Manual Pam Stamp
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Pam Stamp 2G...
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PAM-STAMP 2G 2012 User’s Guide
PAM-STAMP 2G 2012
USER’S GUIDE
The documents and related know-how herein provided by ESI Group subject to contractual conditions are to remain confidential. The CLIENT shall not disclose the documentation and/or related know-how in whole or in part to any third party without the prior written permission of ESI Group.
© 2012 ESI Group. All rights reserved.
October 2012 GR/PAST/12/03/00/A
PAM-STAMP 2G 2012 © 2012 ESI Group
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CONTENTS ABOUT THIS DOCUMENT
1
Attributes /Functionalities Chapters -------------------------------------------------- 1
INTRODUCTION
5
PAM-STAMP 2G Overview ------------------------------------------------------------ 5
PRODUCT START UP
15
ASCII Input ------------------------------------------------------------------------------- 15 Customization ---------------------------------------------------------------------------- 18 Files ---------------------------------------------------------------------------------------- 23 Solver Manager Configuration------------------------------------------------------- 32 Solver Manager Start ------------------------------------------------------------------ 40 Solver Manager Activity --------------------------------------------------------------- 43 Calculation Stop ------------------------------------------------------------------------- 44
FINITE ELEMENT AND NUMERICAL MODELS
45
Algorithm ---------------------------------------------------------------------------------- 45 Time Step & Increments -------------------------------------------------------------- 59 Elements ---------------------------------------------------------------------------------- 68 Material Properties --------------------------------------------------------------------- 76 HILL 48 Material Law ------------------------------------------------------------------ 80 HILL’s 90 Material Law ---------------------------------------------------------------- 84 BARLAT89 Material Law -------------------------------------------------------------- 86 BARLAT91 Material Law -------------------------------------------------------------- 87 BARLAT2000 Material Law ---------------------------------------------------------- 89 VEGTER Material Law ---------------------------------------------------------------- 92 Matfem Failure Criterion ------------------------------------------------------------ 100 SUPERPLASTIC Material Law ---------------------------------------------------- 106 Mooney-Rivlin Material Law-------------------------------------------------------- 112 Material Hardening Laws ----------------------------------------------------------- 113 Thermal Material Option ------------------------------------------------------------ 130 MetallurgIcal Material Option ------------------------------------------------------ 137 EWK Rupture Model ----------------------------------------------------------------- 148 Material File Format (.psm) -------------------------------------------------------- 155
SIMULATION CONCEPTS
175
Contact and Friction ------------------------------------------------------------------ 175 Objects & Attributes ------------------------------------------------------------------ 193 Kinematics ------------------------------------------------------------------------------ 200 Force and Pressure ------------------------------------------------------------------ 206 Fluid Cell and Aquadraw ------------------------------------------------------------ 209
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Rigid Body ------------------------------------------------------------------------------ 217 Adaptive Meshing --------------------------------------------------------------------- 223 Drawbead ------------------------------------------------------------------------------- 232 Symmetry Plane----------------------------------------------------------------------- 258 Picking ----------------------------------------------------------------------------------- 260 Distributed Memory Process (DMP) --------------------------------------------- 265 Process Setup ------------------------------------------------------------------------- 271 Offset ------------------------------------------------------------------------------------- 285 Mesh Check and Cleanup ---------------------------------------------------------- 290 Filleting ---------------------------------------------------------------------------------- 297 Substructuring ------------------------------------------------------------------------- 301 Mapping --------------------------------------------------------------------------------- 309 Mapping Files -------------------------------------------------------------------------- 317 User-Defined Attribute --------------------------------------------------------------- 332
ANALYSIS TOOLS
335
Contours--------------------------------------------------------------------------------- 335 Forming Limit Diagram (FLD)------------------------------------------------------ 349 Draw-In Tools -------------------------------------------------------------------------- 356 Blank Shifting -------------------------------------------------------------------------- 362 Solver Analysis Tools ---------------------------------------------------------------- 365 User Interface Analysis Tools ----------------------------------------------------- 371 Scripting --------------------------------------------------------------------------------- 383 Reporting -------------------------------------------------------------------------------- 390
SIMULATION METHODOLOGY FOR DESIGN AND STAMPING FEASIBILITY
397
Introduction ----------------------------------------------------------------------------- 397 Customization -------------------------------------------------------------------------- 399 Die Design (PAM-DIEMAKER) ---------------------------------------------------- 406 Part Preparation for Die Design (PAM-DIEMAKER) ------------------------ 411 Evaluation of the Tool Design (Pam-QuikStamp PLUS) ------------------- 421 Process Verification (Pam-Autostamp) ----------------------------------------- 441 Binder Generation for Die Design (PAM-DIEMAKER) ---------------------- 461 Run-Offs and Addendum Generation for Die Design (PAMDIEMAKER) --------------------------------------------------------------------------- 465 Re-Engineering the Die Face (PAM-DIEMAKER) --------------------------- 479 Process Verification: Penalty Contact (Pam-autostamp) ------------------- 484 Iteration on Design and Stamping Feasibility---------------------------------- 488
SIMULATION METHODOLOGY FOR STANDARD FORMING
497
Introduction ----------------------------------------------------------------------------- 497 Customization -------------------------------------------------------------------------- 502 Creation of the Tools ----------------------------------------------------------------- 509 Blank Meshing ------------------------------------------------------------------------- 539
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Creation of DRAWBEADS ---------------------------------------------------------- 547 Analysis Entities ----------------------------------------------------------------------- 549 Process Setup ------------------------------------------------------------------------- 550 Simulation and Postprocess ------------------------------------------------------- 564
SIMULATION METHODOLOGY FOR SPECIFIC PROCESSES
567
Tailored and Patchwork Blanks --------------------------------------------------- 567 Hot Forming ---------------------------------------------------------------------------- 582 Flanging --------------------------------------------------------------------------------- 617 Roll Hemming -------------------------------------------------------------------------- 623 Hemming -------------------------------------------------------------------------------- 663 Control Table --------------------------------------------------------------------------- 664 Die Compensation and Multi-op -------------------------------------------------- 670 Blank and Trimming Line Optimization ------------------------------------------ 697 Springback Measurement ---------------------------------------------------------- 716 Cosmetic Defects Analysis --------------------------------------------------------- 736 Press Force Analysis ---------------------------------------------------------------- 751 Volume Blank -------------------------------------------------------------------------- 758 Simulation with Ironing - T.T.S Element ---------------------------------------- 765 Gas Springs ---------------------------------------------------------------------------- 768 Drawslit or Lancing ------------------------------------------------------------------- 771 CRASHFORMING -------------------------------------------------------------------- 773 Stamping Inverse --------------------------------------------------------------------- 774
SIMULATION METHODOLOGY FOR TUBE
789
Introduction ----------------------------------------------------------------------------- 789 Customization -------------------------------------------------------------------------- 792 Tube Design Module (PAM-TUBEMAKER)------------------------------------ 799 Bending Simulation Feasibility ---------------------------------------------------- 826 Tube Bending -------------------------------------------------------------------------- 834 Tube Hydroforming ------------------------------------------------------------------- 843
DELTAMESH
855
Introduction ----------------------------------------------------------------------------- 855 CAD Model Exchange from CAD Systems to DeltaMESH ---------------- 858 Meshing Access ----------------------------------------------------------------------- 898 DeltaMESH Parameters ------------------------------------------------------------ 902 Mesh Check and Repair ------------------------------------------------------------ 919 The Remeshing Action -------------------------------------------------------------- 931 The Multipatching Action ------------------------------------------------------------ 937 Other DeltaMESH Actions ---------------------------------------------------------- 942 Configuration of Meshing Parameters ------------------------------------------- 946
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PAM-STAMP 2G 2012 © 2012 ESI Group
USER’S GUIDE (released: Oct-12)
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ABOUT THIS DOCUMENT ATTRIBUTES /FUNCTIONALITIES CHAPTERS Here is a list of the chapters on the User’s Guide describing the attributes and functionalities available in PAM-STAMP 2G. For Pam Quikstamp plus project, the user must also refer to the Evaluation of the tool design (Pam Quikstamp) chapter in the Simulation Methodology for design and stamping feasibility section. For Inverse project, the user must refer to the Stamping Inverse chapter in the Simulation concepts section and to the Tube Inverse chapter in the Simulation methodology for tube section. ATTRIBUTES: /FUNCTIONALITIES
SECTION
CHAPTER
PAGE
Analysis
Simulation methodology for Analysis entities Standard Forming
556
Aquadraw
Simulation Concepts
209
Autopositioning
Behavior
Blank Meshing
Boundary Condition on points
Fluid Cell
Simulation methodology for Process setup Standard Forming
557
Simulation methodology for Gas Springs Specific Processes
777
Simulation methodology for Evaluation of the Standard Forming tool design
Simulation methodology for Specific Processes Simulation concepts Simulation methodology for Specific Processes
545
Optimization
706
Kinematics Springback measurement
200 725
ABOUT THIS DOCUMENT Attributes /Functionalities Chapters
USER’S GUIDE (released: Oct-12)
Cartesian kinematics Contact Cooling Channel
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Kinematics Contact and Friction Simulation methodology for HotForming
Simulation concepts Simulation concepts
200 175 609
Time Step & Increments EWK Rupture Model Drawbead
137
Drawbead Forces
Specific Processes Finite element and numerical models Finite element and numerical models Simulation concepts
Drawbead definition
Simulation concepts
Drawbead
237
DMP
Simulation concepts Simulation for Specific Processes
DMP Rollhemming
266 631
Simulation concepts
Kinematics
204
Rollhemming
631
Element elimination
Simulation for Specific Processes / Analysis tools /
368
Fluid Cell
Simulation concepts /
Solver analysis tools Fluid Cell
CPU Control Damage
Dynamic Freeze
Follower force
Force Freeze Gravity
Gluing Contact Kinematic Path Ironing
Mapping Mesh Multi body system
Optimization
ABOUT THIS DOCUMENT Attributes /Functionalities Chapters
Simulation concepts / Simulation for Specific Processes Simulation concepts Simulation concepts
Force & Pressure Rollhemming Force & Pressure Kinematics
Simulation methodology for Process setup Standard Forming Algorithms Finite element and numerical models Contact and Simulation concepts Simulation for Specific Processes Simulation for Specific Processes Simulation concepts Simulation methodology for Standard Forming Simulation concepts Simulation for Specific Processes Simulation for Specific Processes
Friction Rollhemming Simulation with Ironing-TTS Element Mapping process setup
59
237
209 207
206 203 557 45 175 631 774 311 557
Rigid Body Rollhemming
217
Optimization
706
631
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Path Definition Phase transformation Picking Press Force Analysis Pressure Quenching Refinement Rigid Body Robot Components
Simulation for Specific Processes Simulation for Numerical Models Simulation concepts
Rollhemming
631
Metallurgical material option Picking
163
Simulation methodology for Specific Processes Simulation concepts Simulation methodology for Specific Processes Simulation concepts
Press Force analysis Force & Pressure HotForming
760
Adaptive meshing Rigid body Rollhemming
264
Kinematics
200
Rotational kinematics
Simulation concepts Simulation for Specific Processes Simulation concepts
Solver Manager
Product startup
Springback
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Solver configuration
Simulation methodology for Springback measurement Specific Processes
261
206 590
217 631
32 725
Substructure
Substructure Simulation concepts Simulation methodology for Surface defect analysis Specific Processes
Symmetry Plane
Simulation concepts
Symmetry plane
259
Thermal properties
Thermal material option Hotforming
590
Process setup
557
User-Defined
Finite element and numerical models Simulation methodology for Specific Processes Simulation methodology for Standard Forming Simulation concepts
130
Values scaling
Simulation concepts
User Defined Attribute Picking
Trimming
303 504
261
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INTRODUCTION PAM-STAMP 2G OVERVIEW PAM-STAMP 2G is available as a ‘professional’ package. Essentially, it offers the user access to a significant number of options by using a flexible license ‘token’ approach. Included in PAM-STAMP 2G v2012:
PAM-STAMP INVERSE: for estimation of the developed part blank shape and very early feasibility studies on part.
