT_ISOTROPIC_ELASTIC_PLASTIC Defines an isotropic plasticity material with isotropic hardening. This is a very low cost plasticity model, suitable for 3D solids and plane stress elements. If used in shell elements, this material model leads to inaccurate shell thickness updates and stresses after yielding.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
RO
Mass density.
G
Shear modulus.
SIGY
Yield Stress.
ETAN
Plastic hardening modulus
BULK
Bulk modulus
22 Materials
Remarks: 1. In the plane stress implementation for shell elements, a one-step radial return approach is used to scale the Cauchy stress tensor if the state of stress exceeds the yield surface. See Also: • LS-DYNA Keyword User’s Manual MAT_LOW_DENSITY_FOAM This material is used to model highly compressible low density foams. Its main applications are for seat cushions and padding on the Side Impact Dummies (SID). Optionally, a tension cut-off failure can be defined.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
RO
Mass density.
E
Young’s modulus
LCID
Load Curve Id for nominal stress versus strain
TC
Tension cut-off stress
HU
Hysteric unloading factor (between 0 and 1). Default is 1 (no energy dissipation)
BETA
Decay constant (β) for creep in unloading
Materials 23 Materials
Field DAMP
Contents Viscous damping coefficient (0.05< recommended value < 0.50) to model damping effects. LT. 0: the absolute value of DAMP is used as the load curve which defines the damping coefficient as a function of the maximum strain in compression εmax (see Remark 1). In tension, the damping constant is set to the value corresponding to the strain at 0.
SHAPE
Shape factor for unloading. Active for non-zero values of the Hysteric unloading factor (HU)
FAIL
Failure option, after cut-off stress reached. = 0, Tensile stress remains at cut-off value = 1, Tensile stress is reset to zero
BVFLAG
Bulk viscosity activation flag = 0, No bulk viscosity (recommended, default) = 1, Bulk viscosity active
ED
Young’s relaxation modulus Ed (optional), for rate effects.
BETA1
Optional Decay constant β1
KCON
Stiffness coefficient for contact interface stiffness. If undefined, the maximum slope in the stress vs. strain curve is used.
REF
Use Reference geometry to initialize the stress tensor. The reference geometry is defined by the keyword: *INITIAL_FOAM_REFERENCE_GEOMETRY. = 0, Off = 1, On
Remarks: The compressive behavior is illustrated in Figure 1 where hysteresis on unloading is shown. This behavior under uniaxial loading is assumed not to significantly couple in the transverse directions. In tension the material behaves in a linear fashion until tearing occurs. Although the implementation may be somewhat unusual, it was motivated by Storakers (1986). The model uses tabulated input data for the loading curve where the nominal stresses are defined as a function of the elongations, εi , which are defined in terms of the principal stretches, λ i , as:
εi = λi – 1
24 Materials
The stretch ratios are found by solving for the eigenvalues of the left stretch tensor, V ij , which is obtained via a polar decomposition of the deformation gradient matrix, F ij . Recall that,
F ij = R ik Ukj = V ik Rkj The update of Vij follows the numerically stable approach of (Taylor and Flanagan 1989). After solving for the principal stretches, we compute the elongations and, if the elongations are compressive, the corresponding values of the nominal stresses, τi are interpolated. If the elongations are tensile, the nominal stresses are given by
τ i = Eε i and the Cauchy stresses in the principal system become
τi σ i = ---------λ i λk The stresses can now be transformed back into the global system for the nodal force calculations. Additional Remarks: 1. When hysteretic unloading is used the reloading will follow the unloading curve if the decay constant, β , is set to zero. If β is nonzero the decay to the original loading curve is governed by the expression:
1. – e
– βt
2. The bulk viscosity, which generates a rate dependent pressure, may cause an unexpected volumetric response and, consequently, it is optional with this model. 3. The hysteretic unloading factor results in the unloading curve to lie beneath the loading curve as shown below. This unloading provide energy dissipation which is reasonable in certain kinds of foam. 4. Note that since this material has no effective plastic strain, the internal energy per initial volume is written into the output databases. 5. Rate effects are accounted for through linear viscoelasticity by a convolution integral of the form r
σ ij =
∂ε kl --------- dτ g ( t – τ ) 0 ijkl ∂τ t
where g ijkl ( t – τ ) is the relaxation function. The stress tensor augments the stresses determined from the foam. Consequently, the final stress, σ ij is taken as the summation of the two contributions: f
r
σ ij = σ ij + σ ij
Materials 25 Materials
Since we wish to include only simple rate effects, the relaxation function is represented by one term from the Prony series: N
g ( t ) = α0 +
am e
– βt
m=1
given by,
g ( t ) = Ed e
–β1 t
This model is effectively a Maxwell fluid which consists of a damper and spring in series. We characterize this in the input by a Young's modulus, Ed , and decay constant, β 1 .The formulation is performed in the local system of principal stretches where only the principal values of stress are computed and triaxial coupling is avoided. Consequently, the one-dimensional nature of this foam material is unaffected by this addition of rate effects. The addition of rate effects necessitates twelve additional history variables per integration point. The cost and memory overhead of this model comes primarily from the need to “remember” the local system of principal stretches.
Figure 1
Behavior of the Low Density Urethane Foam Model
6. The time step size is based on the current density and the maximum of the instantaneous loading slope, E, and ECON. If ECON is undefined the maximum slope in the loading curve is used instead. See Also: • LS-DYNA Keyword User’s Manual
26 Materials
MAT_MOONEY_RIVLIN_RUBBER This LS-DYNA material is used to define material properties for a two-parameter material model for rubber.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
PR
Poisson’s ratio.
RO
Mass density.
A
Mooney Rivlin Constant, A
B
Mooney Rivlin Constant, B
REF
Use Reference geometry to initialize the stress tensor =0, Off = 1, On
SGL
Specimen Gauge length, l0
SW
Specimen width
ST
Specimen thickness
LCID
Load Curve Id defining the force versus actual length change (ΔL) in the gauge length.
Remarks: The strain energy density function is defined as:
W = A ( I – 3 ) + B ( II – 3 ) + C ( III
–2
– 1 ) + D ( III – 1 )
2
Materials 27 Materials
C = 0.5A + B D = A(5ν - 2) + B(11ν -5)/(2(1 - 2ν)) ν = Poisson’s ratio 2(A + B) = Shear modulus of linear elasticity I, II, III are the three invariants of the Cauchy-Green Tensor The load curve definition that provides the uniaxial data should give the change in gauge length, Δ L , versus the corresponding force. In compression both the force and the change in gauge length must be specified as negative values. In tension the force and change in gauge length should be input as positive values. The principal stretch ratio in the uniaxial direction, λ 1 , is then given by
L 0 + ΔL λ 1 = -----------------L0 with L0 being the initial length and L being the actual length. Alternatively, the stress versus strain curve can also be input by setting the gauge length, thickness, and width to unity (1.0) and defining the engineering strain in place of the change in gauge length and the nominal (engineering) stress in place of the force (Figure 2).
28 Materials
Figure 2
Uniaxial Specimen for Experimental Data
The least square fit to the experimental data is performed during the initialization phase and is a comparison between the fit and the actual input is provided in the printed file. It is a good idea to visually check to make sure that it is acceptable. The coefficients A and B are also printed in the Dyna output file. The stress versus strain curve can used instead of the force versus the change in the gauge length by setting the gauge length, thickness, and width to unity (1.0) and defining the engineering strain in place of the change in gauge length and the nominal (engineering) stress in place of the force (Figure 3).
Figure 3
Experimental Data from Uniaxial Specimen
See Also: • LS-DYNA Keyword User’s Manual
Materials 29 Materials
MAT_NONLOCAL Defines failure criterion to be dependent on the state of the material within a radius of influence which surrounds the integration point. With this failure model, the mesh size sensitivity of failure is greatly reduced, giving better convergence to a unique solution as the mesh is refined.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Non local Material identification number (Integer > 0)
PID
Part Id for non local material
P
Exponent of weighting function. A typical value might be 8., depending on the choice of the value for L.
Q
Exponent of weighting function. A typical value might be 2.
L
Characteristic length. This length should span a few elements
NFREQ
Number of time steps before updating neighbors. Since the nearest neighbor search can add significant computational time, NFREQ should be set to value of 10 to 100.
NL1,,, NL8
History variable Ids for non local treatment
XC1, YC1, ZC1
Coordinate of point on symmetry plane
XC2, YC2, ZC2
Coordinate of a point along the normal vector
See Also: • LS-DYNA Keyword User’s Manual
30 Materials
MAT_ORTHOTROPIC_ELASTIC This LS_Dyna material model (002) is an orthotropic elastic material available for solids, shells, and thick shells.
Field
Contents
Title
Unique name identifying the material model.
Desc
Optional description of the material model.
TITLE_OPTION
If selected, the material Title will be exported to LS-DYNA
MID
Material identification number. (Integer > 0)
RO
Mass density.
EA
Young’s modulus in a-direction
EB
Young’s modulus in b-direction
EC
Young’s modulus in c-direction
PRBA
Poisson’s ratio (νba)
PRCA
Poisson’s ratio (νca)
PRCB
Poisson’s ratio (νcb)
GAB
Shear modulus (Gab)
GBC
Shear modulus (Gbc)
GCA
Shear modulus (Gca)
AOPT
Material axis option
G
Shear modulus for frequency dependent damping
SIGF
Limit stress for frequency independent frictional damping
XP, YP, ZP
Coordinates for point P (for AOPT= 1 and 4)
Materials 31 Materials
Field
Contents
A1, A2, A3
Components of a vector a (for AOPT=2)
D1, D2, D3
Components of a vector d (for AOPT=2)
V1, V2, V3
Components of a vector v (for AOPT= 3 and 4)
BETA
Material angle in degrees (for AOPT= 3)
REF
Use Reference geometry to initialize the stress tensor
Remarks: The material law that relates stresses to strains is defined as: T
C = T CL T ˜ ˜ ˜ ˜ where T is a transformation matrix, and C L is the constitutive matrix defined in terms of the material ˜
˜
constants of the orthogonal material axes,
a , b , and c . The inverse of CL for the orthotropic case is ˜
defined as:
–1
CL ˜
1- ν ba ν ca ----– -------- – ------- 0 Ea Eb Ec
0
0
ν ab 1 ν cb – -------- ------ – ------- 0 Ea Eb Ec
0
0
0
0
1-------0 G ab
0
νac ν bc 1 – ------- – ------- ----Ea Eb Ec =
Note that
0
0
0
0
0
0
0
1 0 --------- 0 G bc
0
0
0
0
1 0 --------G ca
ν ab ν ba ν ca ν ac ν cb ν bc -------- = -------, ------- = ------, ------- = ------Ea Eb Ec E a Ec Eb
32 Materials
The frequency independent damping is obtained by having a spring and slider in series as shown in the following sketch:
G
σ fric This option applies only to orthotropic solid elements and affects only the deviatoric stresses. See Also: • LS-DYNA Keyword User’s Manual MAT_PIECEWISE_LINEAR_PLASTICITY Defines elasto-plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency. Also, failure based on a plastic strain or a minimum time step size can be defined.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
E
Young’s modulus. (Real > 0.0 or blank)
PR
Poisson’s ratio.
RO
Mass density.
SIGY
Yield Stress.
ETAN
Tangent modulus (ignored if LCSS.GT. 0 is defined)
Materials 33 Materials
Field
Contents
FAIL
Failure Flag LT. 0: User defined failure subroutine is called to determine failure EQ. 0.0: Failure not considered GT. 0.0: Plastic strain to failure. When the plastic strain reaches this value, the element is deleted from the calculation.
TDEL
Minimum time step size for automatic element deletion
C
Strain rate parameter, C
P
Strain rate parameter, P
LCSS
Load Curve Id or Table Id defining effective stress versus effective plastic strain. The tableId defined for each strain rate a value of load curve Id giving the stress versus effective plastic strain for that rate.
LCSR
Load Curve Id defining strain rate scaling effect on yield stress
VP
Formulation for rate effects =-1, Cowper-Symnods with deviatoric strain rate rather than total = 0, Scale yield stress = 1, Viscoplastic formulation
Remarks: The stress strain behavior may be treated by a bilinear stress strain curve by defining the tangent modulus, ETAN. The most general approach is to use the table definition (LCSS) discussed below. Three options to account for strain rate effects are possible. 1. Strain rate may be accounted for using the Cowper and Symonds model which scales the yield stress with the factor
· ε 1⁄p 1 + ---- C where, ε· is the strain rate
· ε =
· · ε ij ε ij
If VP=-1, the deviatoric strain rates are used instead. If the viscoplastic option is active, VP=1.0, and if SIGY is > 0 then the dynamic yield stress is computed from the sum of the static stress,
34 Materials
s
p
σ y ( ε eff ) which is typically given by a load curve ID, and the initial yield stress, SIGY, multiplied by the Cowper-Symonds rate term as follows: p ·p σ y ( ε eff, ε eff )
ε· eff + SIGY ⋅ ------- C p
=
s p σ y ( ε eff )
1⁄p
where the plastic strain rate is used. If SIGY=0, the following equation is used instead where the static stress s
p
σ y ( ε eff ) must be defined by a load curve: p ·p σ y ( ε eff, ε eff )
ε· eff 1 + ------- C p
=
s p σ y ( ε eff )
1⁄p
This latter equation is always used if the viscoplastic option is off. 2. For complete generality a load curve (LCSR) to scale the yield stress may be input instead. In this curve the scale factor versus strain rate is defined. 3. If different stress versus strain curves can be provided for various strain rates, the option using the reference to a table (LCSS) can be used. See figure below.
Materials 35 Materials
Figure 4
Rate effects may be accounted for by defining a table of curves. If a table Id is specified a curve Id is given for each strain rate. Intermediate values are found by interpolating between curves. Effective plastic strain versus yield stress is expected. If the strain rate values fall out of range, extrapolation is not used; rather, either the first or last curve determines the yield stress depending on whether the rate is low or high, respectively.
4. A fully viscoplastic formulation is optional (variable VP) which incorporates the different options above within the yield surface. An additional cost is incurred over the simple scaling but the improvement in results can be dramatic. See Also: • LS-DYNA Keyword User’s Manual
36 Materials
MAT_PLASTIC_KINEMATIC Defines elasto-plastic material with isotropic and kinematic hardening with or without rate effects.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
E
Young’s modulus. (Real > 0.0 or blank)
PR
Poisson’s ratio.
RO
Mass density.
SIGY
Yield Stress.
ETAN
Tangent modulus
BETA
Hardening parameter = 0: Kinematic hardening = 1: Isotropic hardening 1 < BETA > 0: Combined hardening
SRC
Strain rate parameter, C, for Cowper Symonds strain rate model. If zero, rate effects are ignored.
SRP
Strain rate parameter, P, for Cowper Symonds strain rate model. If zero, rate effects are ignored.
FS
Failure strain for eroding elements
VP
Formulation for rate effects: = 0, Scale yield stress (default) = 1, Viscoplastic formulation
Materials 37 Materials
Remarks:
Figure 5
Elastic-plastic behavior with kinematic and isotropic hardening where l0 and l are respectively undeformed and deformed lengths of uniaxial tension specimen, and Et is the slope of the bilinear stress vs. strain curve.
Strain rate may be accounted for using the Cowper and Symonds model which scales the yield stress with the factor
· ε 1⁄p 1 + ---- C where, ε· is the strain rate
38 Materials
· ε =
· · ε ij ε ij
A fully viscoplastic formulation is optional which incorporates the Cowper and Symonds formulation within the yield surface. Although an additional computational cost is incurred, the improvement in the results can be substantial. To ignore strain rate effects, set both SRC and SRP to zero. See Also: • LS-DYNA Keyword User’s Manual MAT_POWER_LAW_PLASTICITY Defines an isotropic plasticity material model with rate effects which uses a power law for hardening.
Field
Contents
Name
Unique name identifying the material model.
Desc
Optional description of the material model.
Fields: MID
Material identification number. (Integer > 0)
RO
Mass density.
E
Young’s modulus. (Real > 0.0 or blank)
PR
Poisson’s ratio.
K
Strength coefficient
N
Hardening exponent
SRC
Strain rate parameter, C. If zero, rate effects are ignored.
SRP
Strain rate parameter, P. If zero, rate effects are ignored.
Materials 39 Materials
Field
Contents
SIGY
Yield Stress (optional). Generally this parameter is not necessary (See Remarks)
VP
Formulation for rate effects: = 0, Scale yield stress (default) = 1, Viscoplastic formulation
Remarks: The yield stress, σy is a function of plastic strain, and obeys the following equation:
σ y = k ε n = k ( ε yp + ε p )
n
where, ε· yp is the strain rate to yield, and ε p is the effective plastic strain (logarithmic). The parameter SIGY governs how the strain to yield is identified. If SIGY is set to zero, the strain to yield is found by solving for the intersection of the linear elastic loading with the strain hardening equation:
σ = Eε σ =kεn which gives the elastic strain at yield as: 1
ε yp
E n −1 = k
If SIGY is set to nonzero, and greater than 0.02 then: 1
ε yp
σ n = y k
40 Materials
Strain rate is accounted for using the Cowper-Symonds model which scales the yield stress with the following factor:
ε 1+ C
1
P
where ε· is the strain rate. A fully viscoplastic formulation is optional with this model which incorporates the Cowper-Symonds formulation within the yield surface. Although an additional cost
is incurred, the improvement in results can be substantial. See Also: • LS-DYNA Keyword User’s Manual MAT_RIGID This material model is used to model parts made from rigid materials. Also, the coupling of a rigid body with MADYMO, and CAL3D can be defined via this material. Alternatively, a VDA surface can be attached as surface to model the geometry, e.g., for the tooling in metal-forming applications. Also, global and local constraints on the mass center can be optionally defined. Optionally, a local consideration for output and user-defined airbag sensors can be chosen.
Field
Contents
Title
Unique name identifying the material model.
Desc
Optional description of the material model.
TITLE_OPTION
If selected, the material Title will be exported to LS-DYNA
MID
Material identification number. (Integer > 0)
Materials 41 Materials
Field
Contents
RO
Mass density
E
Young’s modulus. (Real > 0.0 or blank)
PR
Poisson’s ratio
N
MADYMO3D coupling flag.
COUPLE
Coupling Option
ALIAS
VDA Surface alias Name
CMO
Center of mass constraint option =1, Constraints applied in global directions =0, No constraints =-1, Constraints applied in local directions
CON1
First constraint parameter =0, No constraints =1, Constrained x displacement =2, Constrained y displacement =3, Constrained z displacement =4, Constrained x and y displacements =5, Constrained y and z displacements =6, Constrained z and x displacements =7, Constrained x, y, and z displacements
42 Materials
Field CON2
Contents Second constraint parameter =0, No constraints =1, Constrained x rotation =2, Constrained y rotation =3, Constrained z rotation =4, Constrained x and y rotations =5, Constrained y and z rotations =6, Constrained z and x rotations =7, Constrained x, y, and z rotations
LCO
Local coordinate system for output
A1-V3
The components of two vectors a and v fixed in the rigid body for output.
Remarks: 1. A rigid material provides a convenient way of turning one or more parts comprised of beams, shells, or solid elements into a rigid body. Approximating a deformable body as rigid is a preferred modeling technique in many real world applications. For example, an engine block in a car crash simulation can be treated as rigid. Elements belonging to a rigid material are bypassed in the element processing and no storage is allocated for storing history variables. Consequently, using a rigid material is very cost efficient. 2. The inertial properties are calculated from the geometry of the constituent elements and the density RO as specified on the MAT_RIGID. 3. The initial velocity of a rigid material is calculated from the initial velocity of the constituent grids. 4. A rigid body can be made up of disjoint meshes. All elements that are part of a rigid body will move together as one rigid, even if they are disjoint. 5. Motion control for a rigid material can be defined using the BOUNDARY_SPC entry. The SPC must be applied to one grid point only. 6. Load control for a rigid material can be defined using the FORCE and MOMENT entries. These loads can be applied to any grid point that belongs to the rigid body. The forces and moments acting on the grid points will be accumulated and applied to the rigid body. 7. If no constraints are specified for the rigid material (CMO=0) the nodes belonging to the rigid material are scanned to determine constraints of the rigid material in global directions. If constraints are specified for the rigid material (CMO equal to +1 or –1), the nodes belonging to the rigid material are not scanned
Materials 43 Materials
8. Constraint directions for rigid materials (CMO equal to +1 or –1) are fixed, that is, not updated, with time. See Also: • LS-DYNA Keyword User’s Manual MAT_SEATBELT This material model is used to define the stretch characteristics and mass properties for seat belts.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
MPUL
Mass per unit length
LLCID
Load curve Id for loading (Force vs. engineering strain)
ULCID
Load curve Id for unloading (Force vs. engineering strain)
LMIN
Minimum length for elements connected to slip rings and retractors
Remarks: 1. The Load curves for loading and unloading should start at the origin (0, 0), and contain positive force and strain values only. The belt material is tension only, with zero forces being calculated whenever the strain becomes negative (compressive). The first nonzero point on the loading curve defines the initial yield point of the material. On unloading, the unloading curve is shifted along the strain axis until it crosses the loading curve at the yield point from which unloading starts. If the initial yield has not yet exceeded, or the origin of the (shifted) unloading curve is at negative strain, the original loading curve will be used for both loading and unloading. If the strain is less than the strain at the origin of the unloading curve, the belt is slack, and no force is generated. Otherwise, forces will be determined by the unloading curve for unloading, and reloading until the strain again exceeds yield after which the loading curve will again be used.
44 Materials
2. A small amount of damping is automatically included, to reduce high frequency oscillation. The damping force, D opposes the relative motion of the nodes, and is limited by stability: D = (0.1 X Mass X Relative velocity)/(Time step size) The magnitude of the damping force is limited to one-tenth of the force calculated from the force vs. strain relationship, and is zero when the belt is slack. Damping forces are not applied to elements attached to slip rings and retractors. See Also: • LS-DYNA Keyword User’s Manual MAT_SOIL_AND_FOAM This simple material model works similar to fluid. It should be used only in situations when soils and foams are confined within a structure or when geometric boundaries are present.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear modulus
BULK
Bulk modulus for unloading
A0, A1, A2
Yield function constants
PC
Pressure cut off for tensile fracture
VCR
Volumetric crushing option: 0.0: on, 1.0: loading and unloading paths are the same
Materials 45 Materials
Field
Comments
REF
use reference geometry to initialize the pressure
LCID
Load curve Id defining pressure vs. volumetric strain
Remarks: 1. Pressure is positive in compression 2. Volumetric strain is given by the natural log of the relative volume and is negative in compression 3. Relative volume is the ratio of current volume to the initial volume at the start of the calculation 4. If the pressure drops below the cutoff value specified, it is reset to that value See Also: • LS-DYNA Keyword User’s Manual MAT_VISCOELASTIC This material model is used to define viscoelastic behavior for beams (Hughes-Liu), shells, and solids
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
BULK
Bulk modulus for unloading
G0
Short time shear modulus
GI
long time (Infinite) Shear modulus
BETA
Decay constant
Remarks: 1. The shear relaxation behavior is described by [Hermann and Peterson, 1968]:
G ( t ) = GI + ( G0 – GI )e
– βt
46 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_HIGH_EXPLOSIVE_BURN This material model is used to input the detonation properties of high explosive materials.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
D
Detonation Velocity
PCJ
Chapman-Jouget pressure
BETA
Beta burn flag 0: Beta and programmed burn 1: Beta burn only 2: Programmed burn only
K
Bulk Modulus (Beta = 2)
G
Shear Modulus (Beta = 2)
SIGY
Yield Stress (Beta = 2)
See Also: • LS-DYNA Keyword User’s Manual
Materials 47 Materials
MAT_NULL The use of this material model allows equations of state without computing deviatoric stresses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
PC
Pressure Cutoff
MU
Dynamic Viscosity Coefficient
TEROD
Relative Volume for Erosion in Tension
CEROD
Relative Volume for Erosion in Compression
YM
Young’s Modulus (used for null beams and shells only)
PR
Poisson’s ratio (used for nul beams and shells only)
See Also: • LS-DYNA Keyword User’s Manual
48 Materials
MAT_ELASTIC_PLASTIC_HYDRO This material model is used to model an elastic-plastic hydrodynamic material.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
SIGY
Yield Stress
EH
Plastic hardening modulus
PC
Pressure Cutoff
FS
Failure strain for Erosion
LCID
Load curve Id defining pressure vs. volumetric strain
See Also: • LS-DYNA Keyword User’s Manual
Materials 49 Materials
MAT_ELASTIC_PLASTIC_HYDRO_SPALL This material model is used to model an elastic-plastic hydrodynamic material with spall to represent splitting, cracking, and failure under tensile loads.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
SIGY
Yield Stress
EH
Plastic hardening modulus
PC
Pressure Cutoff
FS
Failure strain for Erosion
A1
Linear Pressure Hardening Coefficient
A2
Quadratic Pressure Hardening Coefficient
SPALL
Spall Type
LCID
Load curve Id defining pressure vs. volumetric strain
See Also: • LS-DYNA Keyword User’s Manual
50 Materials
MAT_STEINBERG This material model is used to model materials deforming at very high strain rate for use with solid elements. The yield strength is a function of temperature and pressure.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G0
Basic shear modulus
SIG0
Yield Stress, σ0
BETA
Parameter β, used in the equation defining Yield Strength
N
Parameter n, used in the equation defininig Yield Strength
GAMA
Initial Plastic Strain γi
SIGM
σm
B
Parameter b, used in the equation defininig Yield Strength
BP
Parameter b' , used in the equation defininig Yield Strength
H
Parameter h, used in the equation defininig Yield Strength
F
Parameter b, used in the equation defininig Yield Strength
A
Atomic Weight
TM0
Melting Temperature
Materials 51 Materials
Field
Comments
GAM0
Yield Stress equation Parameter, Gama_0
SA
Melting Temperature equation Parameter, a
PC
Pressure Cutoff
SPALL
Spall Type 0: Default set to 2.0 1: P >= PC 2: if σmax >= -PC, element spalls and tension, p < 0, is never allowed 3: P< -PC, element spalls and tension, p < 0, is never allowed
RP
Melting Temperature equation parameter, r'
FLAG
Set 1 for μ coefficients for the cold compression energy fit
NMN
Optional minimum value for μ or η
NMX
Optional maximum value for μ or η
ECi
Cold Compression Energy coefficients
See Also: • LS-DYNA Keyword User’s Manual
52 Materials
MAT_STEINBERG_LUND This material model is used to input the properties of a Steinberg and Lund [1999].material model for including the strain rate effect.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G0
Basic shear modulus
SIG0
Yield Stress, σ0
BETA
Parameter β, used in the equation defininig Yield Strength
N
Parameter n, used in the equation defininig Yield Strength
GAMA
Initial Plastic Strain γi
SIGM
σm
B
Parameter b, used in the equation defininig Yield Strength
BP
Parameter b' , used in the equation defininig Yield Strength
H
Parameter h, used in the equation defininig Yield Strength
F
Parameter b, used in the equation defininig Yield Strength
Materials 53 Materials
Field
Comments
A
Atomic Weight
TM0
Melting Temperature
GAM0
Yield Stress equation Parameter, Gama_0
SA
Melting Temperature equation Parameter, a
PC
Pressure Cutoff
SPALL
Spall Type 0: Default set to 2.0 1: P >= PC 2: if σmax >= -PC, element spalls and tension, p < 0, is never allowed 3: P< -PC, element spalls and tension, p < 0, is never allowed
RP
Melting Temperature equation parameter, r'
FLAG
Set 1 for μ coeeficients for the cold compression energy fit
NMN
Optional minimum value for μ or η
NMX
Optional maximum value for μ or η
ECi
Cold Compression Energy coefficients
UK
Activation Energy for rate dependent model
C1
Exponent prefactor in rate dependent model
C2
Coefficient of drag term rate dependent model
YP
Peierls stress for rate dependent model
YA
Ahtermal yield stress for rate dependent model
YM
Work hardening max for rate dependent model
See Also: • LS-DYNA Keyword User’s Manual
54 Materials
MAT_ISOTROPIC_ELASTIC_FAILURE This material model is used to define the properties of a non-iterative plasticity model with simple plastic strain failure criteria.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus
BULK
Bulk Modulus
EPF
Plastic Failure Strain
PRF
Failure Pressure
REM
Element Erosion option 0: Eroded at failure 1: no removal of element, (except if TERM = 1, and element time step size falls below Δt)
TREM
Δt for element removal 0: Δt is not considered 1: yes, if element time step size falls below Δt
Materials 55 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_SOIL_AND_FOAM_FAILURE This material model is used to define the material properties for a soil and foam model. This material model works similar to fluid, and should be used only in situations when soils and foams are confined within a structure or when geometric boundaries are present.In this material model, the material loses its ability to carry tension when the pressure exceeds the failure pressure.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
BULK
Bulk Modulus for unloading
A0, A1, A2
Plastic Yield Function Constants
PC
Pressure Cutoff for Tensile Fracture
VCR
Volumetric Crushing Option 0: On 1: Loading and unloading paths are the same
56 Materials
Field REF
Comments Use reference geometry to initialize pressure 0: Off 1:On
LCID
Load Curve Id defining pressure vs. volumetric strain
See Also: • LS-DYNA Keyword User’s Manual MAT_JOHNSON_COOK The Johnson-Cook material model is a strain and temperature sensitive plasticity model. It is sometimes used for materials with a large variation in the strain rate, and/or undergoing softening due to plastic heating.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
Materials 57 Materials
Field
Comments
E
Young’s Modulus (for shell elements only)
PR
Poisson’s Ratio (for shell elements only)
DTF
Minimum Time step for Automatic Shell Element Deletion
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: ViscoPlastic Formulation
RATEOP
Optional forms of strain-rate term: .EQ. 0: Log-Linear Johnson-Cook (default) .EQ. 1: Log-Quadratic Huh-Kang (2 parameters) .EQ. 2: Exponential Allen-Rule_jones .EQ. 3: Exponential Cowper-Symonds (2 parameters)
A, B, N, C, M
Constants to define the flow stress equation
TM
Melt Temperature
TR
Room Temperature
EPSO
Effective Plastic Strain Rate depends on Time Unit
CP
Specific Heat
PC
Pressure Cutoff (Pmin< 0.0)
SPALL
Spall Type 0: Default set to 2.0 1: P >= PC 2: if σmax >= -PC, element spalls and tension, p < 0, is never allowed 3: P< -PC, element spalls and tension, p < 0, is never allowed
IT
Plastic Strain Iteration 0: No Iteration 1: Accurative Iteration Solution
Di
Failure Parameters
C2/P
Optional strain-rate parameter for Huh-Kang (C2), or Cowper-Symonds (P) forms.
58 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_PSEUDO_TENSOR This material model is used to define the properties a pseudo-tensor material model. This has been used to analyze buried steel reinforced concrete structures subjected to impulsive loadings.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
PR
Poisson’s Ratio
SIGF
Tension Cutoff (Maximum Principal Stress at failure)
A0
Cohesion
A1, A2
Pressure Hardening Coefficients
A0F
Cohesion for failed material
A1F
Pressure hardening coefficient for failed material
B1
Damage Scaling Factor
PER
Percent Reinforcement
Materials 59 Materials
Field
Comments
ER
Young’s Modulus for Reinforcement
PRR
Poisson’s Ratio for Reinforcement
SIGY
Initial Yield Stress
ETAN
Tangent Modulus/Plastic Hardening Modulus
LCP
Load Curve Id defining rate sensitivity for principal material
LCR
Load Curve Id defining rate sensitivity for reinforcement
LCID
Load Curve defining Yield Stress (or scale factor) vs. effective plastic strains, damages, or pressures
See Also: • LS-DYNA Keyword User’s Manual MAT_ORIENTED_CRACK Defines the properties of brittle materials failing due to large tensile stresses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus
FS
Fracture Stress
PRF
Fracture Pressure
60 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_STRAIN_RATE_DEPENDENT_PLASTICITY Defines the properties of a strain rate dependent material.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
LC1
Load Curve Id for Yield Stress σ0 vs. effective strain rate
ETAN
Tangent Modulus
LC2
Load Curve Id for Young’s Modulus vs. effective strain rate
LC3
Load Curve Id for Tangent Modulus vs. effective strain rate
LC4
Load Curve Id for von Mises stress at failure vs. effective strain rate
TDEL
Time Step Size for Automatic Element Deletion (shell elements only)
RDEF
Redefinition of failure curve 1: Effective plastic strain 2: Maximum principal stress
Materials 61 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_ORTHOTROPIC_THERMAL Defines the properties of a linear elastic material with temperature dependent orthotropic properties.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA, EB, EC
Young’s Moduli in the A, B and C direction
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in the ab, bc and ca directions
AA, AB, AC
Coefficients of Thermal Expansion in the a, b, and c directions
62 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of local c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the center line axis. This option is for solid elements only.
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT = 3
REF
Use Reference Geometry to initialize stress tensor (0 = off; 1 = on)
See Also: • LS-DYNA Keyword User’s Manual
Materials 63 Materials
MAT_COMPOSITE_DAMAGE Defines the properties of an orthrotropic material with optional brittle failure for composites.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA, EB, EC
Young’s Moduli in the A, B and C direction
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in the ab, bc and ca directions
KF
Bulk Modulus of failed material
64 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle
SC
Shear Strength, ab plane
XT
Longitudinal Tensile Strength, a-axis
YT
Transverse Tensile Strength, b-axis
YC
Transverse Compression Strength, b-axis
ALPH
Shear Stress Parameter for nonlinear term (0- 0.5)
SN
Normal Tensile Strength (solid elements only)
SYX
Transverse Shear Strength (solid elements only)
SZX
Transverse Shear Strength (solid elements only)
See Also: • LS-DYNA Keyword User’s Manual
Materials 65 Materials
MAT_TEMPERATURE_DEPENDENT_ORTHOTROPIC Defines the properties of an orthotropic elastic material with arbitrary temperature dependency.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
66 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
REF
Use Reference Geometry to initialize stress tensor (0 = off; 1 = on)
MACF
Material axes change flag for brick element: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle
EA_LC, EB_LC, EC_LC
Load curve defining Young’s Moduli in the a, b and c directions, respecively, vs. Temperature
PRBA_LC
Load curve defining Poisson’s Ratios in the ba directionsvs. Temperature
PRCA_LC
Load curve defining Poisson’s Ratios in the ca directionsvs. Temperature
PRCB_LC
Load curve defining Poisson’s Ratios in the cb directionsvs. Temperature
Materials 67 Materials
Field
Comments
AA_LC, AB_LC, AC_LC
Load curves defining Coefficients of Thermal Expansion in the a, b, and c directions, respectively, vs. Temperature
GAB_LC
Load curve defining Shear modulus in the ab plane vs. Temperature
GBC_LC
Load curve defining Shear modulus in the bc plane vs. Temperature
GCA_LC
Load curve defining Shear modulus in the ca plane vs. Temperature
See Also: • LS-DYNA Keyword User’s Manual MAT_GEOLOGIC_CAP_MODEL Defines the properties for geomechanical problems or materials like concrete.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
BULK
Initial Bulk Modulus
G
Initial Shear Modulus
ALPHA
Failure Envelope Parameter
THETA
Failure Envelope Linear coefficient
GAMMA
Failure Envelope Exponential coefficient
BETA
Failure Envelope Exponent
R
Cap, surface axis ratio
68 Materials
Field
Comments
D
Hardening law exponent
W
Hardening law coefficient
X0
Hardening Law Exponent
C
Kinematic Hardening Coefficient
N
Kinematic Hardening Parameter
PLOT
Plotting Flag for LS-Taurus
FTYPE
Formulation Flag 1: Soil or concrete 2: Rock
VEC
Vectorization Flag 0: Vectorized with a fixed number of iterations 1: Fully Iterative
TOFF
Tension Cutoff
See Also: • LS-DYNA Keyword User’s Manual
Materials 69 Materials
MAT_HONEYCOMB Defines the properties for honeycomb and foam materials with real anisotropic behavior.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress for fully compacted Honeycomb
VF
Relative Volume at which Honeycomb is fully compacted
MU
Material Viscosity Coefficient
BULK
Bulk Viscosity Flag 0: Bulk Viscosity Not Used 1: Bulk Viscosity Active and MU=0
LCA
Load Curve Id for (Sigma_aa vs. either Relative Volume or Volumetric Strain
LCB
Load Curve Id for (Sigma_bb vs. either Relative Volume or Volumetric Strain (Default LCB = LCA)
70 Materials
Field
Comments
LCC
Load Curve Id for (Sigma_cc vs. either Relative Volume or Volumetric Strain (Default LCC = LCA)
LCS
Load Curve Id for (shear stress vs. either Relative Volume or Volumetric Strain (Default LCS = LCA)
LCAB
Load Curve Id for (Sigma_ab vs. either Relative Volume or Volumetric Strain (Default LCAB = LCS)
LCBC
Load Curve Id for (Sigma_bc vs. either Relative Volume or Volumetric Strain (Default LCBC = LCS)
LCCA
Load Curve Id for (Sigma_ca vs. either Relative Volume or Volumetric Strain (Default LCCA = LCS)
LCSR
Load Curve Id for strain rate effects defining the scale factor vs. strain rate. The curves defined above are scaled using this curve.
EAAU, EBBU, ECCU
Elastic Moduli in uncompressed configuration in aa, bb, and cc directions
GABU, GBCU, GCAU
Shear Moduli in uncompressed configuration in ab, bc, and ca planes
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
XP
x-coordinate of point p, for AOPT = 1
YP
y-coordinate of point p, for AOPT = 1
ZP
z-coordinate of point p, for AOPT = 1
Ai
Component of vector a, for AOPT = 2
Di
Component of vector d, for AOPT = 2
TSEF
Tensile Strain at Element Failure
SSEF
Shear Strain at Element Failure
See Also: • LS-DYNA Keyword User’s Manual
Materials 71 Materials
MAT_RESULTANT_PLASTICITY Defines a resultant formulation material model, including elastoplastic behavior.for beam and shell elements,
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus (shell elements only)
See Also: • LS-DYNA Keyword User’s Manual
72 Materials
MAT_FORCE_LIMITED This material model allows the simulation of plastic hinge formation at the ends of a beam, using a curve definition (for Belytschko-Schwer beam only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
DF
Damping Factor
AOPT
Axial Load Curve Option 0: Force vs. Strain 1: Force vs. Change in Length
M1, M2,,,,, M8
Applied end moment for force vs. strain/ or change in length curve. A minimum of one, and a maximum of eight must be defined.
LC1, LC2, ..., LC8
Load Curve Ids applied end moment
Materials 73 Materials
Field
Comments
LPSi
Load Curve Id for plastic moment vs. rotation about s-axis at node i
SFSi
Scale factor, plastic moment vs. rotation about s- axis at node i
YMSi
Yield moment about s- axis at node i for interaction calculations
LPTi
Load Curve Id for plastic moment vs. rotation about t-axis at node i
SFTi
Scale factor, plastic moment vs. rotation about t- axis at node i
YMTi
Yield moment about t- axis at node i for interaction calculations
LPR
Load Curve Id for plastic torsional moment vs. rotation
SFR
Scale factor for plastic torsional moment vs. rotation
YMR
Torsional yield moment for interaction calculations
See Also: • LS-DYNA Keyword User’s Manual MAT_SHAPE_MEMORY Defines the superplastic response present in shape memory alloys (SMA).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIG_ASS
Starting value for the forward phase transformation
74 Materials
Field
Comments
SIG_ASF
Final value for the forward phase transformation
SIG_SAS
Starting value for the reverse phase transformations
SIG_SAF
Final value for the reverse phase transformation
EPSL
Recoverable strain or maximum residual strain
ALPHA
Parameter Measuring the difference between material response in tension and compression
YMRT
Young’s Modulus for Martensite
LC_ASS
Load Curve Id for Starting value of forward phase transformation
LC_ASF
Load Curve Id for Final value of forward phase transformation
LC_SAS
Load Curve Id for Starting value of reverse phase transformations
LC_SAF
Load Curve Id for Final value of reverse phase transformation
See Also: • LS-DYNA Keyword User’s Manual MAT_FRAZER_NASH_RUBBER_MODEL Defines rubber from uniaxial test data.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
Materials 75 Materials
Field
Comments
RO
Mass Density of the material
PR
Poisson’s Ratio
C100, C200, C300, C400, C110, C210, C010, C020
Strain Energy Parameters
EXIT
Exit option of strain limit 0: Stop if limit exceeds 1: Continue even if limit exceeds
EMAX
Maximum Strain Limit
EMIN
Minimum Strain Limit
REF
Use Reference Geometry to initialize stress tensor 0: Off 1: On
SGL
Specimen Gauge Length
SW
Specimen Width
ST
Specimen Thickness
LCID
Load Curve Id defining Force vs. Actual Change in gauge Length
See Also: • LS-DYNA Keyword User’s Manual
76 Materials
MAT_LAMINATED_GLASS Defines layered glass including polymeric layers.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EG
Young’s Modulus for Glass
PRG
Poisson’s Ratio for Glass
SYG
Yield Strength for Glass
ETG
Plastic Hardening Modulus for Glass
EFG
Plastic Strain at Failure for Glass
EP
Young’s Modulus for Polymer
PRP
Poisson’s Ratio for Polymer
SYP
Yield Strength for Polymer
ETP
Plastic Hardening Modulus for Polymer
NUM_RFS
Number of Integration Points of Material
F1, F2,, ..., FN
Integration Point Material Fi = 0: glass; Fi = 1: polymer
Materials 77 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_BARLAT_ANISOTROPIC_PLASTICITY Defines the properties of an anisotropic material behavior during forming processes.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
K
Strength Coefficient
E0
Strain corresponding to initial yield
N
Hardening exponent for yield strength
M
Flow potential exponent in Barlat’s model
A, B, C, F, G, H
Anisotropic Coefficients in Barlat’s model
LCID
Load Curve Id defining effective Stress vs. effective Plastic Strain
78 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by offsetting the material axes by an angle, OFFANG, from a line defined by the cross product of the vector v with the normal to the plane of a shell element, or mid surface of a brick element.
BETA
Offset angle (for AOPT = 3)
MACF
Material axes change flag for brick element: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual
Materials 79 Materials
MAT_BARLAT_YLD96 Defines the properties of an anisotropic material behavior during forming processes, especially for aluminum alloys (only for shell elements only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
K
Strength Coefficient
E0
Strain corresponding to initial yield
N
Hardening exponent for yield strength
ESRO
εSRO, in power law rate sensitivity
M
Exponent, m for strain rate effects
80 Materials
Field HARD
Comments Hardening option 0)
RO
Mass Density of the material
EA
Young’s Modulus, Longitudinal Direction
EB
Young’s Modulus, Transverse Direction
EC
Young’s Modulus, Normal Direction
PRBA, PRCA, PRCB
Poisson’s Ratio in ba, ca, and cb directions
GAB, GBC, BCA
Shear Moduli in ab., bc, and ca directions
82 Materials
Field CSE
Comments Compressive Stress Elimination Option 0: Don’t Eliminate 1: Eliminate
EL
Young’s Modulus for Elastic Liner
PRL
Poisson’s Ratio for Elastic Liner
LRATIO
Ratio of linear thickness to total fabric thickness
DAMP
Rayleigh Damping Coefficient
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
FLC
Fabric Leakage coefficient
FAC
Fabric Area Coefficient
ELA
Effective Leakage Area for blocked fabric
LNRC
Liner Compression Flag 0: Off 1:On
Materials 83 Materials
Field FORM
Comments Flag to modify Membrane Formulation for fabric material: 0: default 1: in variant Local Coordinate System 2: Green-Lagrange strain formulation 3: Large Strain with nonorthogonal material angles 4: Large Strainwith nonorthogonal material angles, and nonlinear material stress strain behavior. Define optional Load Curve Ids.
FVOPT
Fabric Venting Option 1: Wang-Nefske formulas for venting, through orifice, with no blockage. 2: Wang-Nefske formulas for venting through orifice, with blockage. 3: Graefe, Krummheurer, and Siejak [1990] Leakage formulas with no blockage. 4: Graefe, Krummheurer, and Siejak [1990] Leakage formulas with blockage. 5: Leakage formulas based on flow through a porous media, with no blockage. 6: Leakage formulas based on flow through a porous media, with blockage.
TSRFAC
Tensile Stress Cutoff Reduction factor
blank1, blank2, blank3
Blank Fields
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
LCA
Load Curve Id for Stress vs. Strain along the a- axis
LCB
Load Curve Id for Stress vs. Strain along the b- axis
LCAB
Load Curve Id for Stress vs. Strain in the ab plane
LCUA
Unload/Reload Curve Id for Stress vs. Strain along a- axis
LCUB
Unload/Reload Curve Id for Stress vs. Strain along b- axis
LCUAB
Unload/Reload Curve Id for Stress vs. Strain in the ab plane
LC_FLC
Load Curve Id for Fabric Leakage Coefficient
84 Materials
Field
Comments
LC_FAC
Load Curve Id for Fabric Area Coefficient
LC_ELA
Load Curve Id for Effective Leakage Area for blocked fabric
LC_TSR
Load Curve Id for Tensile Stress Cutoff Reduction factor vs. Time
See Also: • LS-DYNA Keyword User’s Manual MAT_PLASTIC_GREEN-NAGHDI_RATE This model is available for brick elements only. It is similar to MAT_PLASTIC_KINEMATIC, but uses the Green-Naghdi Rate formulation for the stress update.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Strength
ETAN
Plastic Hardening Modulus
SRC
Strain Rate Parameter
SRP
Strain Rate Parameter
BETA
Hardening Parameter
See Also: • LS-DYNA Keyword User’s Manual
Materials 85 Materials
MAT_3-PARAMETER_BARLAT This material model is designed for modeling sheets with anisotropic materials under plane stress conditions.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
HR
Hardening Rule 1: Linear 2: Exponential 3: Load Curve
P1, P2
Material Parameters
86 Materials
Field ITER
Comments Iteration Flag 0: Fully iterative 1: Fixed to 3 iterations
M
Exponent in Barlat’s yield surface
R00, R45, R90
Lankford Parameters
LCID
Load Curve Id for hardening rule
Epsilon_0
ε0 for determining initial yield stress for exponential hardening
SPI
Parameter to redefine ε0
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
blank1, blank2, blank3
Blank Fields
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
Materials 87 Materials
MAT_TRANS_ANISO_ELASPLASTIC Simulates sheet forming processes with anisotropic material. Only transverse anisotropy can be considered.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus
R
Anisotropic Hardening Parameter
HLCID
Load Curve Id for Effective Yield Stress vs. Effective Plastic Strain
See Also: • LS-DYNA Keyword User’s Manual
88 Materials
MAT_TRANS_ANISO_ELASPLASTIC_ECHANGE Simulates sheet forming processes with anisotropic material. Only transverse anisotropy can be considered.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus
R
Anisotropic Hardening Parameter
HLCID
Load Curve Id for Effective Yield Stress vs. Effective Plastic Strain
IDSCALE
Load curve Id defining the scale factor for Young’s modulus change with respect to effective strain. Note: if EA, and COE are defined, this curve is not necessary.