PAM-DIEMAKER: for the design of the die
DELTAMESH: as meshing module
PAM-QUIKSTAMP: for feasibility analysis
PAM-AUTOSTAMP: for validation and optimization of sheet metal forming processes
PamStamp 2G v2012 proposes: the simulation of major sheet metal forming processes, like:
optimization and modification functionalities, like: Die compensation combined with surface reconstruction with iCapp PanelShop
Rollhemming
Hotforming
Super Plastic forming
Hydro forming
Blank and optimization
Tube forming
Morphing
The Stamp Toolkit enables the customization of all processes like Rubber pad forming or stretch forming.
Filleting with Deltamesh fillet Substructuring iterations
trim
for
line
local
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dedicated analysis tools, like
PAM-STAMP 2G 2012 © 2012 ESI Group
dedicated material models, like:
Cosmetic defect analysis
Corus Vegter material Model
Draw-in analysis
Matfem Crach material Model
Reporting tools
Yoshida material Model Ito-Goya material model Superplastic material models
Environment Common environment All modules proposed within PAMSTAMP 2G share the same environment. Switching between modules is easy and guided when necessary
Dedicated contexts Dedicated contexts are proposed for an automatic customization of the environment based on the selected process.
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Customized environment PamStamp 2G environment is fully customizable by company or by user. It can be adapted to the customer needs, by creating his own toolbars, process macro-commands, userdefined contours, or by defining the default parameters he wants to use.
PAM-INVERSE PAM-INVERSE is a one step or inverse solver, designed to make;
Developed part blank shape estimation for costing purposes.
Very early feasibility studies on PART geometry, prior to die design
Inverse solvers are designed to run very fast, but only to give 1st impression of component feasibility. Basic usage is to make 2 simulations to test the two extremes of material movement ‘free boundary’ and ‘locked’ boundary. In this sense it can be considered as a go / no-go gauge for component feasibility checking.
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PAM-STAMP 2G 2012 © 2012 ESI Group
PAM-DIEMAKER From an imported CAD geometry, PAM-DIEMAKER allows the user to design and optimize the binder surface and die addendum in just minutes. Its rapid and iterative parametric approach generates a realistic simulation model, allowing the user to quickly evaluate the part’s formability with QUIKSTAMP. Tipping direction, binder surface and addendum geometry can easily be modified, allowing total control of upfront design processes such as the number of stages and multi-parts grouping.
Highlights: Parametric modeling
PAM-DIEMAKER can be used starting from a CAD file of the part, with no tooling information available: the user constructs the die geometry from nothing by preparing the part geometry, by defining a binder surface and by constructing the run-off. In many cases, a new die design would be based on an already existing geometry. As such, it is much easier to just take this geometry as a reference and make the appropriate changes to certain zones rather than to entirely re-construct this die. The parametric re-engineering covers this latter methodology and allows the user to re-construct a parametric surface model in very short time. The reengineering starts from an existing die geometry (CAD or scanned data) and recreates the necessary surface information step-by-step, resulting in a 3D parametric model of the initial tool, that can e.g. be used to perform binder or run-off modifications or to exchange the part geometry.
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PAM-QUIKSTAMP Plus PAM-QUIKSTAMP allows the die designer to check and evaluate different die geometry parameters like binder surface and die addendum, including swages and die walls. PAM-QUIKSTAMP provides a fast formability evaluation, and represents the optimal compromise between accuracy, time and computing resources. Since PAM-QUIKSTAMP does not require high quality mesh for tools, it is very easy to iterate and optimize the process. Taking into account elasto-plastic behavior, friction, blankholder pressure, drawbead and cutting pattern, it carries out a fast and reliable 3D evaluation within minutes and eliminates erroneous choices at the conceptual design stage.
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PAM-AUTOSTAMP PAM-AUTOSTAMP allows the user to master virtual try-out of the stamping process taking into account the full process with industrial conditions such as gravity, binder development, multi-stage forming, draw, restrike, trimming, springback, flanging and hemming. PAM-AUTOSTAMP guides the user through the final validation of forming process, tolerances and overall quality control, helping to avoid costly and timeconsuming downstream problems. PAM-AUTOSTAMP also includes a state-of-the-art implicit solver technology, enabling fast accurate springback predictions. The scope of processes which could be modeled is continuously increasing, and includes hotforming, rollhemming, double blank forming, spot-welded blanks, rubberpad forming, super-plastic forming and multistage tube forming processes, in addition to the standard stamping, tube bending, tube and sheet hydroforming processes. Problems which can be detected include conventional formability issues of splits and wrinkles, but also subtle quality issues such as cosmetic defects, slip lines, marks, and dimensional stability after springback. Optimization tools help finding solutions to the detected problems. Blank or trim line optimization are useful for designing the correct initial blank shape and right trim lines, and Die compensation modifies automatically the die for reaching the good final shape after springback.
Courtesy of SKODA Auto
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PAM-TUBE PAM-TUBE INVERSE PAM-INVERSE offers a very fast simulation tool for non-critical bending operations and for general feasibility checks as a preforming step for hydroforming. An advisor is included that will determine if PAM-INVERSE is a suitable simulation method. With PAM-INVERSE bending operations of any circular, conical or user-defined profile can be simulated.
PAM-TUBEMAKER From an imported CAD geometry, PAM-TUBEMAKER allows the user to design and optimize the bending or hydroforming process in just minutes. Its rapid and iterative parametric approach generates a realistic simulation model, allowing the user to quickly evaluate the part’s formability. Process and tool design can easily be modified, allowing total control of upfront design processes such as the number of stages and multi-parts grouping. PAM-TUBEMAKER easily reads CAD data in IGES and VDA format. While reading the CAD surface information, it automatically meshes the surfaces as well using state of the art meshing technology from DeltaMESH. Next to the direct treatment of CAD surfaces, PAM-TUBEMAKER also imports various mesh formats, such as PAMSYSTEM, ‘universal (.unv)’ and ‘Nastran (.nas)’. On user interface level, PAM-TUBEMAKER tries to propose for the user process and tool design parameters by following as much as possible the objective of finding a feasible process setup. At the same time full flexibility is given, and the user has at all points the full control on the design.
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DELTAMESH The complete integration of DeltaMESH Stamping into PAM-STAMP 2G offers full functionality of automatic meshing within the software. With DeltaMESH meshing the user is certain to obtain a high quality mesh allowing to rapidly start the design process. As a good simulation result requires a good mesh, DeltaMESH will do just that: based on the initial CAD file, the program will automatically generate a connected mesh.
Fully automatic surface mesher integrated into the PAM-STAMP 2G environment that delivers high quality mesh results
Consecutive steps for import / joining / meshing can be handled automatically or interactively: o Reads IGES / VDA format o Joins surfaces with thin surface, hole, gap or overlap tolerance o Automatic meshing algorithms based on uniform, parametric and progressive meshing
Optional post-meshing operation: Automatic localized re-meshing according to some element quality criteria
DeltaMESH Fillet DeltaMESH Fillet integrated in PAM-STAMP 2G offers full functionality of automatic filleting. With DeltaMESH Fillet the user is certain to obtain a high quality fillet mesh on sharp edges allowing to start the process simulation as early as possible. Basically, good stamping simulation results require a good mesh on radii in order to accurately represent the metal flow phenomena and related physics. This will allow the user to control the global filleting and the local radii as well.
DeltaMESH Stamping Inverse This integration of DeltaMESH Stamping Inverse into PAM-STAMP 2G allows generating fully automatically a FEM quality mesh dedicated to the inverse method solver. The generation of this patch-independent mesh, consists in importing either a CAD model or a DeltaMESH geometrical database and joining it (topological model creation). DeltaMESH Stamping Inverse will create zones from connected face groups (for example, blankholder …). Thus, we obtain a mesh coarser than DeltaMESH Stamping mesh but with finite element quality
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Calculation Code PAM-STAMP2G is a calculation code that uses the finite element method (FEM). All the components of a calculation (metal sheet or tube, tools, …) are shown as meshes, i.e. a discrete representation of the geometry. For non-deformable tools, the mesh is only a representation of the geometry, and the finite elements are only facets to be used for contact description. On the contrary, for the blank, the tube or a deformable tool, the finite elements forming this mesh represent small pieces of the material with a prescribed behavior. The mechanical phenomena that occur in a blank or in a tube are faithfully reproduced using a large number of these elements. Within reason, the finer the mesh to be generated, the better the quality of the results, whereas the higher the number of elements, the longer the calculation time. Note that in a simulation, a detail whose size is smaller than that of the elements cannot be represented: the size of the elements defines the precision of the simulation. A finite element can be a 2-node (bar), a 3-node element (triangle), a 4-node element (quadrangle), a 6- or 8-node volume element (hexahedron), and it is constructed from nodes that are defined in its corners. Each node has two types of degrees of freedom: translation and rotation. The translation degree of freedom of a node represents its ability to move in translation along a direction, whereas a rotation degree of freedom of a node represents its ability to rotate about an axis. A node with three degrees of freedom in translation and three degrees of freedom in rotation can move along three axes – X, Y and Z – and can rotate about these three axes. Depending on the calculation type (implicit or explicit) the calculation is sub-divided into increments or timesteps. Generally, implicit increments are large with respect to the explicit timesteps. Positions, velocities, accelerations and forces are permanently calculated at the nodes, which are points linked to the material. Within the elements, strains are calculated from positions.
nodes element
mesh
Corresponding stresses are then obtained, which result in forces on the nodes. This calculation is repeated over all the elements for the entire duration of the calculation. Boundary conditions are used to remove degrees of freedom (locking), while velocities and forces further define the kinematic behavior of the finite element model. To describe the actual deformation process, material properties and thickness must be assigned to an element.
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PRODUCT START UP ASCII INPUT Purpose For all projects, the data set-up is stored in the .pre file of the project, which is a binary file. However, the application offers the user the possibility of having ASCII input files, enabling him to modify manually or automatically the data set-up without opening the GUI.
Data Input File The data set-up of a simulation is described with the attributes. The .att file is the ASCII file that contains the multistage data set-up that means the attributes of all the simulations that will be launched one after each other.
Writing of the file The .att file is automatically written when starting the simulation if the option Write the input file and start the calculation is activated.
It is also possible to write the .att file without running the simulation, with the option Write input file only. Default
·
By default the option Write the input file and start the calculation
is always activated.
PRODUCT START UP ASCII Input
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Simulation launching When the simulation is launched, if there are in the same project directory both the projectname.pre and a projectname.att files, the information of the .att file is transmitted to the solver instead of the information of the .pre file.
Data reading If there are in the same project directory both a projectname.pre and a projectname.att files, the information of the .att file is read instead of the information of the .pre file. The user can so modify manually the .att file and update then the .pre file by opening the project and saving it.
Mesh Input File The mesh used for a simulation is contained in the .pre file. However it is possible to write ASCII mesh input file (.mif).
Writing of the file The .mif file can be exported using the Export mesh menu with the mesh input file format (.mif). A name different from the project name can be given. The Mif format is as follow: -
The .mif file contains all the mesh needed by the solver to run a calculation (nodes, elements, 3D curves, objects, and picked restart files information).
-
The file is divided in sections starting by a keyword with DEF_ prefix, and ending by the start of another section or the end of the file. Each section can occur once in the file. The section can be associated to a parameter, which is the count of entities that are written in the section (to accelerate the loading time in allocating once the entities).
-
Within each section, several entries can be defined, with associated parameters (each parameter which is preceded by ‘/’ character).
-
Blank lines are authorized (i.e. lines without character or with space or tab characters).