EA, COE
Coefficients (EA and ζ) defining Young’s modulus with respect to the effective strain. Note: if EA, and COE are defined, this curve is not necessary.
See Also: • LS-DYNA Keyword User’s Manual
Materials 89 Materials
MAT_BLATZ-KO_FOAM Defines the properties for rubber like foams of polyurethane. It is a simple one parameter model with a fixed Poisson’s ratio of 0.25.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
REF
Use Reference Geometry to initialize stress tensor
See Also: • LS-DYNA Keyword User’s Manual
90 Materials
MAT_FLD_TRANSVERSELY_ANISOTROPIC Simulates sheet forming processes with anisotropic material. Only transverse anisotropy can be considered.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Plastic Hardening Modulus
R
Anisotropic Hardening Modulus
HLCID
Load Curve Id defining Effective Yield Stress vs. Effective Plastic Strain
LCIDFLD
Load Curve Id defining the Forming Limit Diagram (major vs. minor strain)
See Also: • LS-DYNA Keyword User’s Manual
Materials 91 Materials
MAT_NONLINEAR_ORTHOTROPIC Defines an orthotropic nonlinear elastic material based on a finite strain formulation with initial geometry as the reference. Optional failure and stiffness properties are available.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EAA, EBB, ECC
Young’s Modulus in the A, B and C directions
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca and cb directions
GAB, GBC, GCA
Shear Modulus in the ab, bc and ca directions
DT
Temperature increment for stress stabilization
TRAMP
Time to ramp up to the final temperature
ALPHA
Thermal expansion coefficient
LCIDA, LCIDB, LCIDC Load Curve Id for nominal stress vs. nominal strain in the a- , b-, and c-axes EFAIL
Failure Strain
92 Materials
Field
Comments
DTFAIL
Timestep size criteria for element erosion
CDAMP
Damping Coefficient
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
blank1, blank2, blank3
Blank Fields
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
LCIDAB, LCIDBC, LCIDCA
Load Curve Id for nominal shear stress vs. nominal shear strain in the ab, bc, and ca plane
See Also: • LS-DYNA Keyword User’s Manual
Materials 93 Materials
MAT_BAMMAN Defines a material with temperature and rate dependent plasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
T
Initial Temperature
HC
Heat Generation Coefficient
Ci
Input parameters
Ai
Initial value of state variable i
KAPPA
Initial value of internal state variable 6 (κ)
See Also: • LS-DYNA Keyword User’s Manual
94 Materials
MAT_BAMMAN_DAMAGE Defines a material with temperature and rate dependent plasticity including damage in the modeling.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
T
Initial Temperature
HC
Heat Generation Coefficient
Ci
Input parameter
Ai
Initial value of state variable i
N
Exponent in damage evaluation
D0
Initial Damage (porosity)
FS
Failure Strain for Erosion
Materials 95 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_CLOSED_CELL_FOAM Defines a low density, closed polyurethane foam for simulating impact limiters in automotive applications.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
A, B, C
Factors a, b, and c for Yield Stress definition
P0
Initial Foam Pressure
PHI
Ratio of Foam to Polymer Density
GAMA0
Initial Volumetric Strain
LCID
Load Curve Id defining vonMises Stress vs. Volumetric Strain
See Also: • LS-DYNA Keyword User’s Manual
96 Materials
MAT_ENHANCED_COMPOSITE_DAMAGE Defines the properties of an orthrotropic material with optional brittle failure for composites. This is an enhanced version of MAT_COMPOSITE_DAMAGE (MAT_022).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus, Longitudinal Direction
EB
Young’s Modulus, Transverse Direction
EC
Young’s Modulus, Normal Direction (NOT used)
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca, and cb planes (PRCA, PRCB NOT used)
GAB, GBC, GCA
Shear Modulus in the ab, bc, and ca planes
KF
Bulk Modulus of failed material (NOT used)
Materials 97 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
bl1, bl2, bl3
Blank Fields
Ai
Components of Vector a, for AOPT=2
MANGLE
Material Angle (Degrees), for AOPT=3
Vi
Components of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
DFAILM
Maximum Strain for matrix straining in tension/compression
DFAILS
Maximum shear strain
TFAIL
Timestep size criteria for element deletion
ALPH
Shear Stress Parameter for NonLinear Term
SOFT
Softening Reduction Factor
FBRT
Softening of fiber Tensile Strength
YCFAC
Reduction Factor for compressive fiber strength, after matrix failure
DFAILT
Maximum Strain for fiber in tension
DFAILC
Maximum Strain for fiber in compression
EFS
Effective Failure Strain
XC
Longitudinal Compression Strength
XT
Longitudinal Tensile Strength
YC
Transverse Compression Strength
YT
Transverse Tensile Strength
SC
Shear Strength, ab plane
98 Materials
Field CRIT
Comments Failure Criteria (Material Number) 54: Chang matrix failure criterion 55: Tsai-Wu matrix failure criterion
BETA
Weight Factor for Shear term in tensile fiber mode
See Also: • LS-DYNA Keyword User’s Manual
Materials 99 Materials
MAT_LAMINATED_COMPOSITE_FABRIC Defines a composite material with unidirectional layers, complete laminates and woven fabrics (for shell elements only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus, Longitudinal Direction
EB
Young’s Modulus, Transverse Direction
EC
Young’s Modulus, Normal Direction (NOT used)
PRBA
Poisson’s Ratio in BA direction
100 Materials
Field
Comments
TAU1
Stress limit of first slightly nonlinear part of Shear Stress vs. Shear Strain curve
GAMMA1
Strain limit of first slightly nonlinear part of Shear Stress vs. Shear Strain curve
SLIMT1
Factor to determine the minimum Stress Limit after Stress Maximum (fiber Tension)
SLIMC1
Factor to determine the minimum Stress Limit after Stress Maximum (fiber Compression)
SLIMS
Factor to determine the minimum Stress Limit after Stress Maximum (Shear)
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
TSIZE
Time step size for Automatic Element Deletion
ERODS
Maximum Element Strain for Element Layer Failure
SOFT
Softening Reduction Factor in Crash front
FS
Failure Surface Type 1: Smooth surface Failure with Quadratic criteria for both fiber and transverse directions 0: Smooth surface Failure with Quadratic criteria for transverse direction, with a limiting value in the fiber direction -1: Faceted Failure surface
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
Materials 101 Materials
Field
Comments
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
E11C
Strain at Longitudinal Compression Strength, a-axis
E11T
Strain at Longitudinal Tensile Strength, a-axis
E22C
Strain at Transverse Compression Strength, b-axis
E22T
Strain at Transverse Tensile Strength, b-axis
GMS
Strain at Shear Strength, ab plane
XC
Longitudinal Compression Strength
XT
Longitudinal Tensile Strength
YC
Transverse Compression Strength, b-axis
YT
Transverse Tensile Strength, b-axis
SC
Shear Strength, ab plane
See Also: • LS-DYNA Keyword User’s Manual
102 Materials
MAT_COMPOSITE_FAILURE_SHELL_MODEL Defines the properties of a composite material with failure properties (for shell elements only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus, Longitudinal Direction
EB
Young’s Modulus, Transverse Direction
EC
Young’s Modulus, Normal Direction
PRBA, PRCA< PRCB
Poisson’s Ratio in ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in ab, bc and ca directions
KF
Bulk Modulus of failed material
Materials 103 Materials
Field AOPT
Comments 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
MAFLAG
Material Axes Flag (NOT active for shells)
XP
X-coordinate of point p for AOPT=1 and 4
YP
Y-coordinate of point p for AOPT=1 and 4
ZP
Z-coordinate of point p for AOPT=1and 4
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3, and 4
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
TSIZE
Time step size for Automatic Element Deletion
ALP
Nonlinear stress parameter
SOFT
Softening Reduction Factor in Crashfront
FBRT
Softening of fiber Tensile Strength
SR
Reduction Factor
SF
Softening Factor
XC
Longitudinal Compression Strength
XT
Longitudinal Tensile Strength
YC
Transverse Compression Strength, b-axis
YT
Transverse Tensile Strength, b-axis
SC
Shear Strength, ab plane
See Also: • LS-DYNA Keyword User’s Manual
104 Materials
MAT_COMPOSITE_FAILURE_SOLID_MODEL Defines the properties of a composite material with failure properties (for solid elements only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus, Longitudinal Direction
EB
Young’s Modulus, Transverse Direction
EC
Young’s Modulus, Normal Direction
PRBA, PRCA< PRCB
Poisson’s Ratio in ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in ab, bc and ca directions
KF
Bulk Modulus of failed material
Materials 105 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
MAFLAG
Material Axes Change Flag 1: Default 2: Switch Axes a and b 3: Switch Axes a and c
XP
X-coordinate of point p for AOPT=1 and 4
YP
Y-coordinate of point p for AOPT=1 and 4
ZP
Z-coordinate of point p for AOPT=1and 4
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3, and 4
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
SBA
In Plane Shear Strength
SCA
Transverse Shear Strength
SCB
Transverse Shear Strength
XXC
Longitudinal Compression Strength, x-axis
YYC
Transverse Compression Strength, b-axis
106 Materials
Field
Comments
ZZC
Normal Compression Strength, c-axis
XXT
Longitudinal Tensile Strength, x-axis
YYT
Transverse Tensile Strength, b-axis
ZZT
Normal Tensile Strength, c-axis
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_WITH_VISCOSITY Simulates the forming of glass products at high temperatures.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
Materials 107 Materials
Field RO
Comments Mass Density of the material
V0 A, B, C
Viscosity coefficients
LCID
Load Curve Id defining factor for viscosity vs. temperature
PRi Ti
Temperatures
Vi
Corresponding Viscosity coefficients
Ei
Corresponding Young’s moduli coefficients
ALPHAi
Corresponding thermal expansion coefficients
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_WITH_VISCOSITY_CURVE Simulates the forming of glass products at high temperatures.Load curves are used to represent the temperature dependence of Poisson’s ratio, Young’s modulus, the coefficient of thermal expansion, and the viscosity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
V0
108 Materials
Field
Comments
A, B, C
Viscosity coefficients
LCID
Load Curve Id defining factor for viscosity vs. temperature
PR_LC
Load curve defining Poisson’s ratio as a function of temperature
YM_LC
Load curve defining Young’s modulus as a function of temperature
A_LC
Load curve defining the coefficient of thermal expansion as a function of temperature
V_LC
Load curve defining the viscosity as a function of temperature
V_LOG
Falg for the form of V_LC. If V_LOg =1, the value specified in V_LC is the natural logarithm of the viscosity. If V_LOg =0, the value is the viscosity.
See Also: • LS-DYNA Keyword User’s Manual MAT_KELVIN-MAXWELL_VISCOELASTIC A classic Kelvin-Maxwell material model for modeling viscoelastic bodies, like foams.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
BULK
Bulk Modulus (elastic)
GO
Short time Shear Modulus
GI
Long time Shear Modulus
DC
Maxwell decay constant or Kelvin relaxation constant
Materials 109 Materials
Field FO
Comments Formulation option 0: Maxwell 1: Kelvin
SO
Strain output option 0: Maximum principal Strain occurring during the calculation 1: Maximum magnitude of principal Strain occurring during the calculation 2: Maximum Effective Strain occurring during the calculation
See Also: • LS-DYNA Keyword User’s Manual MAT_VISCOUS_FOAM A material to represent the Confor Foam on the ribs of EuroSID side impact dummy (valid only for solid elements under compressive load).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E1
Initial Young’s Modulus
N1
Exponent in power law for Young’s Modulus
V2
Viscous Coefficient
E2
Elastic Modulus for viscosity
110 Materials
Field
Comments
N2
Exponent in power law for viscosity
PR
Poisson’s Ratio
See Also: • LS-DYNA Keyword User’s Manual MAT_CRUSHABLE_FOAM A material model for modeling crushable foam with optional damping and tension cutoff.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
LCID
Load Curve Id defining Yield Stress vs. Volumetric Strain
TSC
Tensile Stress Cutoff
DAMP
Rate sensitivity via damping coefficient
See Also: • LS-DYNA Keyword User’s Manual
Materials 111 Materials
MAT_RATE_SENSITIVE_POWERLAW_PLASTICITY A strain rate sensitive elasto-plastic material model with a power law hardening.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
K
Material Constant
M
Strain Hardening Coefficient
N
Strain Rate Sensitivity Coefficient
E0
Initial Strain Rate
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: ViscoPlastic Formulation
EPSO
Factor to Normalize Strain (Time Units) 1: Seconds 1e-006 : Milliseconds 1e-006 : Microseconds
112 Materials
Field
Comments
LCID_K
Load Curve Id defining material constant K vs. Effective Plastic Strain
LCID_M
Load Curve Id defining material constant M vs. Effective Plastic Strain
LCID_N
Load Curve Id defining material constant N vs. Effective Plastic Strain
See Also: • LS-DYNA Keyword User’s Manual MAT_MODIFIED_ZERILLI_ARMSTRONG A rate and temperature sensitive plasticity material model, sometimes used in ordinance design calculations.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
E0
Factor to normalize strain rate
N
Exponent for bcc metal
TROOM
Room Temperature
PC
Pressure Cutoff
Materials 113 Materials
Field SPALL
Comments Spall Type 1: Minimum Pressure Limit 2: Maximum Principal Stress 3: Minimum Pressure Cutoff
Ci
Coefficients for flow stress
EFAIL
Failure Strain for Erosion
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: ViscoPlastic Formulation
Bi
Coefficients for polynomial representation of temperature dependency of flow stress yield
Gi
Coefficient for defining Heat Capacity and temperature dependency of Heat Capacity
BULK
Bulk Modulus (for shell elements only)
See Also: • LS-DYNA Keyword User’s Manual
114 Materials
MAT_LINEAR_ELASTIC_DISCRETE_BEAM A material model for linear elastic beams by using six springs each acting along one of its six degrees of freedom. The two nodes that define the beam can be coincident to give a zero length beam, or offset to give a finite length beam.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TKR, TKS, TKT
Translational Stiffness along local ar-, s-, and t- axes respectively
RKR, RKS, RKT
Rotational Stiffness about local r-, s-, and t- axes respectively
TDR, TDS, TDT
Translational viscous damping along local r-, s-, and t- axes respectively
RDR, RDS, RDT
Rotational viscous damping about local r-, s-, and t- axes respectively
FOR, FOS, FOT
Pre-load forces in r-, s- and t-directions repectively (optional)
MOR, MOS, MOT
Pre-load moments in r-, s- and t-directions repectively (optional)
See Also: • LS-DYNA Keyword User’s Manual
Materials 115 Materials
MAT_NONLINEAR_ELASTIC_DISCRETE_BEAM A material model for nonlinear elastic and nonlinear viscous beams by using six springs each acting along one of its six degrees of freedom. The two nodes that define the beam can be coincident to give a zero length beam, or offset to give a finite length beam.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
LCIDTR, LCIDTS, LCIDTT
Load Curve Id defining Translational Force along the r-, s-, and t- axes vs. Translational Displacement
LCIDRR, LCIDRS, LCIDRT
Load Curve Id defining Rotational Moment about the r-, s-, and t- axes vs. Rotational Displacement
LCIDTDR, LCIDTDS, LCIDTDT
Load Curve Id defining Translational Damping Force along the r-, s-, and t- axes vs. Translational Velocity
LCIDRDR, LCIDRDS, LCIDRDT
Load Curve Id defining Rotational Damping Force the r-, s-, and t- axes axis vs. Rotational Velocity
FOR, FOS, FOT
Pre-load forces in r-, s- and t-directions repectively (optional)
MOR, MOS, MOT
Pre-load moments in r-, s- and t-directions repectively (optional)
See Also: • LS-DYNA Keyword User’s Manual
116 Materials
MAT_NONLINEAR_PLASTIC_DISCRETE_BEAM A a material model for nonlinear elastoplastic, linear viscous behavior of beams by using six springs each acting along one of its six degrees of freedom. The two nodes that define the beam can be coincident to give a zero length beam, or offset to give a finite length beam.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TKR, TKS, TKT
Translational Stiffness along local r-, s-, and t- axes respectively
RKR, RKS, RKT
Rotational Stiffness about local r-, s-, and t- axes respectively
TDR, TDS, TDT
Translational viscous damping along local r-, s-, and t- axes respectively
RDR, RDS, RDT
Rotational viscous damping about local r-, s-, and t- axes respectively
LCPDR, LCPDS, LCPDT
Load Curve Id for Yield Force vs. Plastic Displacement along local r-, s-, and t- axes respectively
LCPMR, LCPMS, LCPMT
Load Curve Id for Yield Moment vs. Plastic Rotation about local r-, s-, and t- axes respectively
Materials 117 Materials
Field
Comments
FFAILR, FAILS, FAILT
Failure Parameters corresponding to Force Fr, Fs, Ft
MFAILR, MFAILS, MFAILT
Failure Parameters corresponding to Moment Mr, Ms, Mt
UFAILR, UFAILS, UFAILT
Failure Parameters corresponding to Displacement Ur, Us, Ut
TFAILR, TFAILS, TFAILT
Failure Parameters corresponding to Rotation θr, θs, θt
FOR, FOS, FOT
Pre-load forces in r-, s- and t-directions repectively (optional)
MOR, MOS, MOT
Pre-load moments in r-, s- and t-directions repectively (optional)
See Also: • LS-DYNA Keyword User’s Manual MAT_SID_DAMPER_DISCRETE_BEAM A material model for side impact dummy, using a damper that is not adequately taken care of by the nonlinear force versus relative velocity curves.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
118 Materials
Field
Comments
RO
Mass Density of the material
ST
Piston Stroke
D
Piston Diameter
R
Orifice Radius
H
Orifice Controller Position
K
Damping Constant
C
Discharge Coefficient
C3
Coefficient for fluid inertia term
STF
Stiffness Coefficient (piston bottom out)
RHOF
Fluid Density
C1
Coefficient of linear velocity term
C2
Coefficient of quadratic velocity term
LCIDF
Load Curve Id defining Force vs. Piston Displacement
LCIDD
Load Curve Id defining Damping Coefficient vs. Piston Displacement
S0
Initial Displacement
NUM_RFS
Number of Orifice Location
ORFLOCi
Orifice Location of the i-th orifice, relative to the fix end
ORFRADi
Orifice Radius of the i-th orifice
SFi
Scale factor on calculated force for the i-th orifice
DCi
Linear viscous damping coefficient (after damper bottoms out in tension or compression) for the i-th orifice
See Also: • LS-DYNA Keyword User’s Manual
Materials 119 Materials
MAT_HYDRAULIC_GAS_DAMPER_DISCRETE_BEAM A special element that represents a combined hydraulic and gas-filled damper with a variable orifice coefficient. This material can only be used as a discrete beam element.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
C0
Length of Gas Column
N
Adiabatic constant
P0
Initial gas Pressure
PA
Atmospheric Pressure
AP
Piston Cross-Section Area
KH
Hydraulic Constant
LCID
Load Curve Id Defining Orifice Area vs. Element Deletion
FR
Return factor on orifice force
SCLF
Scale factor on Force
CLEAR
Clearance
See Also: • LS-DYNA Keyword User’s Manual
120 Materials
MAT_CONCRETE_DAMAGE A material model for analyzing buried steel reinforced concrete structure with impulsive loading.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGF
Maximum principal Stress at Failure
A0, A0Y
Cohesion and Cohesion for Yield
Materials 121 Materials
Field
Comments
A1, A2
Pressure Hardening Coefficients
A1Y, A2Y
Pressure Hardening Coefficients for yield limit
A1F, A2F
Pressure Hardening Coefficients Failed Material)
B1
Damage Scaling Factor
B2
Damage Scaling Facto for uniaxial tensile path
B3
Damage Scaling Facto for triaxial tensile path
PER
Percent Reinforcement
ER
Young’s Modulus for Reinforcement
PRR
Poisson’s Ration for Reinforcement
SIGY
Initial Yield Stress
ETAN
Tangent Modulus/Plastic hardening Modulus
LCP
Load Curve Id giving rate sensitivity for principal material
LCR
Load Curve Id giving rate sensitivity for reinforcement
LAMBDAi
Tabulated Damage functions
ETAi
Tabulated Scale Factors
See Also: • LS-DYNA Keyword User’s Manual
122 Materials
MAT_LOW_DENSITY_VISCOUS_FOAM A material model for low density urethane foam with high compressibility, and with rate sensitivity characterized by a relaxation curve.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
LCID
Load Curve Id for nominal Stress vs. Strain
TC
Tension Cutoff Stress
HU
Hysteretic Unloading Factor between 0 to 1
BETA
Decay constant to model creep in unloading
DAMP
Viscous coefficient
SHAPE
Shape factor for unloading
FAIL
Failure Option after Cutoff Stress 1: Tensile stress remains at cutoff value 2: Tensile stress is reset to zero
Materials 123 Materials
Field BVFLAG
Comments Bulk Viscosity activation Flag 0: No 1: Active
KCON
Stiffness coefficient for contact interface stiffness
LCID2
Load Curve Id of relaxation curve
BSTART
Fit Parameter
TRAMP
Optional ramp time for loading
NV
Number of terms in fit
NUM_RFS
Number of viscoelastic constants
GI1
Optional relaxation modulus for rate effect
BETAI1
Optional decay constant
REF
Use Reference Geometry to initialize stress tensor 0: Off 1: On
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_SPRING_DISCRETE_BEAM A model for elastic springs with damping to be combined and represented with a discrete beam element.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
124 Materials
Field
Comments
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
K
Elastic loading and unloading stiffness
F0
Optional initial force
D
Optional viscous damping coefficient
CDF
Compressive displacement at failure
TDF
Tensile displacement at failure
FLCID
Load Curve Id defining Yield Force vs. Deflection for nonlinear behavior
HLCID
Load Curve Id defining Force vs. Relative Velocity for nonlinear behavior
Ci
Damping Coefficients
DLE
Scale factor for time unit
GLCID
Load Curve Id defining Scale Factor vs. Deflection for Load Curve Id (HLCID)
See Also: • LS-DYNA Keyword User’s Manual MAT_BILKHU/DUBOIS_FOAM A material model to simulate isotropic crushable foams using uniaxial and triaxial test data.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
Materials 125 Materials
Field
Comments
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
YM
Young’s Modulus
LCPY
Load Curve Id defining Yield Pressure vs. Volumetric Strain
LCUYS
Load Curve Id defining uniaxial Yield Stress vs. Volumetric Strain
VC
Viscous Damping Coefficient
PC
Pressure Cutoff
VPC
Variable Pressure Cutoff as a fraction of pressure yield value
TC
Tension Cutoff for uniaxial tensile stress
VTC
Variable Tension Cutoff as a fraction of uniaxial compressive yield strength
LCRATE
Load Curve Id defining Scale Factor for the previous yield curves, dependent upon the volumetric strain vs. Volumetric plastic Strain
PR
Poisson coefficient applying to both elastic and plastic deformations
KCON
Stiffness coefficient for contact interface stiffness. If undefined, one third of Young’s Modulus (YM) is used..
ISFLG
Tensile response flag (active only if negative abscissa are present in the load curve LCUYS). .EQ. 0: load curve abscissa in tensile region correspond to volumetric strain. .EQ. 1: load curve abscissa in tensile region correspond to effective strain.
See Also: • LS-DYNA Keyword User’s Manual
126 Materials
MAT_GENERAL_VISCOELASTIC A general viscoelastic Maxwell model used for modeling dense continuum rubber and solid explosives.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
BULK
Elastic Bulk Modulus
PCF
Tensile Pressure elimination flag (for solid elements only) 1: yes (Tensile Pressure reset to zero) 0: no (Tensile Pressure NOT reset to zero)
EF
Elastic Flag 1: Elastic layer 0: Viscoelastic layer
LCID
Load Curve Id for deviatoric behavior
NT
Number of terms in shear fit
BSTART
Parameter for resetting the exponents in the Relaxation Curve
TRAMP
Optional Time ramp for loading
LCIDK
Load Curve ID defining the bulk behavior
Materials 127 Materials
Field
Comments
NTK
Number of terms in bulk
BSTARTK
Fit Parameter for bulk
TRAMPK
Optional ramp time for bulk loading
NUM_RFS
number of viscoelastic constants
GIi
Optional shear relaxation modulus for the i-th term
BETAIi
Optional shear Decay Constant for the i-th term
KIi
Optional bulk Relaxation Modulus for the i-th term
BETAKIi
Optional bulk Decay Constant for the i-th term
See Also: • LS-DYNA Keyword User’s Manual MAT_HYPERELASTIC_RUBBER A general hyperelastic rubber material model, combined optionally with linear viscoelasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
128 Materials
Field
Comments
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
PR
Poisson’s Ratio
N
Constants to solve for 1: Solve for C10, C01 2: Solve for C10, C01, C11, C20, C02 3: Solve for All constants (C10, C01, C11, C20, C02, and C30)
NV
Number of Prony series terms in fit
G
Shear Modulus
SIGF
Limit stress for frequency independent, frictional, Damping
SGL
Specimen gauge length
SW
Specimen Width
ST
Specimen Thickness
LCID1
Load Curve Id defining Force vs. Actual Change in gauge Length
DATA
Type of experimental data 0:Uniaxial
LCID2
Load Curve Id of relaxation curve
BSTART
Fit Parameter
TRAMP
Optional ramp time for loading
Ci
Material Constants
NUM_RFS
Number of viscoelastic constants
GIi
Optional Shear Relaxation Modulus for the i-th term
BETAIi
Optional Decay Constants for the i-th term
See Also: • LS-DYNA Keyword User’s Manual
Materials 129 Materials
MAT_OGDEN_RUBBER An Ogden rubber material model, combined optionally with linear viscoelasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
PR
Poisson’s Ratio
N
Order to fit the Ogden model
NV
Number of Prony series terms in fit
G
Shear Modulus
SIGF
Limit stress for frequency independent, frictional, Damping
SGL
Specimen gauge length
SW
Specimen Width
ST
Specimen Thickness
130 Materials
Field
Comments
LCID1
Load Curve Id defining Force vs. Actual Change in Length
DATA
Type of experimental data 1:Uniaxial 2:Biaxial
LCID2
Load Curve Id of relaxation curve
BSTART
Fit Parameter
TRAMP
Optional ramp time for loading
MUi
i-th Shear Modulus
ALPHAi
i-th Exponent
NUM_RFS
Number of viscoelastic constants
GIi
i-th Optional Shear Relaxation Modulus
BETAIi
i-th Optional Decay Constant
See Also: • LS-DYNA Keyword User’s Manual MAT_SOIL_CONCRETE An efficient soil and concrete material model.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
Materials 131 Materials
Field
Comments
K
Bulk Modulus
LCPV
Load Curve Id defining Pressure vs. Volumetric Strain
LCYP
Load Curve Id defining von Mises Stress vs. Pressure
LCFP
Load Curve Id defining Plastic Strain at which fracture starts vs. Pressure
LCRP
Load Curve Id defining Plastic Strain at which residual strength is released vs. Pressure
PC
Pressure Cutoff
OUT
Output option for plastic strain 0: Volumetric 1: Deviatoric
B
Residual strength factor after cracking
FAIL
Failure flag 0: No 1: Element Erodes when Pressure reached failure pressure 2: No tension in element when Pressure reached failure pressure
See Also: • LS-DYNA Keyword User’s Manual
132 Materials
MAT_HYSTERETIC_SOIL A nested surface material model with five superimposed layers of elasto-perfectly plastic material, each with its own elastic moduli and yield values.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K0
Bulk Modulus
P0
Pressure Cutoff
B
Exponent for pressure sensitive moduli
A0, A1, A2
Yield Function Constants
DF
Damping Factor
RP
Reference Pressure
LCID
Load Curve Id defining Shear Stress vs. Shear Strain
SCLF
Scale Factor o apply on shear stress in LCID
DIL_A
Dilation Parameter A
DIL_B
Dilation Parameter B
DIL_C
Dilation Parameter C
DIL_D
Dilation Parameter D
Materials 133 Materials
Field
Comments
GAMi
Shear Strains (if LCID is zero)
PINIT
Pressure sensitivity flag: .EQ. 0: Use current pressure .EQ. 1: Use pressure from initial stress state .EQ. 2: Use initial “plane stress”pressure .EQ. 3: Use compressive initial vertical stress
TAUi
Shear Stresses (if LCID is zero)
See Also: • LS-DYNA Keyword User’s Manual MAT_RAMBERG_OSGOOD A simple material model of shear behavior, and can be used for seismic analysis.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
GAMY
Reference Shear Strain
TAUY
Reference Shear Stress
ALPHA
Stress coefficient
R
Stress exponent
BULK
Elastic Bulk Modulus
134 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_PLASTICITY_WITH_DAMAGE An elasto-visco-plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency. Damage, in this model, is considered before rupture occurs.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
EPPF
Plastic Strain, at which material softening begins
TDEL
Minimum time step size for Automatic Element Deletion
C, P
Strain Rate Parameters
LCSS
Load Curve Id defining Effective Stress vs. Effective Plastic Strain
LCSR
Load Curve Id defining Strain Rate Scaling Effect on Yield Stress
EPPFR
Plastic Strain at which material ruptures
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
Materials 135 Materials
Field
Comments
LCDM
Load Curve Id defining nonlinear damage curve
NUMINT
No. of through thickness integration points which must fail before the element is deleted
See Also: • LS-DYNA Keyword User’s Manual MAT_PLASTICITY_WITH DAMAGE_ORTHO_RCDC An elasto-visco-plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency. This includes an orthotropic damage model (only for shell elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
EPPF
Plastic Strain, at which material softening begins
TDEL
Minimum time step size for Automatic Element Deletion
136 Materials
Field
Comments
C, P
Strain Rate Parameter
LCSS
Load Curve Id defining Effective Stress vs. Effective Plastic Strain
LCSR
Load Curve Id defining Strain Rate Scaling Effect on Yield Stress
EPPFR
Plastic Strain at which material ruptures
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
NUMINT
No. of through thickness integration points which must fail before the element is deleted
LCDM
Load Curve Id defining nonlinear damage curve
ALPHA
Parameter α
BETA
Parameter β
GAMMA
Parameter γ
D0
Parameter D0
B
Parameter b
LAMDA
Parameter λ
DS
Parameter Ds
L
Optional characteristic element length for this material.
See Also: • LS-DYNA Keyword User’s Manual
Materials 137 Materials
MAT_FU_CHANG_FOAM A material such as low and medium density foams, for hysteric unloading behaviors. Rate effects can be included in this material model.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
ED
Young’s Relaxation Modulus for rate effect
TC
Tension Cutoff Stress
FAIL
Failure option after Cutoff Stress is reached 0: Tensile Stress Remains at cutoff 1: Tensile Stress Resets to Zero
DAMP
Viscous Coefficient
TBID
Table Id for nominal Stress vs. Strain
138 Materials
Field BVFLAG
Comments Bulk Viscosity activation Flag 0: No 1: Active
SFLAG
Strain Rate Flag 0: True strain 1: Engineering strain
RFLAG
Strain Rate evaluation flag 0 : First principal direction 1 : Principal strain rates for each principal direction 2: Volumetric strain rate
TFLAG
Tensile Stress Evaluation Flag 0: Linear 1: Input via Load Curves with the tensile response corresponding to negative values of stress and strain
PVID
Load Curve Id defining Pressure vs. Volumetric Strain
SRAF
Strain Rate averaging flag 0: Weighted running average 1: Average of the last twelve values
REF
User reference geometry to initialize the stress tensor.: .EQ. 0: OFF .EQ. 1: ON
HU
Hysteric unloading factor between 0 and 1 (default = 1, i.e. no energy dissipation).
D0, N0, C0, Ni, Ci
Material Constants
AIJ, SIJ
Material Constants
MINR
Minimum strain rate of interest
MAXR
Maximum strain rate of interest
SHAPE
Shape factor for unloading. Active for nonzero values of the hysteric unloading factor HU.
Materials 139 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_WINFRITH_CONCRETE A smeared crack, smeared rebar, material model (only for the 8-noded single integration point continuum element).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TM
Tangent Modulus of Concrete
PR
Poisson’s Ratio
UCS
Uniaxial Compression Strength
UTS
Uniaxial Tensile Strength
FE
Depends on value for RATE If RATE = 0, FE is Fracture Energy per unit area in opening crack If RATE = 1, FE is crack width at which crack-normal tensile stress becomes zero
ASIZE
Aggregate size (radius)
E
Young’s Modulus for rebar
YS
Yield Stress for rebar
140 Materials
Field
Comments
EH
Hardening Modulus for rebar
UELONG
Ultimate elongation before rebar fails
RATE
Rate effects Flag 0: Included (MAT_0 84) 1: Turned off (MAT_0 85)
CONM
Factor to convert model mass units to kg
CONL
Factor to convert model length units to meters (if CONM .GT. 0)
CONT
Factor to convert model time units to seconds
LCID
Defining Pressure vs. Volumetric Strain
See Also: • LS-DYNA Keyword User’s Manual
Materials 141 Materials
MAT_WINFRITH_CONCRETE_REINFORCEMENT A rebar reinforcement material model (material type 84). Reinforcement quantity is defined as the ratio of the cross-sectional area of steel, relative to the cross-sectioanl area of concrete in the element (or layer).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TM
Tangent Modulus of Concrete
PR
Poisson’s Ratio
UCS
Uniaxial Compression Strength
UTS
Uniaxial Tensile Strength
FE
Depends on value for RATE If RATE = 0, FE is Fracture Energy per unit area in opening crack If RATE = 1, FE is crack width at which crack-normal tensile stress becomes zero
142 Materials
Field
Comments
ASIZE
Aggregate size (radius)
E
Young’s Modulus for rebar
YS
Yield Stress for rebar
EH
Hardening Modulus for rebar
UELONG
Ultimate elongation before rebar fails
RATE
Rate effects Flag 0: Included (MAT_0 84) 1: Turned off (MAT_0 85)
CONM
Factor to convert model mass units to kg
CONL
Factor to convert model length units to meters (if CONM .GT. 0)
CONT
Factor to convert model time units to seconds
LCID
Defining Pressure vs. Volumetric Strain
EID1
First element Id in group
EID2
Last element Id in group
INC
Element increment for genaration
XR
X-reinforcement quantity (for bars running parallel to global x-axis)
YR
Y-reinforcement quantity (for bars running parallel to global y-axis)
ZR
Z-reinforcement quantity (for bars running parallel to global z-axis)
PID
Part Id of reinforced elements
AXIS
Axis normal to layer: .EQ. 1: A and B are parallel to global Y and Z, respectively .EQ. 2 A and B are parallel to global X and Z, respectively .EQ. 3: A and B are parallel to global X and Y, respectively
COOR
Coordinate location of layer (X-coordinate if AXIS = 1, Y-Coordinate if AXIS = 2, Z-Coordinate if AXIS = 3)
RQA
Reinforcement quantity (A)
RQB
Reinforcement quantity (B)
Materials 143 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_ORTHOTROPIC_VISCOELASTIC A viscoelastic material model (only for shell elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus in Longitudinal Direction
EB
Young’s Modulus in Transverse Direction
EC
Young’s Modulus in Normal Direction
VF
Volume fraction for viscoelastic material
K
Elastic Bulk Modulus
G0
Short time Shear Modulus
GINF
Long time Shear Modulus
BETA
Decay Constant
144 Materials
Field
Comments
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in the ab, bc and ca directions
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
MANGLE
Material Angle (Degrees), for AOPT=3
blank1, blank2, blank3
Blank Fields
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual
Materials 145 Materials
MAT_CELLULAR_RUBBER A material model for a cellular rubber with confined air pressure, combined with linear viscoelasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
PR
Poisson’s Ratio
N
Order or fit
SGL
Specimen Gauge Length
SW
Specimen Width
ST
Specimen Thickness
LCID
Load Curve Id defining the Force vs. Actual Change in gauge Length
C10, C01, C11, C20, C02
Material Constants
P0
Initial Air Pressure
PHI
Ratio of cellular rubber to rubber density
IVS
Initial Volumetric Strain
G
Optional shear relaxation modulus, G, for rate effects
BETA
Optional Decay Constant
146 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_MTS This MTS material model, developed by Maudlin, Davidson, and Henninger [1990], is used for applications involving high pressures, large strains, and high strain rates. This model uses dislocation mechanics and provides an understanding of the plastic deformation process in ductile materials.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
SIGA
Dislocation interaction with long-range barriers
SIGI
Dislocation interaction with interstitial atoms
SIGS
Dislocation interaction with solute atoms
SIG0
NOT used
BULK
Bulk Modulus (for shell elements)
HF0, HF1, HF2
Dislocation generation material constants
SIGSO
Saturation Threshold stress at 0 degrees K
Materials 147 Materials
Field
Comments
EDOTSO, EDOTO, EDOTI, EDOTS
Reference Strain rates
BURG
Magnitude of Burgers vector
CAPA
Material Constant, A
BOLTZ
Boltzmann’s constant, k
SM0, SM1, SM2
Shear Modulus Constants
G0, GOI, GOS
Normalized activation energies
PINV, QINV, PINVI, QINVI, PINVS., QINVS., ALPHA
Material Constants
RHOCPR
Product of density and specific heat
TEMPRF
Initial Element Temperature
EPSO
Factor to normalize strain rate
See Also: • LS-DYNA Keyword User’s Manual MAT_PLASTICITY_POLYMER An elasto-plastic material model with arbitrary stress versus strain curve, and arbitrary strain rate dependency.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
148 Materials
Field
Comments
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
PR
Poisson’s Ratio
C, P
Strain Rate Parameters
LCSS
Load Curve Id defining Effective Stress vs. Total Effective Strain
LCSR
Load Curve Id defining Strain Rate Scaling effect on Yield Stress
EFTX
Failure Flag 0: Failure determined by Maximum tensile strain 1: Failure determined only by tensile strain in local x direction 2: Failure determined only by tensile strain in local y direction
DAMP
Stiffness proportional damping ratio
RATEFAC
Filtering factor for strain rate effect
LCFAIL
Load Curve Id defining variation of Failure strain with Strain rate
See Also: • LS-DYNA Keyword User’s Manual MAT_ACOUSTIC Defines the properties of materials used to track low pressure waves in acoustic media, like air or water (only for acoustic pressure elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
Materials 149 Materials
Field
Comments
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
C
Sound Speed
BETA
Damping Factor
CF
Cavitation Flag 0: Off 1: On
ATMOS
Atmospheric Pressure
GRAV
Gravitational Acceleration constant
XP, YP, ZP
Coordinates of free surface point
XN, YN, ZN
Direction cosines of free surface normal vector
See Also: • LS-DYNA Keyword User’s Manual
150 Materials
MAT_SOFT_TISSUE Defines a transversely isotropic hyperelastic material that represents biological soft tissue such as ligaments, tendons, and fascia.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Ci
Hyperelastic Coefficients
XK
Bulk Modulus
XLAM
Stretch ratio at which fibers are straightened
FANG
Fiber angle in local shell coordinate system (shell elements only)
XLAMO
Initial fiber stretch
FAILSF
stretch ratio for ligament fibers at failure (shell elements only). If zero, failure is not considered.
FAILSM
stretch ratio for surrounding matrix material at failure (shell elements only). If zero, failure is not considered.
Materials 151 Materials
Field
Comments
FAILSHR
Shear strain at failure of a material point (shell elements only). If zero, failure is not considered. This failure value is independent of FAILSF and FAILSM.
AOPT
0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
AX, AY, AZ
Components of first material axis point/vector
BX, BY, BZ
Components of second material axis point/vector
LAX, LAY, LAZ
Component of fiber orientation vector (Brick elements only)
MACF
Material axes change flag for brick element: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
See Also: • LS-DYNA Keyword User’s Manual
152 Materials
MAT_SOFT_TISSUE_VISCO A transversely isotropic hyperelastic material model that represents biological soft tissue such as ligaments, tendons, and fascia. This model has a viscoelastic option activating a six-term Prony series kernel for the relaxation function.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Ci
Hyperelastic Coefficients
XK
Bulk Modulus
XLAM
Stretch ratio at which fibers are straightened
FANG
Fiber angle in local shell coordinate system (shell elements only)
XLAMO
Initial fiber stretch
Materials 153 Materials
Field AOPT
Comments 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
AX, AY, AZ
Components of first material axis point/vector
BX, BY, BZ
Components of second material axis point/vector
LAX, LAY, LAZ
Component of fiber orientation vector (Brick elements only)
Si
Spectral strengths for prony series relaxation kernel
Ti
Characteristic time for prony series relaxation kernel
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_6DOF_SPRING_DISCRETE_BEAM A material model for simulating the effects of nonlinear elastic and nonlinear viscous beams using six springs each acting along one of it six degrees-of-freedom.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TPIDR
Part Id governing the Translational motion in the local r direction (If zero, no force is computed in this direction)
154 Materials
Field
Comments
TPIDS
Part Id governing the Translational motion in the local s direction (If zero, no force is computed in this direction)
TPIDT
Part Id governing the Translational motion in the local t direction (If zero, no force is computed in this direction)
RPIDR
Part Id governing the Rotational motion about the local r direction (If zero, no moment is computed in this direction)
RPIDS
Part Id governing the Rotational motion about the local s direction (If zero, no moment is computed in this direction)
RPIDT
Part Id governing the Rotational motion about the local t direction (If zero, no moment is computed in this direction)
See Also: • LS-DYNA Keyword User’s Manual MAT_INELASTIC_SPRING_DISCRETE_BEAM A material model for elastoplastic springs, with damping to be represented with discrete beam elements. A yield force versus deflection is used which can vary in tension and compression.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Elastic Loading/Unloading Stiffness
F0
Optional initial force
D
Optional viscous damping coefficient
Materials 155 Materials
Field
Comments
CDF
Compressive displacement at failure
TDF
Tensile Displacement at failure
FLCID
Load Curve Id defining Yield Force vs. Plastic Displacement
HLCID
Load Curve Id defining Force vs. Relative Velocity
C1, C2
Damping Coefficients
DLE
Scale Factor for time unit
GLCID
Load Curve Id defining a Scale Factor vs. Deflection for Load Curve Id, HLCID
See Also: • LS-DYNA Keyword User’s Manual MAT_INELASTIC_6DOF_SPRING_DISCRETE_BEAM A material model for nonlinear inelastic and nonlinear viscous beams using six springs each acting along one of it six degrees-of-freedom.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TPIDR
Part Id governing the Translational motion in the local r direction (If zero, no force is computed in this direction)
TPIDS
Part Id governing the Translational motion in the local s direction (If zero, no force is computed in this direction)
TPIDT
Part Id governing the Translational motion in the local t direction (If zero, no force is computed in this direction)
156 Materials
Field
Comments
RPIDR
Part Id governing the Rotational motion about the local r direction (If zero, no moment is computed in this direction)
RPIDS
Part Id governing the Rotational motion about the local s direction (If zero, no moment is computed in this direction)
RPIDT
Part Id governing the Rotational motion about the local t direction (If zero, no moment is computed in this direction)
See Also: • LS-DYNA Keyword User’s Manual MAT_BRITTLE_DAMAGE A material model with anisotropic brittle damage characteristics, used mainly for concrete but can be applied for a variety of brittle materials.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
TLIMIT
Tensile Limit
SLIMIT
Shear Limit
FTOUGH
Fracture Toughness
SRETEN
Shear Retention
VISC
Viscosity
Materials 157 Materials
Field
Comments
FRA_RF
Fraction of reinforcement in section
E_RF
Young’s Modulus of Reinforcement
YS_RF
Yield Stress of Reinforcement
EH_RF
Hardening Modulus of Reinforcement
FS_RF
Failure Strain of Reinforcement
SIGY
Compressive Yield Stress
See Also: • LS-DYNA Keyword User’s Manual MAT_GENERAL_JOINT_DISCRETE_BEAM Defines the properties of a general joint constraining any combination of degrees of freedom between two nodes.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
TR
Translational Constraint Code along r-axis 0: Free 1:Fixed
158 Materials
Field TS
Comments Translational Constraint Code along s-axis 0: Free 1:Fixed
TT
Translational Constraint Code along t-axis 0: Free 1:Fixed
RR
Rotational Constraint Code about r-axis 0: Free 1:Fixed
RS
Rotational Constraint Code about s-axis 0: Free 1:Fixed
RT
Rotational Constraint Code about t-axis 0: Free 1:Fixed
RPST
Penalty stiffness scale factor for translational constraints
RPSR
Penalty stiffness scale factor for rotational constraints
See Also: • LS-DYNA Keyword User’s Manual
Materials 159 Materials
MAT_SIMPLIFIED_JOHNSON_COOK A material model used for problems where the strain rates vary over a large range. In this model, thermal effect and damage are ignored and maximum stress is directly limited since thermal softening is not available.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
A, B, N, C
Parameters used in the Johnson-Cook flow stress equation
PSFAIL
Effective Plastic Strain at Failure
SIGMAX
Maximum Stress obtained from Work Hardening before rate effects are added
SIGSAT
Saturation Stress
EPSO
Effective Plastic Strain rate
See Also: • LS-DYNA Keyword User’s Manual
160 Materials
MAT_SIMPLIFIED_JOHNSON_COOK_ORTHO_DAMAGE Defines the properties of a material used for problems where the strain rates vary over a large range. Orthotropic damage is included as a means for treating failure in aluminum panels (only for shell elements with multiple through thickness integration points).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
EPPFR
Plastic Strain at which the material ruptures
LCDM
Load Curve Id defining nonlinear damage curve
NUMINT
No. of through thickness integration points which must fail before element is deleted
A, B, N, C
Parameters used in the Johnson-Cook flow stress equation
PSFAIL
Effective Plastic Strain at Failure
SIGMAX
Maximum Stress obtained from Work Hardening before rate effects are added
SIGSAT
Saturation Stress
EPSO
Effective Plastic Strain rate
Materials 161 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_SPOTWELD A material model for spotweld modeled with beam element type 9, and solid element type 1.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Initial Yield Stress
ET
Hardening Modulus
DT
Time Step Size for Mass Scaling
TFAIL
Failure Time (Ignored if value is zero)
EFAIL
Effective Plastic Strain at Failure
NRR
Axial force resultant NrrF (or Maximum Axial Stress σrrF) at failure
NRS
Force resultant NrsF (or Maximum Shear Stress τF) at failure
NRT
Force resultant NrtF at failure
MRR
Torsional moment resultant MrrF at failure
MSS
Moment resultant MssF at failure
MTT
Moment resultant MttF at failure
NF
No. of force vectors stored for filtering
162 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_SPOTWELD_DAMAGE-FAILURE A material model used in spotweld, modeled with beam element type 9, and solid element type 1. Damage parameters are also included in this model.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Initial Yield Stress
ET
Hardening Modulus
DT
Time Step Size for Mass Scaling
TFAIL
Failure Time (Ignored if value is zero)
EFAIL
Effective Plastic Strain at Failure
NRR
Axial force resultant NrrF (or Maximum Axial Stress σrrF) at failure
NRS
Force resultant NrsF (or Maximum Shear Stress τF) at failure
NRT
Force resultant NrtF at failure
MRR
Torsional moment resultant MrrF at failure
Materials 163 Materials
Field
Comments
MSS
Moment resultant MssF at failure
MTT
Moment resultant MttF at failure
NF
No. of force vectors stored for filtering
RS
Rupture Strain
OPT
Failure Option 0: Resultant based failure 1: Stress based failure computed from resultant (Toyota) 2: User subroutine to determine failure 3: Notch stress based failure (beam weld only) 4: Stress intensity factor at failure (beam weld only) 5: Structural stress at failure (beam weld only)
FVAL
Failure parameter: .EQ. 3: Notch stress value at failure (σKF) .EQ. 4: Stress intensity factor value at failure (KeqF) .EQ. 5: Structural stress value at failure (σSF) .EQ. 6: Number of cycles that that failure condition must be met to trigger beam deletion. .EQ. 9: Number of cycles that that failure condition must be met to trigger beam deletion. Note: Values of -2, -1, 0, 1, 2, 7 - Not used
TRUE_T
True weld thickness. This optional value is available for solid element failure by OPT = 0, 1, 7, or -2.