-
Comment lines can be added, if they start with a ‘#’ character. They will not be read by the GUI nor the solver.
-
The lines must not exceed 256 characters.
Remarks:
·
The difference with the other export formats management is that not only the visible entities will be exported, but all the mesh, and that picking data will be exported also.
·
It is also possible to do a .mif export from a .res file.
PRODUCT START UP ASCII Input
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Simulation launching The launch of a simulation with a MIF file, is done by a command line using the .att file instead of the .pre file. The .att file must be modified to specify the mesh input file that the user wants to use for the simulation: After the section DEF_SOLVER, the following section has to be manually added: DEF_MODEL_INPUT_FILE FILENAME = ‘name of the .mif file to be used’
Data reading The results of the simulation will be loaded, when the user loads any of the result files. A .psp file is then automatically created. Note: ·
It is possible to import the mesh with the .mif format via the import mesh menu, using the options Keep identifiers and Keep thicknesses.
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CUSTOMIZATION The software allows the user to adapt the program to his needs, by creating his own toolbars and process macro-commands, or by easily defining the default parameters he wants to use. All such customizations are described in this chapter. Some of the customization data is stored in a separate configuration file (both in the installation directory and the main users’ directory) and can be manually modified. This is also further explained. Customization stored in the ‘users’ file, can be copied into the ‘installation’ file if you require specific ‘site’ customization, for example to implement standards across a company.
Toolbars It is possible for the user to create his own toolbars with the View / Toolbars / Customize option. This dialog box contains five tabs:
-
Commands:
All the options available for pre-processing, solver and post-processing are summarized according to their order in the Menu Bar. Individual tasks are chosen and added to the new user’s toolbar from this list.
-
Toolbars:
-
External tools:
-
Keyboard:
Default toolbars available in the program are listed. They can be activated or not. If activated, the toolbar tasks are shown in the upper part of a graphical window. If the user prefers to have icons of tasks coupled with text labels, the Show text labels option has to be activated too. New toolbars can be created, the options available in this toolbar must be chosen in the Commands list. These custom toolbars can be modified, renamed or deleted whenever necessary. This allows the user to define links from within the GUI to external software tools, for example a calculator, or a spreadsheet etc. This allows the user to define shortcut keys, which can be assigned to any action, making routine work more efficient.
PRODUCT START UP Customization
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Menu:
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It is used for the Menu Bar and a Context menus definition:
·
Menu Bar:
It can be chosen from several menu types (Curve Editor, Macro edit, etc.) specified for each kind of user’s work.
·
Context menu:
Four context menu options (2D Settings, 2D View, 3D View and FLD View) can be used. The 3D View Menu called "right-click" menu is automatically activated. Most of the options of this "right-click" menu are also accessible through the Menu Bar, but some of them can only be used through the former. New items can be added from the Commands list.
-
Positions: Enables
-
Options:
reset all windows and toolbar positions.
Enables defining some menu properties like displaying screen tips on toolbars, large icons, etc.
Advanced Mode Advanced mode currently is used to access the Stamp Tool Kit options. This function is generally designed to be used by the site Advanced User. If Advanced user mode is not activated, the Stamp Tool Kit options will not be available. It is possible to activate permanently the Advanced Mode in the Customize Macro page
Licenses It is possible to select here which options will be available; the corresponding tokens will be taken by the program. If the user does not have enough tokens, a message will be displayed in the console. The status of the Customize tokens menu is stored in the configuration file. If there are not enough tokens when launching the application with the saved license customize configuration, a message appears and the Customize tokens menu is opened. Warning:
·
The license configuration is saved when a user saves a new configuration in the general customize menu.
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PAM-STAMP 2G 2012 © 2012 ESI Group
Default Parameters The default parameters and settings proposed by the program can be defined for each user (user login). They are stored in the configuration file. The Customize / Options menu allows the user to specify the following parameters:
-
Design:
Default PAM-DIEMAKER and PAM-TUBEMAKER parameters can be defined in this page. See Simulation Methodology for Design and Stamping feasability and Simulation Methodology for Tube sections for further information.
-
DeltaMesh:
The Import, Joining, Meshing, Inverse meshing and Remeshing default parameters are defined here. The Meshing strategy can also be created and customized as default in this page. See Deltamesh section for further information.
-
Process: Default values of AutoStamp attributes are defined in the Process page. The Default unit system is also defined here, as the Check data before starting option
(It forces an attribute check to be done prior to launching the solver, giving the user the possibility to detect input errors without wasting solver time). Automatic Blank meshing can be deactivated here. See Blank editor chapter for further information. Parameters of Die compensation are defined on this page as well. Users, who want to use Tool editor before Blank editor in general workflow can deactivate Blank editor before Tool editor option through this page. -
Files location:
This page enables the user to define the default files location, especially when using Import Export and functionalities. It is also used when opening a Project or the Material Database. The Solver Host definition with the location of the executable used for the simulation as the eventual equivalences between disk names must be defined here.
-
GUI Parameters: All the default Display options are saved in this page, as the Camera movement and the 2D Section display. Reporting tools setting are defined here. The Activate ‘undo’ feature allows the user to activate the ‘undo’ function. By
PRODUCT START UP Customization
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default it is on. See User interface analysis tools chapter for further information. It is possible to define Search radius for Local Min/Max annotations here as well.
-
Geometry: In this page are saved the default values used for the mesh Orientation, for the Offset functionality and for the 3D curve editor. See offset chapter for further information.
-
Contours: Each contours option is by default activated or not in this page. See Contours chapter for further information. FLD contours options and Maximum angle on a face for Thickness of solids contour are defined on this page.
-
ToolEditor: Default Tool editor values are saved in this page. See the offset chapter for further information. Default initial blank mesh size (used if automatic meshing is not active) can be set here. See Blank editor chapter for further information. It is possible to define Flanging tool parameters on this page as well.
-
Macro: Process macro options are defined here. See Process macro chapter for further information.
Note :
·
Refer to the Reference manual for more detailed information on each functionality of the Custom options menu.
Customization File All of the above customizations are actually stored in an ASCII file that can reside in two locations. The main customization file is located within the installation directory and ensures general customization for all users. For more personalized customization the software also generates a customization file in the user’s main directory. For Windows it is: C:\Documents and Settings\
while on Unix this would be depending on the system that is used, e.g.: /usr/local/
The name of the personal configuration file is defined by default as stamp2G.cfg, but can be modified by the user. For Windows users, modifying the startup batch script that resides in the installation directory can do this. When starting the application, the main configuration file is read first, followed by the personal customization file. Any settings already defined by the main customization are overwritten by the personal customization file. The customization files are in ASCII format, so they can be read and modified by administrators if necessary.
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PAM-STAMP 2G 2012 © 2012 ESI Group
Macro-Command The software is able to automatically perform successive operations, which generally occur during the data setup of each step of a ‘standard’ simulation. These tools, thanks to which the user does not have to perform several manipulations during the data setup, are the macros. For ‘standard’ processes, nearly the whole data setup is performed by the process macro; therefore a full data setup can be done in a few minutes. Further explanations about the Stamp Tool Kit are given in the Process Macro and offset chapters of this document.
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FILES Numerous files are used by PAM-STAMP 2G. Each has a very precise function. Herein, the generic name of the project will be designated as “gn”.
Data Bases Material -
material.psm:
·
Material data.
·
ASCII files.
·
One file per material.
Macro from Stamp Tool Kit -
-
-
-
-
macro.ksa:
·
Definition of PAM-AUTOSTAMP standard forming macro.
·
ASCII file.
·
One file per process macro-command.
Macro.ksp
·
Definition of PAM-QUIKSTAMP Plus macro
·
ASCII file.
·
One file per process macro-command.
macro.ktf:
·
Definition of PAM-AUTOSTAMP tube hydroforming macro.
·
ASCII file.
·
One file per process macro-command.
macro.ktb:
·
Definition of PAM-AUTOSTAMP tube bending macro.
·
ASCII file.
·
One file per process macro-command.
macro.ksi:
·
Definition of PAM-INVERSE standard forming macro.
·
ASCII file.
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PAM-STAMP 2G 2012 © 2012 ESI Group
One file per process macro-command.
macro.kti:
·
Definition of PAM-INVERSE tube bending macro.
·
ASCII file.
·
One file per process macro-command.
Template from PAM-DIEMAKER -
-
profile.udt:
·
Definition of user-defined profile template.
·
ASCII file.
·
One file per profile.
profile.pfl:
·
Definition of parameters of standard profile template.
·
ASCII file.
·
One file per profile.
Project -
gn.psp:
·
Data common to all modules of the project (for example alarms, section planes, active state).
Preprocessor -
-
gn.pre:
·
Setting up of the project data and mesh description of the project.
·
Binary file.
·
Multistage file.
·
It is used to run a simulation.
gn.att:
·
Project data setup.
·
ASCII file.
·
Multistage file.
·
It can be used with the gn.pre file or with the gn.mif file to run the calculation.
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gn.mif:
·
Mesh description of the project.
·
ASCII file.
·
It can be used with the gn.att file to run the calculation.
gn.[i].und:
·
Temporary undo file that contains information for undo. If n undo are possible there are n files from gn.1.und to gn.n.und. Files are removed when closing the project.
·
Binary file.
·
Deleted when the project is closed.
CAD Meshing Module If the project comprises several modules, the following files correspond to the Ith module: -
-
-
-
-
-
gn.I.msh:
·
Definition of the CAD model, the elements, nodes and groups of the module.
·
Binary file.
gn.I.cmd:
·
Command file of DeltaMESH containing the input for meshing.
·
ASCII file.
gn.Ir.dtc:
·
DeltaMESH data base after import. Results of CAD import.
·
Binary file.
gn.Ia.dtc:
·
DeltaMESH data base after joining. Results of CAD joining.
·
Binary file.
gn.Im.dtc:
·
DeltaMESH data base after meshing. Results of CAD meshing.
·
Binary file.
gn.Im.fma:
·
Results of CAD meshing.
·
ASCII file.
·
PAM-STAMP 2G temporary file that can be imported.
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PAM-STAMP 2G 2012 © 2012 ESI Group
gn.I.his:
·
DeltaMESH Stamping messages file for all operations.
·
ASCII file.
Design Module (PAM-DIEMAKER and PAMTUBEMAKER) If the project comprises several modules, the following files correspond to the Jth module: -
-
-
-
-
-
-
-
gn.J.add:
·
Definition of the model used by PAM-DIEMAKER and PAM-TUBEMAKER (mesh, profiles, …).
·
Binary file.
gn.J.msh:
·
Definition of the CAD model, the elements, nodes and groups of the module.
·
Binary file.
gn.Jr.dtc:
·
DeltaMESH data base after import. Results of CAD import.
·
Binary file.
gn.Jm.dtc:
·
DeltaMESH data base after meshing. Results of CAD meshing.
·
Binary file.
gn.Jm.fma:
·
Results of CAD meshing.
·
ASCII file.
·
PAM-STAMP 2G temporary file that can be imported.
gn.J.trm:
·
Definition of the model used for Die Trimming.
·
ASCII file.
gn.J.ptl:
·
Definition of the user-defined PTL.
·
ASCII file.
gn.bending:
·
Definition of bending data.
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ASCII file.
Die Compensation -
-
-
-
-
-
-
Gn_Outifo.input:
·
Input file for Outifo containing the settings.
·
ASCII file.
Gn_Outifo.lis:
·
Output file of Outifo, containing all information about the computation. Used by the GUI in “Show all messages”
·
ASCII file.
Gn_Outifo.output:
·
Output file of Outifo containing the status of the computation. It can be seen in the GUI, in the Outifo console.
·
ASCII file.
Gn_Outifo.history:
·
History file written by Outifo, containing the points of Outifo history curves (max distance, average distance ….).
·
ASCII file.