BETA
Damage model decay rate.
See Also: • LS-DYNA Keyword User’s Manual MAT_SPOTWELD_DAIMLERCHRYSLER A material model used in spotweld, modeled with solid element type 1, with type 6 hour glass control. Special Damage parameters are used in this model.
164 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
DT
Time Step Size for Mass Scaling
TFAIL
Failure Time (Ignored if value is zero)
EFAIL
Effective Plastic Strain at Failure
NF
Number of failure function evaluations stored for filtering by time averaging.
RS
Rupture Strain
TRUE_T
True weld thickness for hexahedron solid weld element.
CON_ID
Connection Id of *DEFINE_CONNECTION
See Also: • LS-DYNA Keyword User’s Manual
Materials 165 Materials
MAT_GEPLASTIC_SRATE_2000a Defines properties for the General Electric’s commercially available thermoplastics subjected to high strain rates. This model features variation of yield stress dependent upon strain rate, cavitation effects of rubber modified material, and automatic element deletion for either ductile or brittle materials.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
RATESF
Constant in plastic strain rate equation
EDOTO
Reference Strain Rate
ALPHA
Pressure Sensitive Factor
LCSS
Load Curve Id (or Table Id) for post Yield Stress behavior vs. Strain
LCFEPS
Load Curve Id for Plastic failure Strain vs. Strain Rate
LCFSIG
Load Curve Id for Maximum principal failure Stress vs. Strain Rate
LCE
Load Curve Id for Unloading Moduli vs. Plastic Strain
See Also: • LS-DYNA Keyword User’s Manual
166 Materials
MAT_HYPERBOLIC_SIN Defines properties for modeling materials with temperature and rate dependent plasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
T
Initial Temperature
HC
Heat Generation Coefficient
VP
Formulation for Rate Effects 0: Scale Yield Stress 1: Viscoplastic Formulation
ALPHA, N, A, Q, G
Material constitutive constants
EPSO
Effective plastic strain rate
See Also: • LS-DYNA Keyword User’s Manual
Materials 167 Materials
MAT_ANISOTROPIC_VISCOPLASTIC Defines an anisotropic viscoplastic material that is applied to either shell or brick elements. The material constants may be input directly, or by stress-strain data. If stress-strain data is provided, a least squares fit will be performed to determine the constants.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Initial Yield Stress
FLAG
Flag for material parameters
LCSS
Load Curve Id for Effective Stress vs. Effective Plastic Strain
168 Materials
Field ALPHA
Comments α distribution hardening: =0: Kinematic hardening = 1: Isotropic hardening
QRi, CRi
Isotropic Hardening Parameters
QXi, CXi
Kinematic Hardening Parameters
VK, VM
Viscous Material Parameters
R00/F
R00 for shell, or F for solid
R45/G
R45 for shell, or G for solid
R90/H
R90 for shell, or H for solid
L, M, N
Parameters (for solid elements only
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
FAIL
Failure flag: .LT. 0: user defined failure subroutine to determine failure. .EQ. 0: failure is not considered .GT. 0: Plastic strain to failure. When the plastic strain reaches this value, the element is deleted from calculation.
Materials 169 Materials
Field
Comments
NUMINT
Number of integration point which must fail before element is deleted.. If zero, all points must fail. This option applies to shell elements only.
MACF
Material axes change flag: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
XP, YP, ZPP
Coordinates of point p, for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
170 Materials
MAT_ANISOTROPIC_PLASTIC This anisotropic plastic material model is a simplified version of the MAT_ANISOTROPIC_VISCOPLASTIC model. This model applies to shell elements only.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Initial Yield Stress
LCSS
Load Curve Id for effective Stress vs. effective plastic Strain
QRi, CRi
Isotropic Hardening Parameters
QXi, CXi
Kinematic Hardening Parameters
R00/F
R00 for shell or F for solid
R45/G
R45 for shell or G for solid
R90/H
R90 for shell or H for solid
Materials 171 Materials
Field
Comments
S11, S22, S33, S12
Yield Stress in the x, y, z and xy direction, respectively
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
XP, YP, ZP
Coordinates of point p, for AOPT=1
Ai
Components of Vector a, for AOPT=2
Vi
Components of Vector v, for AOPT=3
Di
Components of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
172 Materials
MAT_DAMAGE_1 Defines properties for a continuum damage mechanics material model which includes anisotropy and viscoplasticity. This model is applied to shell, thick shell and brick elements.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Initial Yield Stress
LCSS
Load Curve Id for effective Stress vs. effective plastic Strain
LCDM
Load Curve Id defining nonlinear damage (for FLAG = -1)
Qi, Ci
Isotropic Hardening Parameters
EPSD
Damage Threshold, rd
Materials 173 Materials
Field
Comments
S
Damage Material Constant
EPSR
Plastic strain at which material ruptures
DC
Critical Damage valueDc
FLAG
Flag for Localization -1: Anisotropic damage 0: No calculation of localization due to damage 1: Flag those elements where local stabilization occurs
VK, VM
Viscous Material Parameter
R00/F
R00 for shell or F for solid
R45/G
R45 for shell or G for solid
R90/H
R90 for shell or H for solid
L, M, N
Parameters (for solid elements only
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
XP, YP, ZP
Coordinates of point p, for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
174 Materials
Field
Comments
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual MAT_DAMAGE_2 Defines properties for an elastic viscoplastic material model combined with the continuum damage mechanics. This model is applied to shell, thick shell and brick elements.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
FAIL
Failure flag =0: Failure due to plastic strain not considered > 0: Plastic strain to failure considered. When the plastic strain reaches this value, the element is deleted from calculation.
Materials 175 Materials
Field
Comments
TDEL
Minimum time step for Automatic Element Deletion
C, P
Strain Rate Parameters
LCSS
Load Curve Id defining effective Stress vs. effective plastic Strain
LCSR
Load Curve Id defining Strain Rate Scaling Effect on Yield Stress
EPSD
Damage Threshold, rd
S
Damage Material Constant
DC
Critical Damage valueDc
See Also: • LS-DYNA Keyword User’s Manual MAT_ELASTIC_VISCOPLASTIC_THERMAL Defines properties for an elastic viscoplastic material with thermal effects.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
176 Materials
Field
Comments
SIGY
Initial Yield Stress
ALPHA
Coefficient of thermal expansion
LCSS
Load Curve Id for effective Stress vs. effective plastic Strain
QRi, CRi
Isotropic Hardening Parameters
QXi, CXi
Kinematic Hardening Parameters
C, P
Viscous Material Parameters
LCE
Load Curve Id defining Young’s Modulus vs. Temperature
LCPR
Load Curve Id defining Poisson’s Ratio vs. Temperature
LCSIGY
Load Curve Id defining Initial Yield Stress vs. Temperature
LCR
Load Curve Id defining for Parameters QR1 and QR2 vs. Temperature
LCX
Load Curve Id defining for Parameters QX1 and QX2 vs. Temperature
LCALPH
Load Curve Id defining Coefficient of thermal expansion vs. Temperature
LCC
Load Curve Id defining scaling Viscous material parameter C vs. Temperature
LCP
Load Curve Id defining scaling Viscous material parameter P vs. Temperature
See Also: • LS-DYNA Keyword User’s Manual
Materials 177 Materials
MAT_JOHNSON_HOLMQUIST_CERAMICS Defines properties for a material used to model ceramics, glass and other brittle materials.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
A
Intact normalized strength parameter
B
Fractured normalized strength parameter
C
Strength Parameter (for strain rate dependence)
M
Fracture strength parameter (Pressure exponent)
N
Intact strength parameter (Pressure exponent)
EPSI
Reference Strain Rate
T
Maximum Tensile Strength
SFMAX
Maximum normalized Fractured Strength
HEL
Hugoniot elastic limit
PHEL
Pressure component at the at Hugoniot elastic limit
BETA
Fraction of elastic energy loss converted to hydrostatic energy
Di
Parameters for plastic strain to fracture
K1, K2
First and Second pressure coefficients
178 Materials
Field
Comments
K3
Elastic Constant (Note that K1 is the bulk modulus)
FS
Failure Criteria 0: Fails if strain exceeds FS
See Also: • LS-DYNA Keyword User’s Manual MAT_JOHNSON_HOLMQUIST_CONCRETE This material model is used for concrete under high strain rates, large strains and high pressure.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
G
Shear Modulus
A
Normalized Cohesive Strength
B
Normalized Pressure Hardening
C
Strain rate coefficient
N
Pressure Hardening Exponent
Materials 179 Materials
Field
Comments
FC
Quasi-static uniaxial compressive strength
T
Maximum Tensile hydrostatic pressure
EPSO
Reference Strain Rate
EFMIN
Plastic strain before fracture
SFMAX
Maximum Fractured Strength
PC
Crushing Pressure
UC
Crushing Volumetric Strain
PL
Locking Pressure
UL
Locking Volumetric Strain
D1, D2
Damage Constants
K1, K2, K3
Pressure Constants
FS
Failure Type
See Also: • LS-DYNA Keyword User’s Manual MAT_FINITE_ELASTIC_STRAIN_PLASTICITY An elasto-plastic material model with arbitrary stress-strain curve and arbitrary strain rate dependency. This material model uses a finite strain formulation allowing large elastic strains before yielding.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
180 Materials
Field
Comments
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
FAIL
Failure Flag 0: Plastic strain to failure. When plastic strain reaches this value, the element is deleted from calculation.
TDEL
Minimum time step size for automatic element deletion
C, P
Strain Rate Parameters
LCSS
Load Curve Id for effective Stress vs. effective plastic Strain
LCSR
Load Curve Id defining Strain Rate Effect on Yield Stress
See Also: • LS-DYNA Keyword User’s Manual MAT_LAYERED_LINEAR_PLASTICITY Defines a layered elastoplastic material with an arbitrary stress-strain curve and arbitrary strain rate dependency.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
Materials 181 Materials
Field
Comments
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
FAIL
Failure Flag 0: Plastic strain to failure. When plastic strain reaches this value, the element is deleted from calculation.
TDEL
Minimum time step size for automatic element deletion
C, P
Strain Rate Parameters
LCSS
Load Curve Id for effective Stress vs. effective plastic Strain
LCSR
Load Curve Id defining Strain Rate Effect on Yield Stress
See Also: • LS-DYNA Keyword User’s Manual MAT_UNIFIED_CREEP Defines properties of a material for elastic creep behavior.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
182 Materials
Field
Comments
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
A
Stress Coefficient
N
Stress Exponent
M
Time Exponent
See Also: • LS-DYNA Keyword User’s Manual MAT_COMPOSITE_LAYUP Defines the elastic response of composite layups that have an arbitrary number of layers through the shell thickness.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus, a Direction
Materials 183 Materials
Field
Comments
EB
Young’s Modulus, b Direction
EC
Young’s Modulus, c Direction
PRBA, PRCA, PRCB
Poisson’s Ratio in the ba, ca and cb directions
GAB, GBC, GCA
Shear Moduli in the ab, bc and ca directions
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
XP, YP, ZP
Coordinates of point p for AOPT=1 and 4
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3 and 4
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
184 Materials
MAT_COMPOSITE_MATRIX Defines the properties of materials used for the elastic response of composites where pre-integration is used to compute the extensional, bending, and coupling stiffness coefficients (available only for Belytschko-Tsay resultant shell formulation).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Cij
Coefficient of Stiffness Matrix
Materials 185 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
XP, YP, ZP
Coordinates of point p for AOPT=1 and 4
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3 and 4
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
186 Materials
MAT_COMPOSITE_DIRECT Defines properties for a material used for the elastic response of composites where pre-integration is used to compute the extensional, bending, and coupling stiffness coefficients (available only for BelytschkoTsay resultant shell formulation).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Cij
Coefficient of Stiffness Matrix
See Also: • LS-DYNA Keyword User’s Manual
Materials 187 Materials
MAT_GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM Defines the properties of a very general spring and damper. The beam is based on MAT_SPRING_GENERAL_NONLINEAR option. This model includes additional unloading options.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
KT
Translational stiffness for unloading option 2.0
KR
Rotational Stiffness for unloading option 2.0
UNLDOPT
Unloading Option
OFFSET
Offset Factor (between 0 and 1)
188 Materials
Field
Comments
DAMPF
Damping factor for stability
LCIDTR, LCIDTS, LCIDTT
Load Curve Id defining Translational Force resultant along r, s, t axes respectively vs. Translational Displacement.
LCIDRR, LCIDRS, LCIDRT
Load Curve Id defining Rotational Moment about r, s, t axes vs. Rotational Displacement.
LCIDTUR, LCIDTUS, LCIDTUT
Load Curve Id defining Translational Force resultant along r, s, t axes vs. Translational Displacement during unloading
LCIDRUR, LCIDRUS, LCIDRUT
Load Curve Id defining Rotational Moment about r, s, t axes vs. Rotational Displacement during unloading.
LCIDTDR, LCIDTDS, LCIDTDT
Load Curve Id defining Translational Damping Force along r, s, t axes vs. relative Translational Velocity.
LCIDRDR, LCIDRDS, LCIDRDT
Load Curve Id defining Rotational Damping Moment about r, s, t axes vs. relative Rotational Velocity.
LCIDTER, LCIDTES, LCIDTET
Load Curve Id defining Translational Damping Force scale factor vs. relative Displacement along r, s, t axes
LCIDRER, LCIDRES, LCIDRER
Load Curve Id defining Rotational Damping Moment scale factor vs. relative Displacement along r, s, t axes
UTFAILR, UTFAILS, UTFAILT
Translational Displacement along r, s, t at failure in Tension
WTFAILR, WTFAILS, WTFAILT
Rotational Displacement about r, s, t at failure in Tension
UCFAILR, UCFAILS, UCFAILT
Translational Displacement along r, s, t at failure in Compression
WCFAILR, WCFAILS, WCFAILT
Rotational Displacement about r, s, t at failure in Compression
IUR, IUS< IUT
Initial Translational Displacement along r, s, t directions
IWR, IWS, IWT
Initial Rotational Displacement about r, s, t axes
See Also: • LS-DYNA Keyword User’s Manual
Materials 189 Materials
MAT_GURSON Defines the material properties for the Gurson dilational plastic material model (available only for shell elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
N
Exponent in power law
Q1, Q2
Parameters
FC
Critical void volume fraction
F0
Initial void volume fraction
EN
Mean nucleation strain
SN
Standard deviation SN of the normal distribution of εN
FN
Void Volume Fraction of nucleating particles
ETAN
Hardening Modulus
190 Materials
Field ATYP
Comments Hardening Type 1: Power Law 2: Linear 3: 8 points curve
FF0
Failure void volume fraction
Li
Element Length Value
FFi
Corresponding failure void volume fraction
LCSS
Load Curve id defining effective Stress vs. effective plastic Strain
LCLF
Load Curve Id defining Failure Void Volume Fraction vs. Element Length
NUMINT
No of through thickness integration points which must fail before element is deleted
LCF0
Lod curve Id defining initial void volume fraction f0 vs. element length.
LCFC
Lod curve Id defining initial void volume fraction fN vs. element length.
LCFN
Lod curve Id defining initial void volume fraction f0 vs. element length.
VGTYP
Type of void growth behavior: .EQ. 0: void growth in tension, and void contraction in compression, but never below f0 (default). .EQ. 1: void growth in tension only. .EQ. 2: void growth in tension, and void contraction in compression, even below f0.
See Also: • LS-DYNA Keyword User’s Manual
Materials 191 Materials
MAT_GURSON_RCDC Defines the material properties for the Gurson model with Wilkins Rc-Dc (for shell elements only).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
N
Exponent in power law
Q1, Q2
Parameters
FC
Critical void volume fraction
F0
Initial void volume fraction
EN
Mean nucleation strain
SN
Standard deviation SN of the normal distribution of εN
FN
Void Volume Fraction of nucleating particles
192 Materials
Field
Comments
ETAN
Hardening Modulus
ATYP
Hardening Type 1: Power Law 2: Linear 3: 8 points curve
FF0
Failure void volume fraction
Li
Element Length Value
FFi
Corresponding failure void volume fraction
LCSS
Load Curve id defining effective Stress vs. effective plastic Strain
LCLF
Load Curve Id defining Failure Void Volume Fraction vs. Element Length
NUMINT
No of through thickness integration points which must fail before element is deleted
ALPHA
Parameter α for Rc-Dc Model
BETA
Parameter β for Rc-Dc Model
GAMMA
Parameter γ for Rc-Dc Model
D0
Parameter D0 for Rc-Dc Model
B
Parameter b for Rc-Dc Model
LAMBDA
Parameter λ for Rc-Dc Model
DS
Parameter ds for Rc-Dc Model
L
Characteristic element length for Rc-Dc Material
See Also: • LS-DYNA Keyword User’s Manual
Materials 193 Materials
MAT_GENERAL_NONLINEAR_1DOF_DISCRETE_BEAM Defines the material properties for a very general spring and damper. The beam is based on MAT_SPRING_GENERAL_NONLINEAR option and is a one dimensional version of 6DOF_DESCRETE_BEAM. This model includes additional unloading options.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Translational stiffness for unloading option 2
UNLDOPT
Unloading option
OFFSET
Offset to determine permanent set upon unloading if the UNLDOPT equals to 3.
DAMPF
Damping factor for stability
LCIDT
Load Curve Id defining Translational Force along the axis vs. relative Translational Displacement.
LCIDTU
Load Curve Id defining Translational Force along the axis vs. relative Translational Displacement, during unloading
LCIDTD
Load Curve Id defining Translational Damping Force along the local axis vs. relative Translational Velocity.
LCIDTE
Load Curve Id defining Translational Damping Force scale factor along the local axis vs. relative Displacement.
UTFAIL
Translational displacement at failure in tension
194 Materials
Field
Comments
UCFAIL
Translational displacement at failure in compression
IU
Initial translational displacement along the axis
See Also: • LS-DYNA Keyword User’s Manual MAT_HILL_3R Defines the properties for the Hill’s planar anisotropic material model with 3 R values.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
Materials 195 Materials
Field HR
Comments Hardening Rule 1: Linear 2: Exponential 3: Load Curve
P1, P2
Material Parameters
R00, R45, R90
Lankford parameters
LCID
Load Curve Id for the hardening rule
Epsilon_0
ε0 for determining initial yield stress for exponential hardening
SPI
Parameter to redefine ε0
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
blank1, blank2, blank3
Blank Fields
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT=3
See Also: • LS-DYNA Keyword User’s Manual
196 Materials
MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY Defines an elasto-plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency (available only for shell elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
FAIL
Failure flag
TDEL
Minimum time step size for automatic element deletion
C, P
Strain Rate Parameters
LCSS
Load Curve Id defining effective Stress vs. effective plastic Strain
LCSR
Load Curve Id defining Strain Rate scaling effect on Yield Stress
VP
Formulation for Rate Effects
EPSTHIN
Thinning Plastic Strain at Failure
EPSMAJ
Major Plastic Strain at Failure
NUMINT
No. of through thickness integration points that must fail before element is deleted
See Also: • LS-DYNA Keyword User’s Manual
Materials 197 Materials
MAT_PLASTICITY_COMPRESSION_TENSION Defines an isotropic elastic-plastic material allowing different yield stress versus plastic strain curves in compression and tension.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
C, P
Strain Rate Parameters
FAIL
Failure Flag
TDEL
Minimum time step size for automatic element deletion
LCIDC
Load Curve Id defining Yield Stress vs. effective Plastic Strain in compression
LCIDT
Load Curve Id defining Yield Stress vs. effective Plastic Strain in tension
198 Materials
Field
Comments
LCSRC
Optional load curve Id defining strain rate scaling effect on yield stress when the material is in compression
LCSRT
Optional load curve Id defining strain rate scaling effect on yield stress when the material is in tension
SRFLAG
Formulation for rate effects: .EQ. 0: Total strain rate ; .EQ. 1: Deviatoric strain rate
LCFAIL
Load curve Id defining failure strain vs. strain rate
PC
Compressive mean stress (pressure) at which the yield stress follows the Load Curve ID, LCIDC
PT
Tensile mean stress (pressure) at which the yield stress follows the Load Curve ID, LCIDT
PCUTC
Pressure cut-off in compression
PCUTT
Pressure cut-off in tension
PCUTF
Pressure cut-off flag: 0 = inactive ; 1 = active
K
(optional) bulk modulus for the viscoelastic material. If nonzero, a Kelvin type will be used.
NUM_RFS
Number of terms used for shear relaxationmodulus/shear decay constant
GI1
(optional) shear relaxation modulus for the i-th term
BETAI1
(optional) shear decay constant for the i-th term
See Also: • LS-DYNA Keyword User’s Manual
Materials 199 Materials
MAT_MODIFIED_HONEYCOMB Defines the properties for aluminum honeycomb crushable foam materials with anisotropic behavior.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
VF
Relative volume at which honeycomb is fully compacted
MU
Material viscosity coefficient
BULK
Bulk Viscosity Flag 0: Not used 1: Active and MU=0
200 Materials
Field LCA
Comments Load Curve ID, defining: >0: Stress along a- axis vs. strain along a-axis 0: Stress along b- axis vs. strain along b-axis 0: Stress along c- axis vs. strain along c-axis 0: Shear Stress vs. shear strain 0: Shear Stress-ab vs. shear strain-ab 0: Shear Stress-bc vs. shear strain-bc 0: Shear Stress-ca vs. shear strain-ca 0)
RO
Mass Density of the material
K
Bulk Modulus
G
Shear Modulus
N
Number of statistical links
Materials 203 Materials
Field
Comments
LCID
Load Curve id defining Relaxation curve for shear
TRAMP
Optional ramp time for loading
NT
Number of Prony series terms in fit
NUM_RFS
Number of viscoelastic constants
GIi
Optional i-th shear Relaxation Modulus i
BETAIi
Optional i-th shear Decay Constant
See Also: • LS-DYNA Keyword User’s Manual MAT_HEART_TISSUE Defines the material properties for heart tissue as described in the paper by Guccione, McCulloch and Waldman [1991]. This model is transversely anisotropic.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
C, B1, B2, B3
Material Coefficients
204 Materials
Field
Comments
P
Pressure in muscle tissue
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal. 4: Locally orthotropic in cylindrical coordinate system with the material axis determined by a vector v, and an originating point, P, which defines the centerline axis. This option is for solid elements only.
MACF
Material axes change flag: 1 = no change (default) ; 2 = switch material axes a and b 3 = switch material axes a and c ; 4 = switch material axes b and c
XP, YP, ZP
Coordinates of point p for AOPT=1 and 4
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3 and 4
Di
Component of Vector d, for AOPT=2
BETA
Material Angle (Degrees), for AOPT = 3
See Also: • LS-DYNA Keyword User’s Manual
Materials 205 Materials
MAT_LUNG_TISSUE Defines the material properties for a hyperelastic material model for heart tissue combined optionally with linear viscoelasticity.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Bulk Modulus
C, DELTA, ALPHA, BETA, C1, C2
Material Coefficients
LCID
Relaxation curve for shear
TRAMP
Optional ramp time for loading
NT
Number of Prony series terms in fit
NUM_RFS
Number of viscoelastic constants
GIi
Optional i-th shear Relaxation Modulus
BETAIi
Optional i-th shear Decay Constant
See Also: • LS-DYNA Keyword User’s Manual
206 Materials
MAT_SPECIAL_ORTHOTROPIC This material model defines the properties for a material model developed for the Belytschko-Tsay and the C0 triangle shell elements. It is based on a resultant stress formulation. In plane behavior is treated separately from bending in order to model perforated materials such as television shadow masks.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
YS
Yield Stress
EP
Plastic Hardening Modulus
EiiP
Young’s Modulus (in-plane) in i- direction
NUijP
Poisson’s Ratio in plane ij
GijP
Shear Modulus in Plane ij
EiiB
Young’s Modulus (Bending) in i-direction
NUijB
Poisson’s Ratio (Bending) in ij plane
G12B
Shear Modulus (Bending) in 12 plane
Materials 207 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below. 3: Locally orthotropic with material axis determined by rotating the material axes about the element normal by an angle, BETA, from a line in the plane of the element defined by the cross product of the vector v with the element normal.
blank i
Blank Field
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Material angle (degrees), for AOPT = 3
See Also: • LS-DYNA Keyword User’s Manual
208 Materials
MAT_MODIFIED_FORCE_LIMITED This material model is an extension of MAT_FORCE_LIMITED (MAT_029). In addition to plastic hinge and collapse mechanisms, yield moments may be defined as a function of axial force. The moment transmitted by the hinge is defined by a moment-plastic rotation relationship.
Materials 209 Materials
210 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
Materials 211 Materials
Field
Comments
DF
Damping Factor
AOPT
Axial load curve option 0: Force vs. Strain 1: Force vs. change in length
YTFLAG
Flag to allow beam to yield
ASOFT
Axial elastic softening factor
M1, M2, ..., M8
Applied End Moments
LC1, LC2, ..., LC8
Load Curve Ids corresponding to applied end moments
LPSi
Load Curve Id for plastic moment vs. rotation about s-axis at node i
SFSi
Scale factor, plastic moment vs. rotation about s- axis at node i
YMSi
Yield moment about s- axis at node i for interaction calculations
LPTi
Load Curve Id for plastic moment vs. rotation about t-axis at node i
SFTi
Scale factor, plastic moment vs. rotation about t- axis at node i
YMTi
Yield moment about t- axis at node i for interaction calculations
LPR
Load Curve Id for plastic torsional moment vs. rotation
SFR
Load Curve Id for Scale factor vs. rotation
YMR
Torsional Yield moment for interaction calculation
LYSi
Load Curve Id for yield moment vs. axial force along axis s at node i
SYSi
Load Curve Id for Scale factor applied to corresponding load curve LYSi
LYTi
Load Curve Id for yield moment vs. axial force along axis t at node i
SYTi
Load Curve Id for Scale factor applied to corresponding load curve LYTi
LYR
Load Curve Id for yield moment vs. axial force for the torsional axis
LYS
Load Curve Id for the Scale factor applying to LYR
HMS1_i
Hinge moments for s axis at node 1 for hinge i
LPMS1_i
Load Curve Id for plastic moment vs. plastic rotation for HMS1_i
HMS2_i
Hinge moments for s axis at node 2 for hinge i
LPMS2_i
Load Curve Id for plastic moment vs. rotation for HMS2_i
HMT1_i
Hinge moments for t axis at node 1 for hinge i
LPMT1_i
Load Curve Id for plastic moment vs. rotation for HMT1_i
HMT2_i
Hinge moments for t axis at node 2 for hinge i
LPMT2_i
Load Curve Id for plastic moment vs. rotation for HMT2_i
212 Materials
Field
Comments
HMR_i
Hinge moment for the torsional axis for hinge i
LPMR_i
Load Curve Id for plastic moment vs. plastic rotation for HMR_i
See Also: • LS-DYNA Keyword User’s Manual MAT_VACUUM Defines the properties for a dummy material representing a vacuum in a multi-material Euler/ALE model.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
KW_OPTION
Title optional keywords
See Also: • LS-DYNA Keyword User’s Manual
Materials 213 Materials
MAT_RATE_SENSITIVE_POLYMER Defines the properties for simulating an isotropic ductile polymer with strain rate effects. It uses uniaxial test data.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
D0
Reference Strain Rate (D0)
N
Exponent for inelastic strain rate
Z0
Initial hardness of material (Z0)
q
Parameter used in the constitutive equation
Omega
Maximum internal stress
See Also: • LS-DYNA Keyword User’s Manual
214 Materials
MAT_TRANSVERSELY_ANISOTROPIC_CRUSHABLE_FOAM Defines the properties for extruded foam material that is transversely anisotropic, crushable, and of low density with no significant Poisson effect.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E11, E22
Elastic Moduli in the 1(axial) and 2 (transverse) direction
E12
Elastic shear Modulus in the axial-transverse plane (E12 = E13)
G
Shear Modulus
K
Bulk Modulus for Contact Stiffness
I11
Load Curve Id for Nominal Axial Stress vs. Volumetric Strain
I22
Load Curve Id for Nominal Transverse Stress vs. Volumetric Strain (I22= I33)
I12
Load Curve Id for Shear Stress components 12 and 31 vs. Volumetric Strain (I22= I31)
I23
Load Curve Id for Shear Stress components 23 vs. Volumetric Strain
Materials 215 Materials
Field
Comments
IAA
Load Curve Id for Nominal stress vs. Volumetric strain at angle, ANG, relative to the material axis
NY
Flag for symmetric yield surface
ANG
Angle corresponding to Load Curve Id, IAA
MU
Damping factor
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
ISCL
Load Curve Id for the strain rate scale factor vs. volumetric strain rate. The yield rate is scaled by the value specified by the load curve.
MSCF
Material axes change flag: 1 = no change (default) ; 2 = switch material axes a and b 3 = switch material axes a and c ; 4 = switch material axes b and c
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Components of vector v (for AOPT = 3 or 4)
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual
216 Materials
MAT_WOOD Defines the material properties for a transversely isotropic material (available only for solid elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Materials 217 Materials
Field NPLOT
Comments Plotting Option 1: Parallel damage 2: Perpendicular damage
ITER
Number of plasticity algorithm iterations
IRATE
Rate effects option 0: Turn off 1: Turn on
HARD
Perfect plasticity override
IFAIL
Erosion perpendicular to the ground 0: No 1: Yes
IVOL
Erode on negative volume or strain increments greater than 0.01 =0 No (default) ; =1 Yes
EL
Parallel Normal Modulus
ET
Perpendicular Normal Modulus
GLT
Parallel Shear Modulus (GLT=GLR)
GTR
Perpendicular Shear Modulus
PR
Poisson’s Ratio
XT
Parallel Tensile Strength
XC
Parallel Compressive Strength
YT
Perpendicular Tensile Strength
YC
Perpendicular Compressive Strength
SXY
Parallel Shear Strength
SYZ
Perpendicular Shear Strength
GF1_I
Parallel Fracture Energy in Tension
GF2_I
Parallel Fracture Energy in Shear
BFIT
Parallel softening Parameter
DMAX_I
Parallel Maximum Damage
GF1_r
Perpendicular Fracture Energy in Tension
GF2_r
Perpendicular Fracture Energy in Shear
218 Materials
Field
Comments
DFIT
Perpendicular Softening Parameter
DMAX_r
Perpendicular Maximum Damage
FLPAR
Parallel Fluidity Parameter for Tension and Shear
FLPARC
Parallel Fluidity Parameter for Compression
POWPAR
Parallel Power
FLPER
Perpendicular Fluidity Parameter for Tension and Shear
FLPERC
Perpendicular Fluidity Parameter for Compression
POWPER
Perpendicular Power
NPAR
Parallel Hardening initiation
CPAR
Parallel Hardening Rate
NPER
Perpendicular Hardening initiation
CPER
Perpendicular Hardening Rate
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
MACF
Material axes change flag: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
BETA
Material angle in degrees (for AOP = 3)
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Di
Component of Vector d, for AOPT=2
Vi
Components of vector v( for AOP = 3 and 4)
Materials 219 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_WOOD_PINE Defines the material properties for a transversely isotropic material (available only for solid elements). This model has default material properties for yellow pine.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
NPLOT
Plotting Option 1: Parallel damage 2: Perpendicular damage
ITER
Number of plasticity algorithm iterations
220 Materials
Field IRATE
Comments Rate effects option 0: Turn off 1: Turn on
HARD
Perfect plasticity override
IFAIL
Erosion perpendicular to the ground 0: No 1: Yes
IVOL
Erode on negative volume or strain increments greater than 0.01 =0 No (default) ; =1 Yes
MOIS
Percentage moisture content
TEMP
Temperature
QUAL_T
Quality Factor Option in Tension
QUAL_C
Quality Factor Option in Compression
UNITS
Units Option 0: GPa, mm, msec, Kg/mm3, KN 1: MPa, mm, msec, g/mm3, N 2: MPa, mm, sec, Mg/mm3, N 3:Psi, inch, sec, lb-sec2/inch4, lb.
IQUAL
Apply quality factors perpendicular to grain 0: Yes 1: No
Materials 221 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
MACF
Material axes change flag: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
BETA
Material angle in degrees (for AOP = 3)
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Di
Component of Vector d, for AOPT=2
Vi
Components of vector v( for AOP = 3 and 4)
See Also: • LS-DYNA Keyword User’s Manual
222 Materials
MAT_WOOD_FIR Defines the material properties for a transversely isotropic material (available only for solid elements). This model has default material properties for Douglas Fir.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
NPLOT
Plotting Option 1: Parallel damage 2: Perpendicular damage
ITER
Number of plasticity algorithm iterations
IRATE
Rate effects option 0: Turn off 1: Turn on
HARD
Perfect plasticity override
Materials 223 Materials
Field IFAIL
Comments Erosion perpendicular to the ground 0: No 1: Yes
IVOL
Erode on negative volume or strain increments greater than 0.01 =0 No (default) ; =1 Yes
MOIS
Percentage moisture content
TEMP
Temperature
QUAL_T
Quality Factor Option in Tension
QUAL_C
Quality Factor Option in Compression
UNITS
Units Option 0: GPa, mm, msec, Kg/mm3, KN 1: MPa, mm, msec, g/mm3, N 2: MPa, mm, sec, Mg/mm3, N 3:Psi, inch, sec, lb-sec2/inch4, lb.
IQUAL
Apply quality factors perpendicular to grain 0: Yes 1: No
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
MACF
Material axes change flag: =1 No Change; = 2 switch mateial axes a and b =3 switch material axes a and c ; =4 switch material axes b and c
224 Materials
Field
Comments
BETA
Material angle in degrees (for AOP = 3)
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Components of vector v( for AOP = 3 and 4)
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual MAT_PITZER_CRUSHABLE_FOAM Defines the properties for a material model that simulates isotropic crushable foams with strain rate effects. It uses uniaxial and triaxial data.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Bulk Modulus
G
Shear Modulus
PR
Poisson’s Ratio
TY
Tension Yield
SRTV
Young’s Modulus
LCPY
Load Curve Id defining pressure vs. volumetric strain
Materials 225 Materials
Field
Comments
LCUYS
Load Curve Id defining uniaxial stress vs. volumetric strain
LCRS
Load Curve Id defining Strain rate Scale Factor vs. Volumetric Strain rate
VC
Viscous Damping Coefficient
DFLG
Density Flag 0:Use Initial Density value 1: Use Current Density value
See Also: • LS-DYNA Keyword User’s Manual
226 Materials
MAT_SCHWER_MURRAY_CAP_MODEL Defines the material properties for a three invariant extension of MAT_GEOLOGIC_CAP_MODEL (MAT_025) that also includes viscoplasticity for rate effects and damage mechanics to model strain softening.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
SHEAR
Shear Modulus
BULK
Bulk Modulus
GRUN
Gruneisen Ratio
SHOCK
Shock Velocity Parameter
PORE
Flag for Pore Collapse 0: Yes 1: Constant Bulk Modulus
Materials 227 Materials
Field
Comments
ALPHA, THETA, GAMMA, BETA
Shear Failure Parameters
EFIT, FFIT
Dilitation damage mechanics parameters
ALPHAN, CALPHA
Kinematic strain hardening parameters
R0
Initial Gap Surface ellipticity, R
X0
Initial Gap Surface J1 (mean stress) axis intercept
IROCK
Material Flag 0: Soils (cap can contact) 1: Rock/Concrete
SECP
Shear Enhanced Compaction
AFIT, BFIT, RDAM0
Ductile damage mechanics parameters
W, D1, D2
Plastic volume strain parameters
NPLOT
History variable post-processed as effective plastic strain
EPSMAX
Maximum permitted strain increment
CFIT, DFIT
Brittle damage parameters
TFAIL
Tensile Failure Stress
FAILFL
Failure Flag (failed element)
DBETA, DDELTA
Rounded Vertices Parameters
VPTAU
Viscoplastic Relaxation time Parameter
ALPHA1 THETA1, GAMMA1, BETA1
Torsional scaling parameters
ALPHA2 THETA2, GAMMA2, BETA2
Triaxial extension scaling parameters
See Also: • LS-DYNA Keyword User’s Manual
228 Materials
MAT_1DOF_GENERALIZED_SPRING Defines the properties for a linear spring or damper that allows different degrees-of-freedom at two nodes to be coupled with linear spring and/or damper.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Spring Stiffness
C
Damping Constant
SCLNi
Scale Factor on force at node i
DOFNi
Active dof at node i
CIDi
Local coordinate system Id at node 1 and node 2 respectively
See Also: • LS-DYNA Keyword User’s Manual
Materials 229 Materials
MAT_FHWA_SOIL Defines the material properties for an isotropic material with damage for solid elements. The model has a modified Mohr-Coulomb surface for determining pressure dependent peak shear strength.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
NPLOT
Plotting option
SPGRAV
Specific gravity of soil
RHOWAT
Density of water
VN, GAMMAR
Viscoplastic parameters
ITERMAX
Maximum number of plastic iterations
K
Bulk Modulus
G
Shear Modulus
PHIMAX
Peak Shear strength (friction) angle (degrees)
AHYP
Coefficient A for modified Drucker-Prager surface
COH
Cohesion shear strength at zero confinement (overburden)
ECCEN
Eccentricity parameter
AN
Strain hardening percent of PHIMAX where nonlinear effects start
ET
Strain hardening amount of nonlinear effects
230 Materials
Field
Comments
MCONT
Moisture content in soil
PWD1
Parameter for pore water effects on Bulk Modulus
PWSK
Skeleton Bulk Modulus
PWD2
Parameter for pore water effects on the effective pressure
PHIRES
Minimum internal frictional angle (radians)
DINT
Volumetric strain at initial threshold damage
VDFM
Void formation energy
DAMLEV
Level of damage that will cause element deletion
EPSMAX
Maximum principal failure strain
See Also: • LS-DYNA Keyword User’s Manual MAT_FHWA_SOIL_NEBRASKA Defines the material properties for a soil model with default property values for soils used at the University of Nebraska. Default units are in millimeter, milliseconds and kilograms.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
FCTIM
Factor to multiply milliseconds by to get desired time unit
FCTMAS
Factor to multiply Kg by to get desired mass unit
FCTLEN
Factor to multiply mm by to get desired length unit
See Also: • LS-DYNA Keyword User’s Manual
Materials 231 Materials
MAT_GAS_MIXTURE Defines the material properties for a material model that simulates gas mixture and works in conjunction with the multi-material ALE formulation.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
IADIAB
Flag for turning adiabatic compression logic ON/OFF 0 = ON ; 1 = OFF
RUNIV
Universal gas constant in per-mole unit
CVi
Heat Capacity at constant volume for upto eight different gases in per-mass unit gas (If RUNIV = 0 or blank)
MOLi
Molecular weight of each ideal gas in the mixture (mass-unit/molde) (if RUNIV is nonzero)
CPi
Heat Capacity at constant pressure for upto eight different gases in permass unit gas (If RUNIV = 0 or blank)
232 Materials
Field
Comments
Bi
First order coefficient for a temperature dependent heat capacity at constant pressure for up to eight different gases (If RUNIV = 0 or blank)
Ci
Second order coefficient for a temperature dependent heat capacity at constant pressure for up to eight different gases (If RUNIV = 0 or blank)
See Also: • LS-DYNA Keyword User’s Manual MAT_CFD Defines the material properties for a material model that allows constant, isotropic fluid properties to be defined for the incompressible/low-Mach CFD solver.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RHO
Fluid Density
MU
Fluid Viscosity
K
Thermal Conductivity
CP
Heat Capacity
BETA
Coefficient of expansion
TREF
Reference Temperature
Materials 233 Materials
Field
Comments
GX, GY, GZ
Gravitational acceleration in the X, Y, Z direction
DIFFi
Diffusivity for Species i
See Also: • LS-DYNA Keyword User’s Manual MAT_CFD_CONSTANT Defines the material properties for a material model that allows constant, isotropic fluid properties to be defined for the incompressible/low-Mach CFD solver.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RHO
Fluid Density
MU
Fluid Viscosity
K
Thermal Conductivity
CP
Heat Capacity
BETA
Coefficient of expansion
TREF
Reference Temperature
GX, GY, GZ
Gravitational acceleration in the X, Y, Z direction
DIFFi
Diffusivity for Species i
234 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_DESHPANDE_FLECK_FOAM Defines the material properties for aluminum foam, used as a filler material in aluminum extrusions to enhance the energy absorbing capability of the extrusion.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
ALPHA
Parameter to Control Shape of yield surface
GAMMA, ALPHA2, BETA, SIGP
Equation parameters
EPSD
Densification strain
DERFI
Type of derivation in Material subroutine 0: Numerical 1: Analytical
CFAIL
Failure Strain
See Also: • LS-DYNA Keyword User’s Manual
Materials 235 Materials
MAT_COMPOSITE_MSC Defines the material properties for a material model to simulate the progressive failure analysis for composite materials consisting of unidirectional and woven fabric layers.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus - longitudinal direction
EB
Young’s Modulus - transverse direction
EC
Young’s Modulus - through thickness direction
PRBA, PRCA, PRCB
Poisson’s Ratio in ba, ca, and cb directions
GAB, GBC, GCA
Shear Stress in ab bc, and ca directions
236 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
MACF
Material Axes change flag: = 1 no change (default) = 2, switch material axes a and b = 3, switch material axes a and c = 4, switch material axes b and c
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Layer in-plane rotational Angle (degrees)
SAT
Longitudinal Tensile Strength
SAC
Longitudinal Compressive Strength
SBT
Transverse Tensile Strength
SBC
Transverse Compressive Strength
SCT
Through thickness Tensile Strength
SFC
Crush Strength
SFS
Fiber mode shear strength
SAB, SBC, SCA
Matrix mode Shear Strength in ab bc, and ca planes
SFFC
Scale factor for residual compressive strength
Materials 237 Materials
Field AMODEL
Comments Material Model 1: Unidirectional layer model 2: Fabric layer model
PHIC
Coulomb friction angle
E_LIMT
Element eroding axial strain
S_DELM
Scale factor for delamination criteria
OMGMX
Limit damage parameter for elastic modulus
ECRSH
Limit compressive volume strain for element eroding
EEXPN
Limit tensile volume strain for element eroding
CERATE1
Coefficient for strain rate dependent strength properties
AM1
Coefficient for strain rate softening property for fiber in a direction
See Also: • LS-DYNA Keyword User’s Manual
238 Materials
MAT_COMPOSITE_MSC_DMG Defines the material properties for a material model to simulate the progressive failure analysis for composite materials consisting of unidirectional and woven fabric layers.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
EA
Young’s Modulus - longitudinal direction
EB
Young’s Modulus - transverse direction
EC
Young’s Modulus - through thickness direction
PRBA, PRCA, PRCB
Poisson’s Ratio in ba, ca, and cb directions
GAB, GBC, GCA
Shear Stress in ab bc, and ca directions
Materials 239 Materials
Field AOPT
Comments Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
MACF
Material Axes change flag: = 1 no change (default) = 2, switch material axes a and b = 3, switch material axes a and c = 4, switch material axes b and c
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Layer in-plane rotational Angle (degrees)
SAT
Longitudinal Tensile Strength
SAC
Longitudinal Compressive Strength
SBT
Transverse Tensile Strength
SBC
Transverse Compressive Strength
SCT
Through thickness Tessile Strength
SFC
Crush Strength
SFS
Fiber mode shear strength
Sij
Transverse Shear Strength ij
SFFC
Scale factor for residual compressive strength
240 Materials
Field AMODEL
Comments Material Model 1: Unidirectional 2: Fabric
PHIC
Coulomb friction angle
E_LIMT
Element eroding axial strain
S_DELM
Scale factor for delamination criteria
OMGMX
Limit damage parameter for elastic modulus
ECRSH
Limit compressive volume strain
EEXPN
Limit tensile volume strain
CERATEi
Coefficient for strain rate dependent strength parameter, axial moduli, shear moduli, transverse moduli
See Also: • LS-DYNA Keyword User’s Manual MAT_MODIFIED_CRUSHABLE_FOAM Defines the material properties for a material model to simulate crushable foam with optional damping, tension cutoff and strain rate effects. Unloading is fully elastic. Tension is treated as elastic-perfectlyplastic at the tension cutoff value.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
Materials 241 Materials
Field
Comments
E
Young’s Modulus
PR
Poisson’s Ratio
TID
Load Curve Id defining Yield Stress vs. Volumetric Strain
TSC
Tensile Stress Cutoff
DAMP
Rate sensitivity via damping coefficient
NCYCLE
Number of cycles to determine volumetric strain rate
SRCLMT
Strain rate change limit
See Also: • LS-DYNA Keyword User’s Manual MAT_QUASILINEAR_VISCOELASTIC Defines the properties for a material model to simulate a quasi-linear, isotropic, viscoelastic material which represents biological soft tissue such as brain, kidney, etc.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Bulk Modulus
LC1
Load Curve Id for the Relaxation function in shear
242 Materials
Field
Comments
LC2
Load Curve Id for the instantaneous Elastic response in shear
N
No. of Prony series terms in fit
GSTART
Starting value for least square fit
M
No. of terms used to determine the instantaneous elastic response
S0
Strain output option to be plotted as component 7 in LS-TAURUS 0: Maximum principal strain 1: Maximum Magnitude of principal strain 2: Maximum Effective strain
E_MIN
Minimum strain rate used to generate the load curve fron Ci
E_MAX
Maximum strain rate used to generate the load curve fron Ci
GAMA1, GAMA2
Material failure parameters
KF
Material failure parameter that controls the enclosed by the failure surface. .LE 0, ignore failure criterion. .GE. 0, use actual K value for failure criterion.