Gn_Outifo.results:
·
Contours results of Outifo.
·
ASCII file.
Gn_linear.asc & Gn_linear_depla.asc:
·
Files used by the linear solver
·
ASCII file.
Linearsolver.LOG:
·
Output file of linear solver
·
ASCII file.
Substructure -
Gn.ini:
·
File containing the data stored from the main simulation (Id of node, position and Id of center of gravity). There is one file per stage.
·
Binary file.
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-
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PAM-STAMP 2G 2012 © 2012 ESI Group
Gn.S0i:
·
File containing the data stored from the main simulation (border node displacement). There is one file per stage.
·
Binary file.
Gn_ids.bf:
·
File used by the subrun simulation to do correspondence between node identification of main run and node identification of subrun. There is one file per stage.
·
Binary file.
Solver restart -
-
gn.irs: ·
input file to restart a calculation, contains the restart file identifier and possibly new calculation parameters
·
ASCII file
gn.[i].rst:
·
ith RESTART file written by the solver.
·
Binary file.
Warning:
·
-
When the maximum number of restart files is n, and the solver wants to write the (n + 1)th restart file, it will overwrite the first restart file, then overwrite the second, etc. Thus, the user should not just rely on the filename for identifying the most recent file, but look also for the progression value to which they correspond.
gn.[i].rst_P:
·
DMP calculation
·
ith RESTART file on the node P written by the solver. All these restart files per node must be located in the same physical disk space (be careful /home can correspond to different disk for each node of a cluster).
·
Binary file.
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Post-Processor -
-
-
-
-
-
-
-
-
gn.[i].res:
·
ith state file written by the solver, contains the results of a given state.
·
Binary file.
gn.end.res:
·
State file written by the solver at the end of the calculation.
·
Binary file.
gn.0.res:
·
Scanner state file written by the solver on user’s request during the calculation.
·
Binary file.
·
Temporary file.
gn.0[j].res:
·
Instant state file written by the solver on user’s request during the calculation.
·
Binary file.
·
Saved file.
gn.his:
·
History file written by the solver, contains the points of history curves.
·
Binary file.
·
The size depends on the number of points, on the number of entities stored and on the settings defined for history.
gn.out:
·
Solver listing.
·
ASCII file.
gn.err:
·
Solver messages. Written if the solver stops with an error message after cycle 0.
·
Binary file.
gn.msg:
·
Solver messages.
·
Binary file.
gn.qst:
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-
-
-
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·
Temporary status file that contains the request from the interface to the solver, for example when solver interaction is requested. File is removed after action is performed.
·
ASCII file.
·
Deleted when the solver reads the request.
gn.asw:
·
File which contains the answer of the solver to the request from the interface.
·
ASCII file.
gn_M01:
·
Mapping result file, contains requested data for computed model at end of calculation.
·
ASCII file.
gn.pda:
·
Post-processing data archive, contains modifications in post-processing stage with respect to main project file (created curves, modified objects etc.)
·
Binary file.
gn*.rib:
·
input files for the renderer (master file, model definition, lights definition, scene definition)
·
Binary files, except that the master file gn.rib is an ASCII file.
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Archiving a Project -
Pre-processor: ·
-
CAD meshing module, for each selected module: ·
-
-
gn.pre.
gn.I.msh.
Design Module, for each selected module: ·
gn.J.msh.
·
gn.J.add.
For the post-processor: ·
gn.1.res.
·
a few intermediate view files, for PAM-AUTOSTAMP projects.
·
gn.end.res.
·
gn.his, for PAM-AUTOSTAMP projects.
·
gn.err.
·
gn.out.
·
gn.msg.
·
gn.[i].rst : The restart file used for the picking of the next project, if
necessary, for PAM-AUTOSTAMP projects.
-
·
gn_M01, if available.
·
gn.pda.
Data common to all modules: ·
gn.psp.
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PAM-STAMP 2G 2012 © 2012 ESI Group
SOLVER MANAGER CONFIGURATION Introduction The solver manager is a daemon that runs on a calculation host. Its purpose is to wait for and then process the calculation requests sent by GUIs running on the same machine or on remote machines. The solver manager is a single executable file delivered with the standard installation. In the following, this executable file name is assumed to be solvermanager.exe.
Configuration Modes The solver manager can be configured either: -
by arguments in the command line used to launch the solver manager
-
by a configuration file
Configuration priority: -
the configuration file options redefine the default options.
-
the command line arguments redefine the configuration file options.
Warning:
·
On Windows systems, if the solver manager is started as a service (see the Solver Manager start chapter), no option can be set by the command line, except the log file path. The configuration file is then the only way to configure the solver manager for other options.
The configuration file read by the solver manager is either : -
the file specified by the -config argument in the command line used to launch the solver manager.
or -
a file named solvermanager.exe.cfg if no file was specified in the command line. This file must be located in the same directory as the solver manager.
The presence of a configuration file is not mandatory but if it is necessary, a default configuration file can be generated by typing the command: solvermanager.exe -genconfig [-config ]
The name of the generated file is solvermanager.exe.cfg if no filename is specified by the optional -config argument (.cfg is appended to the solver manager executable file name)
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Configuration File Description This is a default configuration file: ############################################################# ##
##
##
##
##
E S I
S O F T W A R E
##
##
##
##
##
############################################################# ############################################################# ##
##
##
##
##
SOLVER MANAGER CONFIGURATION FILE
##
##
##
##
##
############################################################# # ################################################## #
#
#
SERVER PARAMETERS
#
# #
################################################## # # SERVER_PORT
| 1201
# SERVER_PROTOCOL_VERSION | 2 # SERVER_LOG_FILE
|
# ################################################## # #
# SOLVER LAUNCHING PARAMETERS
#
# #
################################################## # # SCRIPT_TEMPLATE
|
# BATCH_COMMAND
| batch
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# LIBRARY_PATH
| NONE
# LIBRARY_VARIABLE
| DEFAULT
# MP_VARIABLE
| NONE
PAM-STAMP 2G 2012 © 2012 ESI Group
# ################################################## # #
# OTHER PARAMETERS
#
#
#
################################################## # # TEMP_DIRECTORY
| /usr/tmp
# SAVE_LAUNCH_SCRIPT
| NO
# SOURCE_PROFILE
| YES
# FORCE_AUTOMOUNT
| NO
# SCRIPT_CLEANUP_DELAY
| 5
A '#' character at the beginning of a line means that the line is commented and therefore ignored. To modify an option, the user must remove the '#' character and set the option value after the '|' character. An option value containing space characters must appear within double quotes.
Available Options The following items can be configured: Usage of a template for launch script generation [New in v2.2]
configuration file line
:
SCRIPT_TEMPLATE
|
command line argument :
-script
default value
no script template
:
is the path of a template file containing keywords that are replaced by the solver manager with the launch parameters received from the GUI. The filled template is then executed by the solver manager. If no template file is specified, the solver manager uses its own built-in template (same behavior than previous versions). This option is available on Unix/Linux systems only. See Defining a Template File for the Launch Script , below, for more details about defining a template file.
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Command used to launch a calculation in "batch" mode
configuration file line
:
BATCH_COMMAND
|
command line argument :
-batchcmd
default value
batch
:
is the name of the command used in batch mode to launch the solver. Name of the linked library path environment variable on Unix/Linux systems
configuration file line
:
LIBRARY_VARIABLE
|
command line argument :
-libvariable
default value
DEFAULT
:
can be an environment variable name (LD_LIBRARY_PATH for example) or a keyword: DEFAULT
: the environment variable name depends on the operating system:
-
IRIX
: LD_LIBRARY_PATH
-
HPUX
: SHLIB_PATH and LD_LIBRARY_PATH are both set
-
SOLARIS : LD_LIBRARY_PATH
-
AIX
-
DIGITAL : LD_LIBRARY_PATH
: LIBPATH and LD_LIBRARY_PATH are both set
Automatic setting of the linked library path environment variable on Unix/Linux systems
configuration file line
:
LIBRARY_PATH
|
command line argument :
-libpath
default value
NONE
:
can be a standard path (/usr/lib for example) or a keyword: NONE
:
do not set the library path environment variable
SOLVER_DIRECTORY
:
set the library path environment variable as the solver directory path
Automatic setting of the multi-processor environment variable
configuration file line
:
MP_VARIABLE
|
command line argument :
-mpvariable
default value
NONE
:
can be an environment variable name or a keyword: NONE
: do not set any environment variable
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DEFAULT
: set an environment variable whose name depends on the operating system:
-
IRIX
:
MP_SET_NUMTHREADS
-
HPUX
:
MP_NUMBER_OF_THREADS
-
SOLARIS :
PARALLEL
-
AIX
XLSMPOPTS='parthds...
-
DIGITAL :
:
MP_STACK_SIZE
Path and name of the solver manager log file
:
SERVER_LOG_FILE
command line argument :
-output
default value
blank (no file)
configuration file line
:
|
is the full name of the log file (eg: /usr/tmp/solvermanager.log) Port number on which the solver manager listens to requests
configuration file line
:
SERVER_PORT
command line argument :
-port
default value
1201
:
|
is the port number on which the solver manager listens to the requests. Version of the communication with the GUIs protocol
configuration file line
:
SERVER_PROTOCOL_VERSION
|
command line argument :
not available by command line
default value
depends on the version of the solver manager (2 for v2.2)
:
is a number from 1 to n. Note:
·
A GUI and a solver manager can always communicate whatever their version is (full compatibility). The user should never need to modify this option.
Path of the temporary directory
configuration file line
:
TEMP_DIRECTORY
command line argument :
-tmpdir
default value
/usr/tmp
:
|
is the path of the directory where the solver manager will write launch scripts
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Save the launch script generated by the solver manager
configuration file line
:
SAVE_LAUNCH_SCRIPT
command line argument :
-savelaunchscript
default value
NO
:
|
YES / NO
When this option is enabled, the launch script generated by the solver manager in its temporary directory is not deleted once the solver is launched but renamed to smgr_launch_script. This allows for example to check / modify this script and restart it in a console to track a launch problem. Note that all scripts are renamed to the same name; it is advised to work with a copy of smgr_launch_script which will be overwritten by subsequent launches. Enable the sourcing of profiles files (sh and ksh environments)
configuration file line
:
SOURCE_PROFILE
command line argument :
-nosourceprofile
default value
YES
:
|
YES / NO
When this option is disabled, the launch script generated by the solver manager will not include execution of /etc/.profile and $HOME/.profile files. This can be useful if these files contain instructions that make the launch fail. Force automount before entering directories [New in v2.2]
:
FORCE_AUTOMOUNT
command line argument :
-forceautomount
default value
NO
configuration file line
:
|
YES / NO
When this option is enabled, the solver manager calls some “list directory” commands to trigger automount of some directories before trying to enter them (just entering a directory might not trigger automount on old systems). This option should not be activated if no problem occurs with automount. Delay before deleting scripts [New in v2.2]
configuration file line
:
SCRIPT_CLEANUP_DELAY
|
command line argument :
-scriptcleanupdelay
default value
5 (seconds)
:
This option allows defining the delay (in seconds) before the solver manager deletes a script it has just launched.