EH
Damage parameter
FORM
Formulation of Model. =0 original model by Fung which relaxes to a zero stress state as time approaches to infinity. = 1 Alternative model which relaxes to the quasistatice elastic response
C1 to C6
Coefficients of the instanteneous elastic response in compression and tension
See Also: • LS-DYNA Keyword User’s Manual
Materials 243 Materials
MAT_HILL_FOAM Defines the properties for a material model to simulate a highly compressible foam based on strain energy function, proposed by Hill. This model takes Poisson’s ratio effects into account.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Bulk Modulus
N
Material constant
MU
Damping coefficient
LCID
Load Curve Id defining Force per unit area vs. Stretch Ratio
FITTYPE
Type of fit 1: Uniaxial 2: Biaxial
LCSR
Load Curve Id defining uniaxial (or biaxial, depending on FITTYPE) Stress ratio vs. Transverse Stretch Ratio
R
Mullinus effect model r coefficient
M
Mullinus effect model m coefficient
See Also: • LS-DYNA Keyword User’s Manual
244 Materials
MAT_VISCOELASTIC_HILL_FOAM Defines the properties for a material model to simulate a highly compressible foam based on strain energy function, proposed by Hill. with extensions to include large strain viscoelasticity proposed by Feng and Hallquist [2002].
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
K
Bulk Modulus
N
Material constant
MU
Damping coefficient
LCID
Load Curve Id defining Force per unit area vs. Stretch Ratio
FITTYPE
Type of fit 1: Uniaxial 2: Biaxial
LCSR
Load Curve Id defining uniaxial (or biaxial, depending on FITTYPE) Stress ratio vs. Transverse Stretch Ratio
LCVE
Load Curve Id defining the Relaxation function in shear
NT
No. of Prony series terms in fit
GSTART
Starting value for least square fit
See Also: • LS-DYNA Keyword User’s Manual
Materials 245 Materials
MAT_LOW_DENSITY_SYNTHETIC_FOAM Defines the properties of rate independent low density foams exhibiting considerably reduced properties in the loading-unloading curve after the first loading cycle.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
LCID1
Load Curve Id defining nominal Stress vs. Strain for the first loading cycle
LCID2
Load Curve Id defining nominal Stress vs. Strain for loading cycles after the first loading cycle is completed
HU
Hysteric unloading factor between 0 and 1
BETA
Decay constant to model creep in unloading
DAMP
Viscous coefficient
SHAPE
Shape factor for unloading
FAIL
Failure option after cutoff stress 0: Tensile Stress remains at cutoff 1: Tensile Stress resets to zero
246 Materials
Field BVFLAG
Comments Bulk viscosity activation flag 0: No 1: Active
ED
Optional Young’s relaxation modulus for rate effects
BETA1
Optional decay constant
KCON
Stiffness coefficient for contact interface stiffness
REF
Use reference geometry to initialize stress tensor 0: Off 1: On
TC
Tension Cutoff Stress
RFLAG
Rate type for input: = 0, LCID1 and LCID2 should be input as functions of true strain rate = 1, LCID1 and LCID2 should be functions of engineering strain rate
DIRT
Strain rate averaging flag: = 0, use weighted running average .LE. 0, average the last eleven values .GT. 0, average over the last DIRT time units
K GAMA1, GAMA2
Material failure parameters
EH
Damage parameter
See Also: • LS-DYNA Keyword User’s Manual MAT_LOW_DENSITY_SYNTHETIC_FOAM_ORTHO Defines the properties of rate independent low density foams exhibiting considerably reduced properties in the loading-unloading curve after the first loading cycle. This material model considers any orthotropic behavior after the first loading and unloading cycle of the material in the orthogonal directions.
Materials 247 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
LCID1
Load Curve Id defining nominal Stress vs. Strain for the first loading cycle
LCID2
Load Curve Id defining nominal Stress vs. Strain for loading cycles after the first loading cycle is completed
HU
Hysteric unloading factor between 0 and 1
BETA
Decay constant to model creep in unloading
DAMP
Viscous coefficient
SHAPE
Shape factor for unloading
FAIL
Failure option after cutoff stress 0: Tensile Stress remains at cutoff 1: Tensile Stress resets to zero
248 Materials
Field BVFLAG
Comments Bulk viscosity activation flag 0: No 1: Active
ED
Optional Young’s relaxation modulus for rate effects
BETA1
Optional decay constant
KCON
Stiffness coefficient for contact interface stiffness
REF
Use reference geometry to initialize stress tensor 0: Off 1: On
TC
Tension Cutoff Stress
RFLAG
Rate type for input: = 0, LCID1 and LCID2 should be input as functions of true strain rate = 1, LCID1 and LCID2 should be functions of engineering strain rate
DIRT
Strain rate averaging flag: = 0, use weighted running average .LE. 0, average the last eleven values .GT. 0, average over the last DIRT time units
K GAMA1, GAMA2
Material failure parameters
EH
Damage parameter
See Also: • LS-DYNA Keyword User’s Manual
Materials 249 Materials
MAT_SIMPLIFIED_RUBBER/FOAM Defines the properties of a rubber amd foam model defined by a single uniaxial load curve or by a family of curves at discrete strain rates.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
KM
Linear Bulk Modulus
MU
Damping coefficient
G
Shear Modulus
SIGF
Limit stress for frequency independent, frictional, damping
REF
Use Reference Geometry (defined in *INITIAL_FOAM_REFERENCE_GEOMETRY) to initialize the stress tensor. 0 = ON ; 1 = OFF
PRTEN
Tensile Poisson’s ratio. = 0 indicates that PR/BETA will serve as Poisoon’s ratio for both tension and compression in shells. Otherwise, PR/BETA will serve as Poisoon’s ratio for compression in shells.
SGL
Specimen Gauge Length
SW
Specimen Width
ST
Specimen Thickness
250 Materials
Field
Comments
LCID
Load Curve Id defining Force vs. Actual change in gauge length
TENSION
Parameter to control rate effect -1: Rate effects are treated for loading either in tension or in compression (but not for unloading) 0: Rate effects are treated for loading compressive loading only 1:Rate effects are treated identically for tension and compressive loading only
RTYPE
Strain rate type 0: True 1: Engineering
AVGOPT
Averaging option to determine strain rate (to reduce numerical noise) 0: Simple average of twelve time steps 1: Running 12-point average
PR/BETA
If value is between 0.0 and 0.5 (exclusive), the value give here is taken as Poisson’s ratio. If value is exactly 0.0 (zero), an incompressible rubber like behavior is assumed, and a value of 0.495 is used inside the software. If zero Poisson’s ratio is desired, use a small value such as 0.001 for PR.
K
Material failure parameter that controls the enclosed by the failure surface. .LE 0, ignore failure criterion. .GE. 0, use actual K value for failure criterion.
GAMA1, GAMA2
Material failure parameters
EH
Damage parameter
See Also: • LS-DYNA Keyword User’s Manual
Materials 251 Materials
MAT_SEISMIC_BEAM Defines the properties of a material characterized by lumped plasticity to be developed at the ‘node 2’ end of Belytschko-Schwer beams. The plastic yield surface allows interaction between the two moments and the axial force.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
AOPT
Axial force option 0: Axial Load Curves are Collapse Load vs. Strain NE. 0: Axial Load Curves are Collapse Load vs. Change in Length
252 Materials
Field FTYPE
Comments Formulation type for interaction 1: Parabolic coefficients 2: Japanese Code, axial force and major axis bending
DEGRADE
Flag for degrading moment behavior 0 = behavior as in previous versions 1 = Fatigue-type moment-rotation behavior 2 = FEMA-type moment-rotation behavior
IFEMA
Flag for input of FEMA thresholds = 0 No inputs ; 1 = Input of rotation thresholds only =2 Input of rotation and axial strain thresholds
LCPMS
Load Curve Id for Plastic Moment vs. Rotation about s at node 2
SFS
Scale factor on s -moment at node 2
LCPMT
Load Curve Id for Plastic Moment vs. Rotation about t at node 2
SFT
Scale factor on t -moment at node 2
LCAT
Load Curve Id for axial tensile yield force vs. total tensile strain (or elongation, see AOPT option)
SFAT
Scale factor for axial tensile force
LCAC
Load Curve Id for axial compressive force vs. strain/elongation
SFAC
Scale factor for axial compressive force
ALPHA, BETA, Parameters to define yield surface GAMMA, DELTA, A, B FOFFS
Force offset for Yield Surface
SIGY
Yield Stress
D
Depth of section used for interaction curve
W
Width of section used for interaction curve
TF
Flange Thickness of section used for interaction curve
TW
Web Thickness of section used for interaction curve
PR1 - PR4
Plastic rotation thresholds 1 to 4
TS1 - TS4
Tensile axial strain hresholds 1 to 4
CS1 - CS4
Compressive axial strain hresholds 1 to 4
Materials 253 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_SOIL_BRICK Defines the properties of clay like soils accurately.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
RLAMDA, RKAPPA, RIOTA, RBETAi
Material coefficient
RMU
Shape factor coefficient
RNU
Poisson’s ratio
RLCID
Load Curve Id referring to a curve defining up to ten pairs of ‘string-length’ vs. G/Gmax points.up to 10 points of string-length vs. Gmax
TOL
User defined tolerance for convergence checking
PGCL
Pre consolidation ground level
SUB-INC
User defined strain increment size
BLK
Elastic bulk stiffness of the soil
GRAV
Gravitational acceleration
254 Materials
Field THEORY
Comments Version of material subroutine used 0 (default) = 1995 version (vectorized) ; 4 = 1995 version (unvectorized)
RVHNH
Anisotropy parameter
XSICRIT, ALPHA
Anisotropy parameters
RVH
Anisotropy ratio (Ev/Eh)
RNU21
Anisotropy ratio (ν2/ν1)
ANISO_4
Anisotropy parameter
See Also: • LS-DYNA Keyword User’s Manual MAT_DRUCKER_PRAGER Defines the properties of materials such as soils modeled with the modified Drucker-Prager yield surface.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
GMOD
Elastic Shear Modulus
RNU
Poisson’s ratio
RKF
Failure surface shape parameter
Materials 255 Materials
Field
Comments
PHI
Angle of friction (radians)
CVAL
Cohesive Value
PSI
Dilation angle (radians)
STR_LIM
Factor for calculating minimum shear strength of material which is calculated as STR_LIM*CVAL
GMODDP
Depth at which shear modulus is correct
PHIDP
Depth at which friction angle is correct
CVALDP
Depth at which cohesive value is correct
PSIDP
Depth at which dilation angle is correct
GMODGR
Gradient at which shear modulus increases with depth
PHIGR
Gradient at which friction angle increases with depth
CVALGR
Gradient at which cohesive value increases with depth
PSIGR
Gradient at which dilation angle increases with depth
See Also: • LS-DYNA Keyword User’s Manual
256 Materials
MAT_RC_SHEAR_WALL Defines the properties of materials to model cyclic shear loading of reinforced concrete walls (available only for shell elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
TMAX
Ultimate shear stress
Materials 257 Materials
Field
Comments
Fc
Unconfirmed compressive strength of Concrete
PREF
Percent reinforcement
FYIELD
Yield stress of reinforcement
SIG0
Overburden stress
UNCONV
Unit conversion factor, to compute ultimate tensile stress of Concrete
ALPHA
Shear span factor
FT
Cracking stress in direct tension
ERIENF
Young’s Modulus for reinforcement
A, B, C, D, E
Hysteresis constants to determine shape of the hysteresis loops
F
Strength gradient factor
Yi
Shear strain points on stress vs. strain curve
Ti
Shear stress points on stress vs. strain curve
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Vi
Component of Vector v, for AOPT=3
Di
Component of Vector d, for AOPT=2
BETA
Layer in-plane rotational Angle
See Also: • LS-DYNA Keyword User’s Manual
258 Materials
MAT_CONCRETE_BEAM Defines an elasto-plastic material with an arbitrary stress-strain curve and arbitrary strain rate dependency. Also, failure based on plastic strain or a minimum time step can be defined.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
E
Young’s Modulus
PR
Poisson’s Ratio
SIGY
Yield Stress
ETAN
Tangent Modulus
C, P
Strain Rate Parameters
FAIL
Failure Flag
TDEL
Minimum time step size for automatic element deletion
LCSS
Load Curve Id defining Effective Stress vs. Effective Plastic Strain in compression
LCSR
Load Curve Id defining Strain rate effects on Yield Stress
Materials 259 Materials
Field NOTEN
Comments No-tension flag 0: Takes tension 1: Does not take Tension 2: Takes tension upto value given by TENCUT (Tension cutoff)
TENCUT
Tension cutoff stress
SDR
Stiffness degradation factor
See Also: • LS-DYNA Keyword User’s Manual MAT_GENERAL_SPRING_DISCRETE_BEAM Defines the properties of materials with elastic and elastoplastic springs with damping to be represented by discrete beam elements using six springs, each acting along one of the six local degrees-of-freedom.
260 Materials
For elastic behavior, use a load curve of yield force or moment versus displacement or rotation. For inelastic case, use a load curve of yield force or moment versus plastic deflection or rotation.
Materials 261 Materials
262 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
DOFi
Active degree-of-freedom
TYPEi
Behavior 0: Elastic 1: Inelastic
Ki
Elastic loading/unloading stiffness
Di
Optional viscous damping coefficient
CDFi
Compressive displacement at failure
TDFi
Tensile displacement at failure
FLCIDi
Load Curve Id defining Force (or Moment) vs. Displacement for nonlinear elastic (TYPE1 = 0). For inelastic behavior, this curve defines the yield force vs. plastic deflection.
HLCIDi
Load Curve Id defining Force vs. Relative Velocity
C1_i, C2_i
Damping coefficients
DLEi
Scale factor for time unit
GLCIDi
Load Curve Id defining scale factor vs. deflection for HLCIDi
See Also: • LS-DYNA Keyword User’s Manual
Materials 263 Materials
MAT_SEISMIC_ISOLATOR Defines the properties of materials used as sliding and elastometric seismic isolation bearings. This material model uses a bi-directional coupled plasticity theory (available only for discrete beam elements).
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
A, GAMMA, BETA
Non dimensional variable
DISPY
Yield displacement
STIFFV
Vertical stiffness
ITYPE
Type 0: Sliding 1: Elastomeric
PRELOAD
Vertical preload
DAMP
Damping ratio
MXi
Moment factor at end i in local x direction
MYi
Moment factor at end i in local y direction
FMAX
Maximum dynamic friction coefficient
264 Materials
Field
Comments
DELF
Difference between maximum and Static Friction coefficient
AFRIC
Velocity multiplier in sliding friction equation
RADX
Radius for sliding in local x direction
RADY
Radius for sliding in local y direction
RADB
Radius of retaining ring
STIFFL
Stiffness for lateral contact against retaining ring
STIFFTS
Stiffness for tensile vertical response (sliding)
FORCEY
Yield force
ALPHA
Ratio of post and pre yielding stiffness
STIFFT
Stiffness for tensile vertical response (elastomeric)
DFAIL
Lateral displacement at which isolator fails
FMAXYC
Maximum dynamic friction coefficient in compression in local y-direction
FMAXXT
Maximum dynamic friction coefficient in tension in local x-direction
FMAXYT
Maximum dynamic friction coefficient in tension in local y-direction
YLOCK
Stiffness locking the local y- displacement (optional in single axis sliding)
See Also: • LS-DYNA Keyword User’s Manual
Materials 265 Materials
MAT_JOINTED_ROCK Defines the properties of jointed rocks.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
RO
Mass Density of the material
GMOD
Elastic Shear Modulus
RNU
Poisson’s ratio
RKF
Failure surface shape parameter
PHI
Angle of friction (radians)
CVAL
Cohesive Value
PSI
Dilation angle (radians)
STR_LIM
Factor for calculating minimum shear strength of material which is calculated as STR_LIM*CVAL
NPLANES
No of joint planes
266 Materials
Field ELASTIC
Comments Flag for Elastic Behavior 0: Non elastic 1: Elastic
LCCPDR
Load Curve Id for extra cohesion for parent material (dynamic relaxation)
LCCPT
Load Curve Id for extra cohesion for parent material (transient)
LCCJDR
Load Curve Id for extra cohesion for joints (dynamic relaxation)
LCCJT
Load Curve Id for extra cohesion for joint material (transient)
LCSFAC
Load Curve Id giving factor on Strength vs. Time
GMODDP
Depth at which shear modulus is correct
PHIDP
Depth at which friction angle is correct
CVALDP
Depth at which cohesive value is correct
PSIDP
Depth at which dilation angle is correct
GMODGR
Gradient at which shear modulus increases with depth
PHIGR
Gradient at which friction angle increases with depth
CVALGR
Gradient at which cohesive value increases with depth
PSIGR
Gradient at which dilation angle increases with depth
DIPi
Angle (degrees) of plane below the horizontal
STRIKEi
Plan view angle (degrees) of downhill vector drawn on the plane
CPLANEi
Cohesion for shear behavior on plane i
FRPLANEi
Friction angle for shear behavior on plane i
TPLANEi
Tensile strength across plane i
SHRMAXi
Maximum shear stress on plane i
LOCALi
DIP and STRIKE Coordinate System flag 0: with respect to Global axes 1: with respect to element local axes
See Also: • LS-DYNA Keyword User’s Manual
Materials 267 Materials
MAT_SPRING_ELASTIC Defines the properties of a translational or rotational elastic spring placed between two nodes. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
K
Elastic Stiffness (Translational or Rotational)
See Also: • LS-DYNA Keyword User’s Manual MAT_DAMPER_VISCOUS Defines the properties of translational and rotational dampers located between two nodes. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
DC
Damping Constant (Force/Displacement rate or Moment/Rotation rate)
268 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_SPRING_ELASTOPLASTIC Defines the properties of discrete springs providing an elastoplastic translational or rotational spring with isotropic hardening located between two nodes. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
K
Elastic Stiffness (Translational or Rotational)
KT
Tangent Stiffness
FY
Yield Force or Moment
See Also: • LS-DYNA Keyword User’s Manual
Materials 269 Materials
MAT_SPRING_NONLINEAR_ELASTIC Defines the properties of discrete springs providing a nonlinear elastic translational or rotational spring with arbitrary force versus displacement and moment versus rotation data. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
LCD
Load Curve Id defining Force vs. Displacement or Moment vs. Rotation
LCR
Load Curve Id defining Scale factor on Force or Moment as a function of relative velocity, or rotational velocity respectively
See Also: • LS-DYNA Keyword User’s Manual
270 Materials
MAT_DAMPER_NONLINEAR_VISCOUS Defines the properties of discrete dampers providing a viscous translational or rotational damper with arbitrary force versus velocity or a moment versus rotational velocity data. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
LCDR
Load Curve Id defining the Force vs. rate of Displacement or Moment vs. rate of Rotation relationship
See Also: • LS-DYNA Keyword User’s Manual MAT_SPRING_GENERAL_NONLINEAR Defines the properties of discrete springs providing a general nonlinear translational or rotational spring with arbitrary loading and unloading data. It also considers hardening or softening. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
Materials 271 Materials
Field
Comments
MID
Material identification number (Integer > 0)
LCDL
Loading Curve Id for Force vs. Displacement or Moment vs. Rotation
LCDU
Unloading Load Curve Id for Force vs. Displacement or Moment vs. Rotation
BETA
Hardening parameter
TYI
Initial Yield force in tension
CYI
Initial Yield force in compression
See Also: • LS-DYNA Keyword User’s Manual MAT_SPRING_MAXWELL Defines the properties of discrete springs providing a three Parameter Maxwell Viscoelastic translational or rotational spring. Only one degree of freedom is connected.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
K0
Short term stiffness
KI
Long term stiffness
BETA
Decay constant
TC
Cutoff time. After this time a constant force/moment transmitted
272 Materials
Field
Comments
FC
Force/Moment after cutoff time
COPT
Time implementation option 0: Incremental time change 1: Continuous time change
See Also: • LS-DYNA Keyword User’s Manual MAT_SPRING_INELASTIC Defines the properties of discrete springs and dampers providing an inelastic tension or compression only, translational or rotational spring.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
LCFD
Load Curve Id defining the Force/Torque vs. Displacement/Twist relationship
KU
Unloading Stiffness
CTF
Flag for compression/tension -1: Tension only 1: Compression only (Default CTF value is 0, which is same as 1)
See Also: • LS-DYNA Keyword User’s Manual
Materials 273 Materials
MAT_SPRING_TRILINEAR_DEGRADING Defines the properties of concrete shear walls under seismic loading modelled as discrete elements. It represents cracking of the concrete, yield of the reinforcement, and overall failure.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
DEFL1
Deflection at point where concrete cracks
F1
Force corresponding to DEFL1
DEFL2
Deflection at reinforcement yield
F2
Force corresponding to DEFL2
DEFL3
Deflection at complete failure
F3
Force corresponding to DEFL3
FFLAG
Failure Flag
See Also: • LS-DYNA Keyword User’s Manual
274 Materials
MAT_SPRING_SQUAT_SHEARWALL Defines the properties of squat shear walls modelled as discrete elements. This material model allows concrete cracking, reinforcement yield, and ultimate strength, followed by degradation of strength, leading finally to collapse.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
A14, B14, C14, D14, E14
Material coefficient
LCID
Load Curve Id referencing the maximum strength envelope curve
FSD
Sustained strength reduction factor
See Also: • LS-DYNA Keyword User’s Manual
Materials 275 Materials
MAT_SPRING_MUSCLE Defines the properties for discrete springs and dampers. This is a Hill-type muscle model with activation.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
L0
Initial muscle length
VMAX
Maximum CE shortening velocity
SV
Scale factor for Vmax vs. Active State
A
Scale factor for Activation Level vs. Time function
FMAX
Peak isometric force
TL
Scale factor for Active tension vs. length function
TV
Scale factor for Active tension vs. velocity function
FPE
Scale factor for Force vs. length function, for parallel elastic element
LMAX
Relative length at FPE=FMAX
KSH
Constant governing the exponential rise of FPE
LCID_SV
Load Curve Id defining Vmax vs. active state
LCID_A
Load Curve Id defining Active level vs. Time function
LCID_TL
Load Curve Id defining Active tension vs. Length function
LCID_TV
Load Curve Id defining Active tension vs. velocity function
LCID_FPE
Load Curve Id defining Force vs. Length function
See Also: • LS-DYNA Keyword User’s Manual
276 Materials
MAT_THERMAL_ISOTROPIC Defines isotropic thermal properties of materials in coupled structural/thermal and thermal only analyses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
TGMULT
Thermal generation rate multiplier
TLAT
Phase chnage temperature
HLAT
Latent heat
HC
Heat capacity
TC
Thermal conductivity
See Also: • LS-DYNA Keyword User’s Manual MAT_THERMAL_ORTHOTROPIC Defines orthotropic thermal properties in coupled structural/thermal and thermal only analyses.