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PAM-STAMP 2G 2012 © 2012 ESI Group
Defining a Template File for the Launch Script This option is available on Unix/Linux systems only. A template file is a text file that can be located anywhere. It can contain keywords that are replaced by the solver manager with the launch parameters received from the GUI. To enable the usage of a template file, define its path in the solver manager’s configuration file or in the solver manager’s command line or simply copy it in the same directory than solvermanager.exe and name it solvermanager_script.tpl (this is the default name for templates) A default template file, very close to the built-in script, can be generated by the command: solvermanager.exe –genscript [-script ]
This is an example of a template file (the keywords that will be replaced by the solver manager are highlighted in this example): #!/bin/sh case $SHELL in /bin/sh | /bin/ksh | /bin/bsh ) if [ -f /etc/profile ] ; then $SHELL /etc/profile fi if [ -f $HOME/.profile ] ; then $SHELL $HOME/.profile fi ;; /bin/bash ) if [ -f /etc/profile ] ; then $SHELL /etc/profile fi if [ -f $HOME/.bash_profile ] ; then $SHELL $HOME/.bash_profile fi ;; esac # --- Enter work directory cd $PAMPARAM_WORKDIR # --- Set environment variables
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PAMPARAM_VAR1_LABEL="PAMPARAM_VAR1_VALUE";export PAMPARAM_VAR1_LABEL PAMPARAM_VAR2_LABEL="PAMPARAM_VAR2_VALUE";export PAMPARAM_VAR2_LABEL PAMPARAM_VAR3_LABEL="PAMPARAM_VAR3_VALUE";export PAMPARAM_VAR3_LABEL PAMPARAM_VAR4_LABEL="PAMPARAM_VAR4_VALUE";export PAMPARAM_VAR4_LABEL PAMPARAM_VAR5_LABEL="PAMPARAM_VAR5_VALUE";export PAMPARAM_VAR5_LABEL # --- Run the command nohup $PAMPARAM_CMDLINE > $PAMPARAM_OUTPUT # --- Normal termination exit 0 Note:
·
If a keyword is preceded by a ‘$’ character, this ‘$’ character will also be removed by the solver manager. This allows writing a template file, based on environment variables, that could also be directly executed from a terminal or from another script, just by setting the environment variables corresponding to the keywords before calling the script (for testing...)
Example:
setenv PAMPARAM_WORKDIR
/usr/temp
setenv PAMPARAM_CMDLINE ls setenv PAMPARAM_OUTPUT ls.out ./solvermanager_script.tpl
The keywords that are accepted in this version are: - PAMPARAM_WORKDIR :
work directory of the calculation
- PAMPARAM_CMDLINE :
full command line that launches the solver
- PAMPARAM_OUTPUT
:
file where solver output must be written
- PAMPARAM_NBPROC
:
number of processors requested for the calculation
- PAMPARAM_RUNMODE :
launch mode (0 for immediate, 1 for batch)
- PAMPARAM_USER
:
name of the user which sent the calculation request
- PAMPARAM_SHELL
:
user’s shell (/bin/sh, /bin/csh, ...), equivalent to system’s $SHELL
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PAM-STAMP 2G 2012 © 2012 ESI Group
SOLVER MANAGER START The solver manager is a single executable file that is launched differently according to the host operating system.
On Unix/Linux Systems Start the solver manager from a term window: -
logon as the root user
-
type the command: cd
where is the directory where the solver manager executable file is located. -
type the command: nohup solvermanager.exe [-output ] > /dev/null &
where is the full path of the solver manager log file (/usr/tmp/solvermanager.out for example) The –output argument is optional (the user can also define the log file path in a configuration file). If the user does define any log file path, no solver manager messages will be stored or displayed.
Start the solver manager at boot time: -
locate in the system the script file whose purpose is to start the daemons at boot time (consult the system administrator)
-
insert the following command in this file: /solvermanager.exe [-output ] > /dev/null &
where is the full path of the solver manager executable file directory and is the full path of the solver manager log file (/usr/tmp/solvermanager.out for example) The –output argument is optional (the user can also define the log file path in a configuration file). If the user does define any log file path, no solver manager messages will be stored or displayed.
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USER’S GUIDE (released: Oct-12)
On Windows Systems The solver manager is normally installed as a service and launched by the installation tool. This is however the procedure to install and/or launch it manually.
Start the solver manager from a command window: -
type the command: cd
where is the directory where the solver manager executable file is located. -
type the command: solvermanager.exe –noservice -output
where is the full path of the solver manager log file (/usr/tmp/solvermanager.out for example) The –output argument is optional (the user can also define the log file path in a configuration file). If the user does not add it to the command line and no log file is specified in a configuration file, the solver manager messages will be displayed in the command window. Warning:
·
If the user starts the solver manager from a command window, all the calculations launched by the solver manager will be attached to the user account the user is logged on. Therefore, these calculations will be killed by the system when the user closes his session.
Start the solver manager as a Windows service: A specific user account must have been created with the “log on as a service” privilege. This account is named pamservice in the following. The pamservice account will be assigned to the solver manager service so that the calculations launched by the solver manager are also attached to this account. This prevents the calculations from being killed when a session is closed (assuming that the pamservice account is reserved to calculations and that nobody logs on this account). Note that the calculations are attached to pamservice, not to the user that requests the calculation. This must be taken into account, particularly for network access settings. This is the procedure to install and start the solver manager as a service: -
open a command window
-
type the command: cd
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PAM-STAMP 2G 2012 © 2012 ESI Group
where is the directory where the solver manager executable file is located. -
type the command: solvermanager.exe –service –user pamservice
-
enter the password of pamservice
If another solver manager service is installed and is running (whatever its version is), this service is first stopped and removed before installing and starting the new one. If no configuration file is present or if the log file is not specified in this configuration file, the solver manager messages will be saved in a default log file. This default log file is located in user profile directory and it is named solvermanager.out. More generally, the user cannot configure the solver manager by command line arguments if the he starts it as a service, except the log file path. If the user needs to modify some other options, he must generate a configuration file and set the options inside it (see the Solver Manager Configuration chapter).
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SOLVER MANAGER ACTIVITY If the user has defined a log file path when starting the solver manager (in the command line or in the configuration file), he can read in this file a processing report of all the requests received by the solver manager. Example of log file: ### 12/03/2003
13:57:58 : Starting the solver manager...
-> Solver manager started (Version 2.2 Protocol v2) [ Copyright ESI GROUP 2007 ] -> Waiting for requests on port 1201... ### 12/03/2003
13:58:45 : Request received from 'remote GUI'
-> Processing script... + Action requested
: Start a calculation
+ User name
: 'user1'
+ Executable path
: '/usr/local/bin/solver.exe'
+ Command line
: '/usr/local/bin/solver.exe -if "test.pre"'
+ Work directory
: '/usr/projects/'
+ Output file
: 'test.out'
+ Nb of processors
: 1
+ Execute action immediately -> Setting work directory
: OK
-> Script template loaded
: OK (solvermanager_script.tpl)
-> Writing script
: OK
-> Creating output file
: OK
-> Creating the process
: OK
The lines beginning with ‘###’ report the solver manager start-up and termination and the date and origin of all the requests. The lines beginning with ‘+’ describe the requests. The lines beginning with ‘->’ report the solver manager actions and the result (success or failure with error message) of these actions. Moreover, version 2.0 and later of the solver manager sends a full report to the GUI so that a clear message can be displayed in the GUI to inform the user about the success or failure of his request (and the reason it failed if necessary).
PRODUCT START UP Solver Manager Activity
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CALCULATION STOP A calculation should normally be stopped by the GUI so that the process can cleanly terminate (writing of restart files…), using the solver/stop option.
The user might however need to kill the calculation process because it does not respond anymore, he does not need a clean termination or because he does not want to use the GUI. On Unix/Linux systems, the user can use the system command kill provided if the he has the right to kill the process. If the user is not logged on the calculation account (or he is not the super user), he will have to switch to the calculation account before. On Windows systems, the user can use the task manager provided if he has the right to kill the process. If the solver manager is running as a service with a different account than the one he is logged on, he will not have the right to kill the calculation because it is attached to the service account. In this case, the solver manager executable file must be used to send a kill request to the running solver manager. This is the procedure: -
get the process id of the calculation (get it from the task manager window)
-
open a command window
-
go to the solver manager executable file directory
-
type the following command: solvermanager.exe –killpid [-port ]
where is the process id of the calculation and is the port number on which the solver manager listens to requests. Note:
·
–port is optional. If it is not specified, the default port is used.
This procedure is not available on Unix/Linux systems.
PRODUCT START UP Calculation Stop
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FINITE ELEMENT AND NUMERICAL MODELS ALGORITHM Explicit, Implicit and Advanced Implicit Algorithms Algorithms used by the solver of numerical simulation, work step-by-step in order to find dynamic equilibrium at each step. Different types of algorithms can be used: explicit, implicit and advanced implicit. The main differences are highlighted through this section and a comparison table at the end of the section summarizes it all. The principle of the explicit and the implicit time integration of a 1D system with one degree of freedom can be represented by a linear spring system:
k
m
c f(t),x,v,a
A linear damped spring system The equilibrium equation of the spring system is: m.an c.vn k.xn f n ,
where n means the time increment.
Explicit In the explicit method, the nodal velocities are written down at times tn-1/2, tn+1/2 and nodal displacements and accelerations at times tn-1, tn, tn+1. At time tn the nodal displacement xn is known and the acceleration an is computed from the internal and external forces. Nodal velocity vn-1/2, is known at time tn-1/2. The algorithm searches for the nodal velocity vn+1/2 at time tn+1/2 and the nodal displacement xn+1 at time tn+1. The application of the central difference method gives nodal velocity at time tn+1/2 and the nodal displacement at time tn+1 (assuming that Tn is small):
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m
an an
1
. (f n
t k . x n
)
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in case of no damping applied.
V 1 V 1 n n 2
2
( T T ) / 2 n -1 n
V 1 n
X n 1 X n T n
2
For complex processes (other than 1D system) m is a matrix, it is diagonal and can be immediately calculated without any matrix inversion. Unfortunately, this method is stable only if a small time step Tn is used (see TimeStep & Increments)
Implicit Purpose Stamping simulations are considered as static, using an incremental method (based on loading or tool kinematics). The dynamic effects are neglected, the velocity and the acceleration are set to zero.
Calculation of each increment Within one increment, (see TimeStep & Increments) the solver automatically tries to find the solution of a set of nonlinear equations, using linear iterations, also known as Newton iterations, with convergence criteria. Newton iterations: F(u)=Fext (Fext=0 in springback case) F(u)=F(0) + F/u(0) u
u1=K-1(0)(Fext-F(0)) u1= u1
F(u)=F(u1) + F/u(u1) u
u2=K-1(u1)(Fext-F(u1)) u2= u1+ u2
So un= u1+ u2 +…+ un, the displacement convergence is reached when |un|/Max(|ui|)Surface->Convert into NURBS
IGES interface parameters To export a thinkdesign model into IGES format that could be imported by DeltaMESH, the IGES options must be customized. To export in IGES format, select Save as in the File menu. The following dialog will appear:
thinkdesign: the Save as dialog box
Choose the .igs option in the Type drop-down list, and click the Options button. The following dialog box will appear.
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thinkdesign: the Advanced IGES options dialog box (DeltaMESH’s recommended values)
Select Settings->Save->Advanced. There are 4 parameters that must be set as follow (see the figure above): -
Split closed faces/surfaces:
OFF
-
Map rational to not rational:
OFF
-
Map 143:0 to 144:0:
ON
-
Convert to NURBS
– Arcs:
ON
After that, click the Settings button and save the new settings as the deltamesh settings.
VDA interface parameters The VDA output parameters are defined in the VDA Options dialog box available by choosing the VDA type in the Save as dialog.
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thinkdesign: the Advanced VDA options dialog (DeltaMESH’s recommended values)
The default value can be used to export into the VDA format, a format dedicated to DeltaMESH.
Preparation of geometry in UNIGRAPHICS Definition and verification of the geometric model Refer to the general recommendations in subsections “Description of the CAD Model” and “Interpreted CAD Entities”.
IGES interface parameters The types of transfer of UNIGRAPHICS entities to IGES are defined by selecting option 10 of the Preprocessing Options menu. The Preprocessor Entity Mapping menu is then displayed. To choose the different types of entities, the following options must be selected (“...” means the choice has no importance) : 1. Crosshatching
TO
...
2. Cone
TO
B-Surface
3. Cylinder
TO
B-Surface
4. Sphere
TO
B-Surface
5. Surface of Revolution
TO
B-Surface
6. Tabulated Cylinder
TO
B-Surface
7. Trimmed Surface
TO
Trimmed surface
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8. Periodic Surface
TO
Split Surfaces
9. Solid/Sheet Body
TO
Ungrouped geometry
10. Assembly
TO
...
11. Pattern
TO
...
12. UG Line Font
TO
...
13. UG Color Definition
TO
...
The types of surfacic entities to transfer are defined by selecting option 2 of the Entity Selection menu. The Select Surfaces menu is then displayed, and the following options must be selected: 1. Cylinder
ON
2. Cone
ON
3. Spheres
ON
4. Surface of Revolution
ON
5. Tabulated Cylinder
ON
6. Bounded Planes
ON
7. B-Surfaces
ON
8. Planes
OFF (1)
9. Offset Surfaces
ON (2)
10. All 11. None
(3)
Notes:
(1) “Isolated planes” must be replaced by standard B-surfaces. (2) We recommend replacing Offset surfaces by standard B-Surfaces. (3) If you only want to transfer curves into the IGES file (e.g. for drawbead lines), you must select None to set all the surface types to OFF. The types of curve entities to transfer are defined by selecting option 1 of the Entity Selection menu. The Select Curves menu is then displayed. The following options must be selected: 1. Points
OFF
2. Lines
ON
3. Arcs
ON
4. Conics
ON
5. B-Curves
ON
6. Solid Edges on Drawings OFF
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7. All Solid Edges
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OFF
8. All 9. None
(1)
Note:
(1) If you only want to transfer surfaces into the IGES file, select None to set all the curve types to OFF.
Preparation of geometry in Rhinoceros Definition and verification of the geometric model Refer to the general recommendations in subsections “Description of the CAD Model” and “Interpreted CAD Entities”. Before the transfer, it is recommended to check if the model is “clean”. The tool is available in the Analyze -> Diagnostics -> Check menu (for more details refer to Rhinoceros documentation).
IGES interface parameters In order to proceed to an IGES export document (only the geometry is saved) select File -> Save as… from the menu. The Save as dialog box is displayed. You can specify the name of the iges file that will be created and set the .igs extension in the Save as type field. After, click on the Save button, you must customize the IGES export options (Edit Types button) (see the following figure) or select the right IGES type if you ever have saved it.
Rhino IGES Export detailed option dialog box
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The IGES tolerance: In general, it should match the absolute tolerance setting in Rhino, taking into account the possible unit conversion. To create a new IGES export type, Click on the New… button, set the following option and click Close:
Rhino IGES Export dialog box (DeltaMESH’s recommended values)
General: -
IGES version:
5.3
-
Text file type:
CRFL (MS-DOS, Windows) or LF (UNIX).
DeltaMESH reads indifferently both types of files on all platforms.
Rhino IGES Export dialog box (DeltaMESH’s recommended values)
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Points and Curves: -
Point objects:
106-2 (Layer point sets)
-
Max degree: performance but other values are admissible.
3 is recommended for better
-
Composite curves as single B-spline:
NO
-
Use simple entities when possible:
NO
-
Fit rational curves:
YES
-
Clamp end knots:
YES
Rhino IGES Export dialog box (DeltaMESH’s recommended values)
Surfaces: -
Solids:
402-7 (Unordered group).
-
Polysurfaces:
Separate surfaces
-
Surfaces:
144
-
Use simple entities when possible:
NO
-
Fit rational surfaces:
NO
-
Clamp end knots:
YES
-
Split closed surfaces:
YES
-
Split bipolar surfaces:
YES
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Rhino IGES Export dialog box (DeltaMESH’s recommended values)
VDA interface parameters No parameters are required for DeltaMESH (see subsection “List of VDA entities interpreted by DeltaMESH”).
Rhino VDA Export dialog box
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MESHING ACCESS Standard mode To start a session, first check that the CAD files are available, and then start the application. Create a project by selecting New -> Project in the Project menu, or by clicking the button. To access DeltaMESH direct import dialog: -
click the
-
or click the
button in the Data set-up dialog box in an active DeltaMESH module button in the 3D window meshing module and select import CAD
(direct)
-
or click the button in the 3D window setup module and select import tools CAD (automatic transfer to setup module)
-
or click the
button in the 3D window setup module and select import CAD for (automatic transfer to design module).
reengineering or import CAD
Figure 6: DeltaMESH direct import window
Import, joining and meshing are executed by clicking the Import & Transfer or Import & Check button.
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Import & Check: saves and opens a DeltaMESH module. Import & Transfer: transfers directly the mesh to the setup or a design module without any possibility of correction of the topological information and mesh except if Backup in DeltaMESH module is activated. The geometry, the topological information and the mesh are saved in a DeltaMESH module. It allows the user to return to the module for any modifications keeping geometry, topological information or a part of the mesh. See advanced mode section for more information. Two parameters are available: -
Size:
It is a factor size used to adapt mesh size to the part. The value depends on the unit used in the CAD file and the size of the model. The default value is 1, corresponding to a part size between 1 and 4 meters with millimeter as unit.
-
Strategy:
4 strategies included all meshing parameters are pre-defined, corresponding to the use of the solver. Feasibility
Validation
Springback
Algorithm
Parametric
Minimum element size
0.1 x Size
Maximum element size
30 x Size
30 x Size
30x Size
Chordal error active
YES
Chordal error follow iso
YES
Chordal error max distance
0.15 x Size
0.15 x Size
YES
Angle criteria follow iso
NO 15.
15.
Follow borders
10 x Size
0.1 x Size
Angle criteria active
Angle criteria max angle
Die compensation
0.1 x Size
7.5
7.5
YES
It is possible to add user defined strategies. Import and Joining default parameters are used. Refer to the Parameters chapter for more details about parameters. The transfer menu from DeltaMESH module appears by a left-click on the the 3D window.
button in
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It is possible to: -
transfer the DeltaMESH module's mesh to the Setup (pre-processing) or to the Design module
-
update an existing module with the DeltaMESH module's mesh
-
edit transfer rules
Advanced mode DeltaMESH Module A meshing session is started either by creating a DeltaMESH module or by activating a previously created module. The list of created modules is present in the Meshing tree of the Project tab. -
To create a new DeltaMESH module, select New -> DeltaMESH Module in the Project menu or select Add DeltaMESH module in the Meshing right-click menu.
In the Creation of new DeltaMESH module dialog, enter the project name. -
To activate a previously created DeltaMESH module, double-click its name in the explorer window.
A DeltaMESH module contains the geometry, the topological information and the mesh for a specific part. To access DeltaMESH advanced mode; select DeltaMESH -> Tool meshing… in the menu, click the button in the Data set-up dialog box or click the button in the 3D window meshing module and select import CAD (advanced). Geometry
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If for a single part you need to store several strategies for importing the geometry, joining and meshing, you must create several CAD modules. A contextual menu can also appear by a right-click on the CAD module label. Several options can be reached.
It is possible to: -
activate a previous created module using Set as active module option (you can also double-click on its name)
-
rename a previous created module with the Rename option,
-
copy all or part of a module (Geometry, Topology, Mesh) into a new CAD module using the Save as option,
-
delete a previous created module using the Remove option.
The transfer menu appears by a left-click on
button in the 3D window.
It is possible to: -
transfer the DeltaMESH module's mesh to the Setup (pre-processing) or to the Design module
-
update an existing module with the DeltaMESH module's mesh
-
edit transfer rules
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DELTAMESH PARAMETERS All parameters presented are available in the advanced mode. They are also used to define default strategy adapted to the type of user’s part, to complete or to correct a model. The work is divided into three stages: -
Import
-
Joining
-
Meshing
The three steps can be defined and run separately or jointly. We recommend you to check each step and examine the output report displayed in the DeltaMESH console. You can also access a more detailed report by clicking the repair chapter for more details)
button (see Check &
Import Presentation In this stage the geometrical model is constructed from one or more CAD files in IGES or VDA. Note:
·
We can also import an existing PAM-STAMP 2G geometrical database generated from CAAV5 and proceed directly to the other steps (joining and meshing).
The CAD files can be imported one by one, or in groups. In all cases, the files must be imported before the joining phase. Each CAD file will be imported and "cleaned" depending on the following characteristics: -
the import tolerance of the CAD file,
-
which representation for faces boundaries was used when creating CAD file,
-
which geometry to mesh (surfaces and/or curves),
-
how the faces groups were defined when creating CAD file?
Depending on the import tolerance's value, DeltaMESH constructs a geometric model using the following rules: -
surfaces and/or curves smaller than the tolerance are eliminated,
-
curves smaller than the tolerance are eliminated from the contours of the corresponding surfaces,
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successive tangent curves along a surface's contour are concatenated to form longer curves,
-
surface contours are closed.
Elements will be grouped afterwards according to the created surface or curve groups. Notes:
·
All the previous recommendations are not necessary for the PAM-STAMP 2G geometrical format (*r.dtc file) because these recommendations are already included in this format.
·
The r.dtc file can be obtained either from PAM-STAMP 2G or directly from CAAv5.
Definition of Import Parameters To access the import parameters, the user must select a CAD file in the Meshing dialogue box. Then the Import dialog appears where you can choose three different formats of CAD file: Iges (.igs), Vda (.vda), or Deltamesh database (r.dtc). The dialog detects automatically the extension.
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OR
After clicking the Open button, the Import parameters dialog appears, where you can set various parameters that will influence the importation of CAD File: -
Tolerance:
Defines the tolerance value for reading the CAD file (default value: 0.1). The tolerance value must be expressed in the length unit used in the CAD file. It must be positive and its minimum value permitted by DeltaMESH depends on the precision defined by the configuration parameter Reference space (see subsection Model panel).
Notes:
·
The value of the tolerance used must be about the 10th of the size of the details to represent (example: 0.1mm to represent details of 1mm).
·
The smaller the value of the tolerance, the higher the precision of the geometry, but longer the geometrical processing.
-
Read IGES blanked entities:
This option is used to import or not blanked entities defined in the IGES files. This parameter can be very useful with Catia v4 IGES file, because it allows the user to filter entities present into the NO SHOW. If you deactivate this parameter, the blanked entities (entities that belong to the NO SHOW) will not be imported. By default, this toggle is activated.
-
Prefer 3D boundaries:
In IGES standard, a trimming curve entity (number 142) used to describe surface boundaries, is defined both by its “3D representation” and by its “2D parametric representation”. In certain IGES file, these two curves representations are inconsistent. This results in gaps between surfaces that are not visible in the CAD software. In fact, this problem is a translation error that occurs during IGES file creation. It happens only with a few translators. The choice between these two representations cannot be done automatically by DeltaMESH (by default, it uses the “2D parametric representation”). Only the user can choose.
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If this toggle is activated, the 3D boundary definition of faces will be preferred to the other one. By default, this toggle is deactivated. -
IGES preferred representation:
This functionality allows DeltaMESH choosing automatically the better representation of the surface boundaries. When the surface boundary representations in the 2D and 3D space are inconsistent (see more precise explanations in the Prefer 3D boundaries definition), DeltaMESH will make some projection tests to choose automatically the better representation to avoid a gap. By default, this toggle is deactivated.
-
Surfaces:
-
3D Curves:
-
Entities:
-
IGES Level:
-
IGES Color:
This option is used to mesh a surfacic model and to generate triangular and quadrangular elements (activated by default). This option can be activated/deactivated simultaneously with 3D Curves option. This option is used to mesh curves and to generate bar elements (deactivated by default). This option can be activated/deactivated simultaneously with Surfaces option. This option takes (or not) into account the predefined groups in the CAD file (IGES 402 FORM 7; VDA Group) (activated by default); and can be activated/deactivated simultaneously with IGES Level and IGES Color options. Some CAD software do not generate IGES group entities but use the Level and/or Color fields in IGES entities definition for group representation (often seen as “layers” in the content of a CAD system). If this check box is activated, the groups predefined by the Level field (5th field of IGES entity) will be read (deactivated by default). If this check box is activated, the groups predefined by the Color field (13th field of IGES entity) will be read (deactivated by default).