Materials 277 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
TGMULT
Thermal generation rate multiplier
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by3 vectors below.
TLAT
Phase chnage temperature
HLAT
Latent heat
278 Materials
Field
Comments
K1, K2, K3
Thermal conductivity in local x, y and z, respectively
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual MAT_THERMAL_ISOTROPIC_TD Defines temperature dependent isotropic thermal properties in coupled structural/thermal and thermal only analyses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
Materials 279 Materials
Field
Comments
TGMULT
Thermal generation rate multiplier
TLAT
Phase chnage temperature
HLAT
Latent heat
LC_C
Load Curve defining Heat capacity (C) Vs. Temperature
LC_K
Load Curve defining Thermal Conductivity (K) Vs. Temperature
See Also: • LS-DYNA Keyword User’s Manual MAT_ORTHOTROPIC_TD Defines temperature dependent orthotropic thermal properties in coupled structural/thermal and thermal only analyses.
280 Materials
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
TGMULT
Thermal generation rate multiplier
AOPT
Material Axes option 0: Locally orthotropic with material axes determined by element nodes 1, 2, and 4. (Node 1 is the local origin, Node 2 is along the local a- axis; Local c-axis is the cross product of local a-axis, and the vector from node 1 to node 4; Local b- axis is the cross product of loca c- and a- axes.) 1: Locally orthotropic with material axis determined by a point in space, and the global location of the element center; this is the a- direction. This option is for solid elements only. 2: Globally orthotropic with material axis determined by vectors below.
LC_C
Load Curve defining Heat capacity Vs. Time
LC_KX
Load Curve defining Thermal conductivity in local X Vs. Time
LC_KY
Load Curve defining Thermal conductivity in local Y Vs. Time
LC_KZ
Load Curve defining Thermal conductivity in local Z Vs. Time
XP
X-coordinate of point p for AOPT=1
YP
Y-coordinate of point p for AOPT=1
ZP
Z-coordinate of point p for AOPT=1
Ai
Component of Vector a, for AOPT=2
Di
Component of Vector d, for AOPT=2
See Also: • LS-DYNA Keyword User’s Manual
Materials 281 Materials
MAT_THERMAL_ISOTROPIC_PHASE_CHANGE Defines temperature dependent isotropic properties with phase changes in coupled structural/thermal and thermal only analyses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
TGMULT
Thermal generation rate multiplier
LC_C
Load Curve defining Heat capacity Vs. Temperature
LC_K
Load Curve defining Thermal conductivity Vs. Temperature
SOLT
Solid Temperature
LIQT
Liquid Temperature
LH
Latent Heat
282 Materials
See Also: • LS-DYNA Keyword User’s Manual MAT_THERMAL_ISOTROPIC_TD_LC Defines temperature dependent isotropic thermal properties by specifying a load curve in coupled structural/thermal and thermal only analyses.
Field
Comments
Title
Unique name identifying material model
Desc
Optional description of the material model
TITLE_OPTION
If selected material title option is used
MID
Material identification number (Integer > 0)
TRO
Thermal Density
TGRLC
Thermal generation rate value
TGMULT
Thermal generation rate multiplier
HCLC
Load Curve Id specifying Heat capacity vs. Temperature
TCLC
Load Curve Id specifying Thermal conductivity vs. Temperature
TGRLCID
Load Curve Id specifying Thermal generation rate curve number
See Also: • LS-DYNA Keyword User’s Manual
Properties 273
Properties
274 Properties
Properties Overview Typical properties include cross-sectional properties of beam elements, thicknesses of plate and shell elements, element integration rules, and hourglass controls. Properties are assigned to the elements of a specified part or element type, either directly to the elements, or indirectly through the part to which the elements belong.
Element Types and Associated Properties Thin Shell Elements Two-dimensional elements, commonly referred to as plate and shell elements, are used to represent areas in your model where one of the dimensions is small in comparison to the other two. As shown Figure 1 the thickness is substantially less than dimensions a or b.
Figure 1
Typical Plate Element
ELEMENT_SHELL - General-purpose plate elements (4-noded) capable of carrying in plane force, bending forces, and transverse shear force. The triangular element is defined by repeating the third for the fourth node. This family of elements are the most commonly used shell elements in the SimXpert crash element library. These are the element types generated by the Automesher.
Properties 275 Properties
*SECTION_SHELL - The thin shell elements are commonly referred to as the plate and shell elements within SimXpert. Their properties, are defined using the *SECTION_SHELL entry. The format of the *SECTION_SHELL entry is as follows:
276 Properties
Field
Contents
SECID
Section ID, to be referred by parts
ELFORM
Element formulation options = 1: Hughes-Liu = 2: Belytscho-Tsay = 3: BCIZ triangular shell = 4: C0 triangular shell = 5: Belytscho-Tsay membrane = 6: S/R Hughes-Liu = 8: Belytscho-Leviathan shell = 9: Fully integrated Belytscho-Tsay membrane = 10: Belytscho-Wong-Chiang = 11: Plane stress (x-y plane) = 12: Fast (co-rotational) Hughes-Liu = 13: Plane strain (x-y plane) = 14: Axisymmetric solid (y-axis of symmetry) - area weighted = 15: Axisymmetric solid (y-axis of symmetry) - volume weighted = 16: Fully integrated shell element = 17: Fully integrated DKT triangular shell element = 18: Fully integrated DK quadrilateral/triangular shell element = 20: Fully integrated linear assumed strain C0 shell = 21: Fully integrated linear assumed strain (5 DOF per node) C0 shell = 22: Linear shear panel element (3 DOF per node)
SHRF
Shear correction factor (value of 5/6 is recommended for solid plate)
NIP
Number of through thickness integration points
Properties 277 Properties
Field PROPT
Contents Printout options = 0: Average resultants and fiber lengths = 1: resultants at plan points and fiber lengths = 3: Resultants, stresses at all points, fiber lengths
QR
Quadrature rule LT 0.: Absolute value is used as the Quadrature rule EQ. 0.: Gauss Rule (up to five points permitted) EQ. 1.: Trapezoidal Rule
ICOMP
Flag for orthotropic/anisotropic layered composite material model = 0: Homogeneous =1: Composite
SETYP
2D solid element type (defined for ELFORM 13, 14, and 15) = 1: Lagrangian = 2: Eulerian (single material with voids) = 3: ALE
T1
Shell thickness at node 1
T2, T3, T4
Shell thickness at nodes 2, 3, and 4 respectively
NLOC
Location of reference surface normal to s axis (Hughes-Liu elements: ELFORM = 1 or 6)
MAREA
Nonstructural mass per unit area
IDOF
Applies to shell element types 25 and 26. .EQ. 1(default): The thickness field is continuous across the element edges for metal-forming applications. .EQ. 2: The thickness field is discontinuous across the element edges. This is necessary for applications such as crashworthiness where shell intersections, sharp included angles, and non-smooth deformations exist.
EDGSET
Edge node set, required for shell type seatbelts.
AFAC
Smoothing weight factor - simple average (No smoothing if value is -1.)
BFAC
Smoothing weight factor - volume weighting
278 Properties
Field
Contents
CFAC
Smoothing weight factor - isoparametric
DFAC
Smoothing weight factor - equipotential
EFAC
Smoothing weight factor - equilibrium
START
Start time for smoothing
END
End time for smoothing
AAFAC
ALE advection factor
DX, DY
Normalized dilatation parameters of the kernel function in X and Y directions respectively
ISPLINE
Replaces choice for the EFG kernel functions definition in *CONTROL_EFG.
IDILA
Replaces choice for the normalized dilation parameter definition in *CONTROL_EFG.
IRID
Integration Rule Id (User defined)
The element coordinate systems for the shell element is shown in Figure 2. The orientation of the element coordinate system is determined by the order of the connectivity for the nodes. The element z-axis, often referred to as the positive normal, is determined using the right-hand rule. Therefore, if you change the order of the nodal connectivity, the direction of this positive normal also reverses. This rule is important to remember when applying pressure loads or viewing the untransformed element forces or stresses. Untransformed directional element stress plots may appear strange when they are displayed by the postprocessor in SimXpert because the normals of the adjacent elements may be inconsistent. Remember that components of forces, moments, and element stresses are always output in the element coordinate system.
Figure 2
Thin Shell Element Geometry and Coordinate Systems
See Also: • LS-DYNA Keyword User’s Manual
Properties 279 Properties
Thick Shell Elements If the thickness dimension of your component is small, but not too small, in comparison to the other two, dimensions, you can model it with thick shell elements.
Figure 3
Typical Plate Element
*ELEMENT_TSHELL - Eight noded thick shell element useful for modeling thick plated components. Unlike the thin shell element, *ELEMENT_SHELL which represents the plate through the middle surface, and thickness, the 8-noded thick shell element represents plate as a hexahedron, the first four nodes representing the bottom surface, and the last four nodes representing the top surface. The thick
280 Properties
shell wedge element is defined by repeating the third for the fourth node, and repeating the seventh for the eighth node .
Figure 4
Thick Shell Element Connectivity
Properties 281 Properties
SECTION_TSHELL The properties of the thick shell elements are defined using the *SECTION_TSHELL entry. The format of the *SECTION_TSHELL entry is as follows:
Field
Contents
SECID
Section ID, to be referred by parts
ELFORM
Element formulation options = 1: 1point reduced integration (Default) = 2: Selective reduced 2X2 in plane integration = 3: Assumed strain 2X2 in plane integration
SHRF
Shear correction factor (a value of 5/6 recommended for solid section plate)
NIP
Number of through thickness integration points. (If NIP = 0, the Default value of 2 is used)
PROPT
Printout options = 0: Average resultants and fiber lengths = 1: resultants at plan points and fiber lengths = 3: Resultants, stresses at all points, fiber lengths
282 Properties
Field QR
Contents Quadrature rule LT 0.: Absolute value is used as the Quadrature rule EQ. 0.: Gauss Rule (up to five points permitted) EQ. 1.: Trapezoidal Rule
ICOMP
Flag for orthotropic/anisotropic layered composite material model = 0: Homogeneous =1: Composite
IRID
Integration Rule Id (User defined)
B1
Material angle (β1) at first integration point. This angle is measured with respect to the element edge n1-n2.
The orientation of the element coordinate system is determined by the order of the connectivity for the nodes. The element z-axis (the thickness direction) often referred to as the positive normal to the face connected by nodes n1, n2, n3, and is determined using the right-hand rule (cross product of edge vectors n1-n2 and n1-n3). Therefore, if you change the order of the nodal connectivity, the direction of this positive normal also reverses. This rule is important to remember when applying pressure loads or viewing the untransformed element forces or stresses. Untransformed directional element stress plots may appear strange when they are displayed by the postprocessor in SimXpert because the normals of the adjacent elements may be inconsistent. Remember that components of forces, moments, and element stresses are always output in the element coordinate system. See Also: • LS-DYNA Keyword User’s Manual Three-Dimensional Elements Whenever you need to model a structure that does not behave as a bar or plate structure under the applied loads, you need to use one or more of the three-dimensional elements. The three-dimensional elements are commonly referred to as solid elements. Typical engineering applications of solid elements include engine blocks, brackets, and gears. The Solid Elements in the Crash Workspace Include the Following: 1. 8 noded hexahedron 2. 6 noded pentahedron (degenerated from the 8-node hexahedron, by repeating node 4 for the last four nodes (n1, n2, n3, n4, n4, n4, n4, n4, n4) 3. 4 noded tetrahedron (degenerated from the 8-node hexahedron, by repeating node 5 for the sixth node, and repeating node 7 for the eighth node (n1, n2, n3, n4, n5, n5, n6, n4, n6)
Properties 283 Properties
4. 10 noded tetrahedron
Figure 5
Solid Elements
284 Properties
SECTION_SOLID The properties of the solid elements are entered on the *SECTION_SOLID form shown below:
Field
Contents
Title
Unique name identifying the section.
SECID
Section ID, to be referred by parts
Properties 285 Properties
Field ELFORM
Contents Element formulation options = 0: 1 point co-rotational for *MAT_MODIFIED_HONEYCOMB = 1: Constant stress solid element (Default) = 2: Fully integrated S/R solid = 3: Fully integrated quadratic 8 node element with nodal rotations = 4: S/R quadratic tetrahedron with nodal rotations = 5: 1 point ALE = 6: 1 point Eulerian = 7: 1 point Eulerian ambient = 8: acoustic = 9: 1 point co-rotational for *MAT_MODIFIED_HONEYCOMB = 10: 1 point tetrahedron = 11: 1 point ALE multi-material element = 12: 1 point integration with single material and void = 13: 1 point nodal sure tetrahedron for bulk forming = 14: 8 point acoustic = 15: 2 point pentahedron element = 16: 5 point 10 noded tetrahedron = 18: 8 point enhanced strain solid element for linear statics only
AET
Ambient element type (foe ELFORM = 7, 11 or 12) = 3: pressure outflow = 4: pressure inflow (Default for ELFORM = 7)
AFAC
Smoothing weight factor - simple average (if value is -1, smoothing turned off)
BFAC
Smoothing weight factor - volume weighting
CFAC
Smoothing weight factor - isoparametric
286 Properties
Field
Contents
DFAC
Smoothing weight factor - equipotential
START
End time for smoothing
END
Start time for smoothing
AAFAC
ALE advection factor
DX, DY, DZ
Normalized dilatation parameters of the kernel function in X, Y, and Z directions respectively
ISPLINE
Replaces choice for the EFG kernel functions definition in *CONTROL_EFG.. .EQ. 0: Cubic spline function (default) .EQ. 1: Quadratic spline function .EQ. 2: Cubic spline function with cubic shape
IDILA
Replaces choice for the normalized dilation parameter definition in *CONTROL_EFG.. .EQ. 0: Maximum distance based on the background elements .EQ. 1: Maximum distance based on the sourounding nodes
IEBT
Essential boundary condition treatment: .EQ. 1: Full transformation method .EQ. -1: w/o transformation .EQ. 2: Mixed transformation method .EQ. 3: Coupled FEM/EFG method .EQ. 4: Fast transformation method .EQ. -4: w/o transformation .EQ. 5: Fluid particle method for E.O.S and *MAT_ELASTIC_FLUID materials
Properties 287 Properties
Field IDIM
Contents Domain integration method: .EQ. 1: Local boundary integration (default) .EQ. 2: Two-point gauss integration .EQ. 3: Improved gauss integration for IEBT = 4 or -4
TOLDEF
Deformation tolerance for the activation of adaptive EFG Semi-Lagrangian and Eulerian kernel. = 0.0: Lagrangian kernel > 0.0: Semi-Lagrangian Export -> Dyna Model). This will create a keyword input file which can then be used to perform the simulation with LS-DYNA on a computer where it is installed.
Manually Invoking LS-DYNA As a part of SimXpert Installation, the LS-DYNA Analysis Code solver is installed in a subdirectory under the main installation directory and can be invoked directly. Should you need to manually invoke LS-DYNA, run the executable found under the SimXpert installation directory. To invoke LS-DYNA from Linux32: /Nastran/md2009/dyna/linux32/run_dytran jid=jobid.key iam=simxcr From Linux64: /Nastran/md2009/dyna/linux64/run_dytran jid=jobid.key iam=simxcr From Windows32: /Nastran/md2009/dyna/win32/run_dytran jid=jobid.key iam=simxcr From Windows64: /Nastran/md2009/dyna/win64/run_dytran jid=jobid.key iam=simxcr where jobid.key is a LSDYNA input deck. For Linux32, the default INSTALLROOT Path for SimXpert R4 is /msc/SimXpert/R4 For Linux64, the default INSTALLROOT Path for SimXpert R4 is /msc/SimXpert_x64/R4 For Windows32/64, the default INSTALLROOT Path for SimXpert R4 is C:\MSC.Software\SimXpert\R4
322 Perform the Simulation
Example - Crushing of a Thin Square Tube 323
Example - Crushing of a Thin Square Tube
324 Crushing of a Thin Square Tube
Crushing of a Thin Square Tube Problem Description A square cross section thin tube is to be simulated for crushing by a rigid wall moving with an initial velocity toward one end of the tube, while the other end is fixed. The basic FEA model containing the nodes and the elements is imported from a Nastran input file. Complete the crush model with materials, sections, boundary conditions, loads, and analysis and output options for performing the crush simulation. Some Key Data: Cross-section of the tube:
69.954 mm X 69.954 mm
Length of the tube:
320 mm
Thickness of the tube:
1.2 mm
Weight of the rigid wall:
0.4 ton
Initial velocity of the rigid wall: 5646 mm/sec
Steps: Following are the steps to complete the crush model.
1. Launch SimXpert Select Structures as the Workspace 2. Select the Solver Card as the GUI Options Tools -> Options -> GUI Options Select Solver Card Click Apply 3. Set the Units for the model Click Units Manager Click Standard Units Select mm, t, s as the units for Length, Mass, and Time respectively Click OK Click OK
Example - Crushing of a Thin Square Tube 325 Crushing of a Thin Square Tube
4. Import the FEA mesh from a MSC.Nastran input file File -> Input -> Nastran ... Select the file, square_tube_nast.bdf Hint:
You can find the above file in the PartFiles folder under the help folder in the SimXpert installation directory. Click Open Close the (pop-up) Notepad window (nastran.err - Notepad) The imported FEA mesh represents a quarter model of the thin square tube.
Figure 1
Quarter model of a square section tube
5. Switch the workspace to crash: Set workspace to crash 6. Create the material: Materials and Properties-> MAT [1 to 20] -> [003]MAT_PLASTIC_KINEMATIC Enter steel as the Title for the material Enter value for RO: 7.85E-9
326 Crushing of a Thin Square Tube
Enter value for E: 1.994E5 Enter value for PR: 0.30 Enter value for SIGY: 3.366E2 Enter value for ETAN: 1 Enter value for BETA: 1 Click OK 7. Create properties for the shell elements: Materials and Properties-> Section -> SECTION_SHELL Select 2 for ELFORM Enter value for SHRF: 1. Enter value for NIP: 3 Note: Hit the Enter key, after typing 3 for NIP. Otherwise, the change will not be made. Enter value for T1: 1.2 Enter value for T2: 1.2 Enter value for T3: 1.2 Enter value for T4: 1.2 Click OK 8. Assign property and material to the part: Right click on the (part) PSHELL... in the Model Browser Click Properties on the pop-up window Double click on the SECID data box, and click Select Select SECTION_SHELL_1 from the Select a PSECTION form Click OK Double click on the cell below MID, and click Select Select steel from the Select a Material form Click OK Set the value for ADPOPT to 1 Click Modify Click Exit
9. Create the boundary conditions for the tube:
Example - Crushing of a Thin Square Tube 327 Crushing of a Thin Square Tube
LBCs -> LBC -> SPC -> Boundary SPC Make sure all six DOFs are checked-in (selected) Click Store Click Exit Pick all the nodes on the bottom of the tube Click Done on the Pick panel This fixes the bottom edge of the tube against all translations and rotations.
328 Crushing of a Thin Square Tube
Top edge
z-symmetry edge
x-symmetry edge
Bottom edge (fixed)
Figure 2
Boundary conditions for the tube model
Example - Crushing of a Thin Square Tube 329 Crushing of a Thin Square Tube
LBCs -> LBC -> SPC -> Boundary SPC Check in DOFX, DOFRY, DOFRZ Click Store Click Exit Pick all the nodes on the x-symmetry edge, except the node on the bottom edge. Click Done on the Pick panel This imposes the symmetric boundary condition on the x-symmetry edge. LBCs -> LBC -> SPC -> Boundary SPC Check in DOFZ, DOFRX, DOFRY Click Store Click Exit Pick all the nodes on the z-symmetry edge, except the node on the bottom edge. Click Done on the Pick panel This imposes the symmetric boundary condition on the z-symmetry edge. 10. Create a constrained node set on all the nodes on the top edge: Nodes/Elements ->Elements -> Create -> Rigid -> Constrained Node Set Set DOF to 2 Click Store Click Exit Pick all the nodes on the top edge Click Done on the Pick panel 11. Create mass elements to represent the rigid wall: Elements -> Create -> 1 Noded -> Element Mass Enter value for MASS: 0.01 Click Store Click Exit Pick all the nodes on the top edge, except two nodes where the symmetry edges meet the top edge. Click Done on the Pick panel
330 Crushing of a Thin Square Tube
Elements -> Create -> 1 Noded -> Element Mass Enter value for MASS: 0.005 Click Store Click Exit Pick the two nodes where the symmetry edges meet the top edge Click Done on the Pick panel 12. Create the initial velocity on the top nodes: LBCs -> LBC -> Nodal BC-> Initial Velocity Enter value for VY: -5646 Click on Define App Region Pick all the nodes on the top edge Click Create 13. Create an auto single surface contact: LBCs -> Contact-> Automatic -> Auto Single Surface Click OK on the Auto Single Surface form 14. Select the dyna control options: Parameters -> Control -> [A to C] -> CONTROL ADAPTIVE Enter value for ADPFREQ: 1.E-4 Enter value for ADPTOL: 5 Select value for ADPOPT: 2 Enter value for MAXLVL: 2 Enter value for ADPSIZE: 0 Click OK Control -> [N to Z] -> CONTROL TERMINATION Enter value for ENDTIME: 3.E-3 Click OK Control -> [D to H] -> CONTROL ENERGY Select value for HGEN: 2 Select value for RWEN: 2 Select value for SLNTEN: 2 Select value for RYLEN: 1
Example - Crushing of a Thin Square Tube 331 Crushing of a Thin Square Tube
Click OK Control -> [N to Z] -> CONTROL OUTPUT Select value for NPOPT: 1 Select value for NEECHO: 3 Click OK Control -> Title ->TITLE Enter value for Title: Crushing of a thin square tube Click OK 15. Select the dyna database options: Database -> OPC -> DATABASE BINARY option Enter valuEnter value for DT_D3PLOT: 1.E-4 Check in the IOPT select box, and set its value to 1 Click OK Database -> OPC -> DATABASE option Enter value for DT_GLSTAT: 2.E-5 Enter value for DT_MATSUM: 2.E-5 Click OK 16. Save the SimXpert database: File -> Save As Enter name for the file: square_tube_crush Click Save 17. Run the Simulation: Rght-click on Simulations Enter name for Fle name: square_tube_crush Click Save 18. Exit from SimXpert: File -> Exit
19. Post-process the Results in ls-prepost
332 Crushing of a Thin Square Tube
Figure 3
Von Mises Stress at Time = 0.003
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