Click the Set button to apply the parameter setting to the chosen CAD file. The parameter setting of each CAD file can be updated afterwards by double clicking Parameters zone in the Import tab of the Meshing dialog box. Click the Apply button to launch the DeltaMESH import session. The order of CAD file importing is defined by the order in which the files are chosen. If importing takes place in several stages, the application will ask whether to Complete the model (add the geometry contained in the imported files), or to Delete the existing model (the existing geometry will be replaced by the geometry contained in the imported files).
Remarks on Importing Files and Groups The CAD files must have the following suffixes to be imported by DeltaMESH: -
.igs (in lower case) for IGES files,
-
.vda (in lower case) for VDA files,
-
*r.dtc (in lower case) for DeltaMESH geometrical database
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It is possible to mix several types of CAD form in an import operation, e.g.: -
the blank holder surface in VDA format,
-
the die entry fillet in UNISURF format,
-
the rest (“die bottom”) in IGES format.
Note:
·
This capability is useful when it has proved impossible to transfer surfaces via a CAD interface (e.g. IGES). Simply select these surfaces in the CAD system and generate a file using another format (e.g. VDA). DeltaMESH can then import this new file, by adding it to the previously imported geometric model.
Each time an import operation is executed, DeltaMESH creates one or more new objects containing groups of surfaces and/or curves, depending on the number of “group entities” defined in the file (see subsection “Definition of the areas”). For groups containing other groups, only the highest level groups will be recognized by DeltaMESH. If the CAD file contains surfaces and/or curves not belonging to any group, DeltaMESH creates one new group formed by the “independent surfaces” and another new group formed by the “independent 3D curves”. This action is indicated in the output file by the sentences: “25 patch(es) replaced by bounded faces” and “Faces group number 2 created”. We recommend you use different files for surfaces (that define tools) and for 3D curves (that define drawbead lines, cutting curves, …).
Joining Presentation In this phase, a topological model is automatically constructed from the geometrical model created beforehand in the CAD file import phase. The joining means “reattaching” surfaces and curves to obtain a continuous geometric model. After this phase, most of the gaps and overlaps between surfaces and/or curves will be eliminated automatically according to the values of the following two parameters: -
Joining tolerance:
This is the maximum permitted reattachment distance (gaps or overlaps greater than this value will remain) that will be taken into account during the first joining step.
-
Minimum Feature size:
This is the minimal size of the geometrical details that will not be deleted during the joining session. All the geometrical details smaller than this value will be erased.
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Definition of Joining Parameters To access joining parameters, the user has just to click the joining tab of the Meshing dialog. This operation can be divided into two parts: -
Create the topological model
-
Complete an existing topological model
Topological model creation
In general, for the first joining session, it is recommended to activate the Apply to all objects option. All surfaces and 3D curves, if any, will be joined (the surfaces together and the 3D curves together). The joining parameters must then be specified, i.e.: -
Joining tolerance: (default value: 0.1
Minimal absolute joining tolerance used during joining session mm). This value is used during the first step (invisible for the user). This parameter makes it possible to join generally 90% of the geometrical model without any degeneration of the latter. This value must not be too high in order to keep the maximum details for the next operations.
-
Minimum Feature size:
This is the minimal size of the geometrical details that will not be deleted during the joining session. This value is used to join the remaining free edges of the first step which the reattachment distance is lower than this value Beyond this distance the sides of two surfaces will not be reattached (default value: 0.5 mm),
-
Automatic deletion of thin surfaces:
This toggle makes it possible to activate/deactivate the elimination of the thin surfaces and the correction of
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erroneous faces which present a thin zone that could induce a bad quality mesh. A face is considered as a thin surface if its width is smaller than the “Maximal width” value (default: activated, value: 0.25 mm). -
Automatic deletion of duplicated surfaces: This
toggle permits to activate/deactivate the detection and the elimination of the duplicated surfaces (default: activated).
-
Automatic deletion of geometrical overlaps:
-
Automatic holes filling: This toggle permits to detect or not the geometrical holes according to the “maximal diameter” parameter value and to fill these holes by the
This toggle allows to activate/deactivate the detection and the elimination of the overlaps according to the “maximum gap” parameter value (default: activated).
creation of faces. Warning: only “planned” holes can be filled without any degeneration of the geometry. This toggle is deactivated by default. The joining session proceeds to a first joining with a very low joining value (0.1 by default). This step is invisible for the user but makes it possible to join 90% of the geometrical model and to prepare the topological model for the detection and the elimination of the thin surfaces. The joining operations will: -
reattach the faces to obtain a continuous geometrical model,
-
automatically repair the faces that present a very thin zone (see the Figure 2)
DeltaMESH detects the thin zone on the face. In the past, these zones generated multiple edges after the joining session.
With the new algorithm, DeltaMESH corrects the poor quality face and avoids the creation of multiple edges.
Figure 2: Automatic treatment of surface with thin zones
-
detect and eliminate thin surfaces
For the elimination of the thin surfaces, DeltaMESH uses the value of the Maximal width parameter. This parameter permits to complete the joining results obtained during the first step and to detect and to eliminate the thin surfaces. The main advantage of this functionality is to improve locally the mesh quality by eliminating the source of very small elements generation.
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Before detection of thin surfaces
After detection, all surfaces are correctly reattached.
Meshing without thin surfaces elimination
Meshing with thin surface elimination: real improvement of the meshing quality
Advantages to eliminate the thin surfaces
-
detect and eliminate overlaps between faces according to the maximum distance parameter value. This parameter gives the maximum distance, between 2 faces which present an overlap, computed on the normal axis (see the Figure 3). When an overlap is detected, DeltaMESH will redefined automatically the boundaries of the faces in order to create a perfect geometrical connection (see the Figure 3).
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Illustration of the “maximal gap” parameter definition
Illustration of a geometrical overlap before detection by DeltaMESH
Illustration of the geometrical correction made by DeltaMESH
Figure 3: Automatic treatment of a geometrical overlap
-
detect and fill the geometrical holes according to the “maximum size” parameter value. DeltaMESH will detect automatically the geometrical holes and create a new surface to fill the hole (see the Figure 4). Be careful, this first version of the hole filling function gives a good result only with “planned holes”.
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This illustration presents a geometrical hole due to a bad definition of a face.
With the new functionality of DeltaMESH, this hole will be automatically detected and filled. In this case, the boundary is redefined without creating a new surface.
Figure 4: Automatic geometrical holes filling
After the joining session, you can display the eliminated thin surfaces and the eliminated duplicated surfaces by selecting Show Thin surfaces and Show Duplicated surfaces in the 3D View contextual menu. It is also possible to join only a sub-set of surfaces and/or curves, e.g. when the punch and die are different shaped tools. These selected entities will be either a group created automatically when the CAD files are imported, or an object created beforehand by the user using Selection tools. Notes:
·
The Joining tolerance is only used during the first step of the joining session. Its value must not be too great. Its default value is equal to the reading tolerance value.
·
The value of the Minimal Feature Size parameter is expressed in the length unit used for the model. It must be greater than the import tolerance value used for the CAD file import phase.
·
For a CAD model without big defects, a value of 0.5 mm for the Minimal Feature size is generally sufficient. However, it is not recommended to apply a value too large to this parameter. The maximum value will be between 0.8 and 1.0 mm.
·
When you use a large value for the Minimal Feature Size, it is not recommended to activate the elimination of the thin surfaces because it erases too many geometrical details.
Complete an existing topological model
In certain cases, we must complete an existing topological model (see subsection “Execution of Joining and Checking”) by processing a new joining session. In this case, we can launch a new joining process with new joining parameters (e.g. Minimal Feature size = 0.8 mm; Automatic deletion of thin surfaces = Off; Automatic deletion of duplicated surfaces = On)
You will have the choice to complete the existing topological model or to create a new topological model with these new joining parameters.
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If you choose the Complete mode, the following dialog will appear:
This dialog is displayed before proceeding to a new joining session in order to check the parameter values. The joining tolerance parameter is grayed because as we said, in the complete mode, this parameter has no influence. Just click OK to complete the topological model.
Meshing Presentation In this phase the discretization criteria (mesh density) are defined and the mesh of the topological model (created in the joining phase) is generated. The discretization criteria can be defined using: -
the minimum and maximum sizes of the elements,
-
the maximum distance between the elements and the geometry (chordal error),
-
the maximum angle between two adjacent elements (angle criterion),
-
the type of meshing algorithm.
Continuity of the mesh between each surface is ensured automatically on the surface edges where joining has been performed beforehand.
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Definition of Meshing Parameters The meshing parameters are defined by clicking the Meshing tab on the Meshing dialog.
Meshing consists in defining the discretization criteria on the geometric entities (surfaces and/or curves) and then automatically meshing these entities. The different discretization criteria are: -
the type of meshing algorithm (parametric, uniform, progressive),
-
the minimum and maximum sizes of elements,
-
the chordal error,
-
the angle criterion
The mesh density is computed locally on the geometric entities in conformity with these different discretization criteria. Their respective effects can be combined on a single geometric entity. The mesh obtained complies with the parameter requiring the highest density, but without generating elements smaller than the minimum size or larger than the maximum size (with a certain margin of error). In any given module, the continuity of the mesh between two adjacent surfaces is automatically ensured by repeating discretization of the edges of topologically adjacent surfaces if they have already been meshed.
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Assign all criteria before meshing option DeltaMESH can mesh a set of objects containing groups of surfaces using two different methods, determined by the status of the Assign all criteria before meshing check box in the Meshing tab. - Assign all criteria before meshing check box is deactivated (recommended). DeltaMESH computes the discretization criteria for each object and meshes it immediately in the order defined in the Objects to mesh list. In this case, the discretization used to mesh the surfaces of the first objects meshed is imposed on the edges of the adjacent surfaces of the subsequently meshed objects. This method makes it possible to prioritize the meshing of certain areas (fillets, blank holder surface, etc.). - Assign all criteria before meshing check box is activated. DeltaMESH computes the discretization criteria for all the objects, and then meshes them. In this case, the highest discretization level is imposed on edges common to two adjacent surfaces belonging to two different objects, before meshing is performed. Note:
·
We recommend you to leave the Assign all criteria before meshing check box deactivated, and prioritize meshing of important areas for simulation (in particular the die entry fillet).
Type of meshing algorithm DeltaMESH comprises several meshing algorithms that ensure the geometric constraints of different areas automatically satisfied for the stamping simulation. The following mesh generators are accessible in the Algorithm panel: - Parametric: A regular mesh generator in the parametric space, which puts the priority on compliance with the natural lines of CAD surfaces. - Uniform: A free mesh generator in the 3D space that puts the priority on the shape quality of the elements without constraints in relation to the parametric definition of the surfaces. The size of the elements is uniform within each surface. - Progressive: A free mesh generator in the 3D space that puts the priority on the shape quality of the elements without constraints in relation to the parametric definition of the surfaces. The size of the elements varies according to the Progression ratio, which defines the size ratio between two adjacent elements. The table below defines the advantages and disadvantages of each mesh generator.
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Type of algorithm
Advantages
Disadvantages
Advice
PARAMETRIC
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Follows and preserves the geometry
-
-
-
Possible to elongate elements in one direction
-
Regular shape of elements Insensitive to geometric defects
UNIFORM
-
PROGRESSIVE
-
Variable element size Regular shape of elements
Sensitive to geometric defects
The geometric lines of surfaces are not necessarily preserved. Constant size of elements on a surface
To be used mainly for meshing tools.
To be used when the PARAMETRIC mesh generator cannot generate a correct mesh on a surface.
-
Increase the minimum element size to avoid generating too many elements on large surface.
-
Sensitive to small geometric edges propagating their size.
-
The geometric lines of surfaces are not necessarily preserved.
To be used with caution when small geometric edges are present.
-
Increase the minimum element size.
Notes:
·
If a surface and/or a curve cannot be meshed, it is possible to only generate this entity's nodes by activating the Nodes only toggle (see subsection “Solutions to Complete a Mesh”).
·
The free nodes will be loaded in the Others object in the Visibility tab. They can be recovered in the preprocessor module and will be used to interactively construct the missing elements.
Quadrangular surface detection function The Quad surface detection toggle is used to activate a DeltaMESH function that automatically detects surfaces with 3 or 4 sides. Once detected, these surfaces automatically have priority for meshing. The generated mesh will follow lines parallel to the surface sides, instead of lines parallel to the CAD surfaces' iso-parametric lines. 3 or 4-sided surfaces are detected using the following two configuration parameters (see subsection “Quad. Surface detection panel”): -
Corner limit angle:
Angle to detect the surface corners (10° by default).
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Notes:
·
This angle’s value must not be too small because too many corners would be detected (and not enough 3 or 4-sided surfaces).
·
Neither must it be too large because false 3 or 4-sided surfaces would be detected. c> corner limit angle
X
c< corner limit angle
X
c> corner limit angle c> corner limit angle
X
X c> corner limit angle
X : corners selected to describe the 4-sided surface ( c> corner limit angle 10°)
: corner not selected to describe the 4-sided surface ( < corner limit angle 10°) c
-
Quad distortion angle:
Maximum distortion angle (default 40°) of elements in relation to a perfect quadrangle.
Note:
·
As this value is reduced, the number of selected 3 or 4-sided surfaces will decrease.
Before meshing 3 or 4-sided surfaces, DeltaMESH will automatically propagate the element densities computed on the different edges of these surfaces, to generate the maximum number of quadrangular elements. This propagation from one surface to another is controlled by the Density variation parameter defining the maximum permitted progression in element size. The density variation coefficient must be greater than 1.0. The higher the value, the lesser the density propagated and the transitions between surfaces will be performed by triangular elements. The coefficient may exceptionally be set to 1.0 if you wish to maximize density propagation and obtain as many quadrangular elements as possible (this will greatly increase the number of elements). The progression in mesh density is also controlled by the Over discretization configuration parameter (see subsection “Quad. Surface detection panel”), which defines the type of density progression within each surface. When it is activated, more elements are obtained within each surface (about 10%).
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Size criteria The size criteria are defined in the Size panel. The Maximum size parameter defines the maximum element size during meshing. If the other criteria do not require a smaller size, the elements will take this maximum size. The Minimum size parameter defines the minimum element size. This value will be maintained as a priority to the other criteria that may create smaller elements. The element size is computed as the distance between two nodes belonging to the same edge. This size should not be confused with the size used by the solver to compute the time step of the explicit computation (characteristic length). The maximum size determines the elongation and warping of the generated elements. If you want to improve these criteria, simply reduce the maximum size value (more elements will be generated). The size criteria must be expressed in the model's length unit. They must be positive and greater than the precision value defined in the Reference space configuration parameter (see subsection “Model panel”). Note:
·
The minimum size must not be too large, otherwise discretization of small surfaces, especially surfaces representing fillets, may not be regular.
Chordal error The chordal criterion is defined in the Chordal error panel by clicking on the Active check box. It defines the maximum distance between a point located in an element's plane and the model's geometry that must be preserved when meshing.
Maximum distance from the mesh to the geometry
The chordal criterion value must be entered in the model's length unit. It must be positive and greater than the precision value defined in the Reference space configuration parameter (see subsection “Model panel”). By activating the Follow isoparametrics toggle it is possible to compute the chordal error along the surface's iso-parametric curves, instead of on the surface itself. This generates meshes whose discretization is uniform between the boundaries and the surface interior. Note: It may be useful to activate the Follow isoparametrics check box if you want to obtain more elements and orient the mesh following iso-parametric lines in the plane tangent to the surface.
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Angle criterion The angle criterion is defined by clicking the Active check box in the Angle Criterion panel. The maximum angle parameter defines the maximum angle between 2 adjacent elements for meshing within the same surface and/or the same 3D curve. The angle criteria value must be defined in degrees, and be greater than 0°.
Max angle betw. normals of the 2 elements.
By activating the Follow iso-parametrics check box, it is possible to compute the angle criterion along the surface's iso-parametric curves, instead of on the surface itself. This produces meshes where discretization is uniform between the boundaries and surface interior. Notes:
·
It may be useful to activate this toggle if you want to obtain a more regular mesh or if the surfaces have two important curvatures in two different directions. It is recommend to keep deactivate this if a small angle value is used (less than 10°).
Angle error on a surface in space
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Angle error with Follow iso-parametrics option on a planar surface.
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MESH CHECK AND REPAIR Import Check We recommend you to examine the output report displayed in the DeltaMESH console. In particular, this report gives the number of surfaces and/or 3D curves: -
present in the CAD file,
-
created by DeltaMESH,
-
that are independent (not referenced by another entity),
-
eliminated because they are smaller than the import tolerance.
The output file recalls the import parameter used for each CAD files, gives the number of imported surfaces and presents some advices in the case of a problematic import status, as shown below in the output file example after the IGES file importing. IMPORT SESSION _______________________________________________________________________________ Import parameters: ______________________________________________________________________________ | | | | | | | | | Faces | Curves | Prefer 3D | | CAD model | Import tol | import | import | contours | |_______________________________|____________|__________|__________|___________| | | | | | | | deltacup_fillet.igs | 0.1 | YES | NO | NO | | deltacup_die.igs | 0.1 | YES | NO | NO | | deltacup_bh.igs | 0.1 | YES | NO | NO | |_______________________________|____________|__________|__________|___________| Import results: - 49 faces were imported in DeltaMESH Import status: OK. WARNING: We have detected in the definition of some files, some inconsistencies between 2D and 3D faces boundaries representation. After joining session, if it remains some amazing geometrical free edges, re-import the CAD model after changing "Prefer 3D contours" parameter. The related files are: - "deltacup_die.igs" - "deltacup_bh.igs" Cpu time (user+system) for the whole DeltaMESH session: 0.66 seconds
You can also access a more detailed report by clicking the button. The CAD history report gives some more precise information, as shown below in an extract of the CAD history file after the IGES file importing.
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----------------------------------Summary of reading IGES file ----------------------------------Type Entity 116 Point 144 Trimmed Parametric Surface 128 Rational B-Spline Surface 114 Parametric Spline Surface 118 Ruled Surface 120 Surface of Revolution 122 Tabulated Cylinder 140 Offset Surface 108 Plane 402 Associativity Instance(group) 1 predefined group(s) 25 patch(es) replaced by bounded faces Faces group number 2 created ----------------------------------Type Created Entities ----------------------------------Faces Group 1 Face 40 Edge 155 Vertex 216 -----------------------------------
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File 0 15 40 0 0 0 0 0 0 1
Created 0 15 40 0 0 0 0 0 0 1
Indepen. 0 15 25 0 0 0 0 0 0 1
< Toler. 0 0 0 0 0 0 0 0 0 0
Part 1
Part 2
It is very important to check the Part 1 called Summary of reading CAD file. This part is divided into six columns. -
The first column called Type indicates the name of the entities
-
The second column called Entity gives the description of the entity
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The third column called File indicates the number of entities present in the CAD file.
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The fourth column Created gives the number of entities created by DeltaMESH
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The fifth column Indepen. indicates the number of independent entities created by DeltaMESH
-
The sixth column < Toler. gives the number of entities that have been eliminated because they are smaller than CAD File reading tolerance
For example, in deltacup_die.igs file, there are 40 “128 type” entities (Rational B-Spline Surface) present in the CAD file. 40 entities have been created by DeltaMESH and among these ones, 25 are independent i.e. they are not referenced by another entities (except 402 form7 groups). The 15 remaining ones are used as the original untrimmed surfaces to obtain the 15 “144 type” entities. Moreover, for each entity, we must check that: number in 3rd column = (number in 4th column + number in 6th column) This rule is true for all entities except for the 108 type entities (“plan”). The Part 2 summarizes the total number of faces groups, faces, edges and vertices created. We can also read the session time.
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If messages indicate that it was not possible to translate certain CAD entities, you must check the CAD export options chosen in the CAD software (see the advice in subsections Interpreted CAD Entities and Interface Options for Different CAD Systems). If import problems arise, the user can re-import this CAD file in the original CAD software from which it has been generated (preferably, in an empty project). This permits to identify any problems that could have appeared during CAD file generation, to solve them in the CAD system and to generate a new CAD file.
Joining check After joining the mesh, the user should do several checks, as described more in details below: -
Display the eliminated surfaces
-
Check the surfaces free edges
-
Look at the output report
Eliminated surfaces After the joining session, you can display the eliminated thin surfaces and the eliminated duplicated surfaces by selecting Show / Thin surfaces and Show / Duplicated surfaces in the 3D View contextual menu.
Surfaces free edges
After joining, the model's free edges can be viewed by selecting Show / Surface free edges in the 3D View contextual menu. If internal free/multiple edges remain after the first joining operation, additional joining operations (iterative joining) can be performed to reduce their number. This is very fast because iterative joining is only performed on the free/multiple edges left in the model. (see RepairFAQ paragraph below)
Output report We recommend you to examine the detailed report in the DeltaMESH console. This report on the surfaces specifies: -
the total number of “geometric free/multiple edges”,
-
the number of “closed contours” formed by free/multiple edges,
-
the number of “open lists” formed by free/multiple edges.
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If only one “closed contour” is listed, this means all the joined surfaces are connected, and that this closed contour represents the external boundary of the tool. Internal “closed contours” make it possible to visually detect duplicated surfaces, substantially superimposed surfaces, isolated surfaces, and gaps in the model (surfaces missing).
Final Mesh check After meshing, the user should do several checks, as described more in details below: -
check surfaces meshes when warnings have been written
-
Check the free and multiple edges
-
Check if undercut appears
-
Display the mesh quality contours
-
Look at the output report
If problems appear it is important to check also the import and the joining to understand the origin of the problem and repair it easily.
Surfaces mesh with warning It is recommended to check surface meshes when DeltaMESH indicates an information message (WARxxx) in the report. To locate the incriminated surface, simply choose the Surface entity type in the Entity information dialog and enter the identifier indicated in the information message. Then, the concerned surface is highlighted.
Free and multiple edges
It is useful to display the free and multiple edges of the mesh using the show toolbar. We advise you to avoid free or multiple edges inside the mesh, since their presence could not only impede the execution of an offset during the generation of tools, but also affect the results accuracy if the holes or overlaps reach 10% of the blank thickness.
Undercut Make sure that there are no undercuts in the mesh. Even if the initial CAD has no undercut, the mesh can induce undercut in non-planar vertical parts. For example in the curved vertical surface, if the discretizations on the top and bottom lines of the surface do not coincide, there will unavoidably be some undercut elements.
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Top view:
A Cross section AA:
Edges on bottom line
CAD CAD
A Mesh
Edges on the top line
The maximum value of the undercut introduced during the meshing process is equal to the Chordal error. The undercut area can be found using Analysis contour /Undercut. It displays the angle or the critical areas (shown in red in the figure below) . Threshold = 90°+ critical angle Undercut : 90° Critical : Threshold Safe : > Threshold
Stamping direction
n
Element surface
Mesh quality contours Other quality problems may appear because of a bad initial CAD data (overlapping of surfaces, non trimmed surfaces) or a bad meshing. The following Mesh Quality contours can be used to find the elements which are warped, very thin or distorted. -
Angle between shells:
the value is the angle between the average normals of these two elements. If it exceeds 20° for the fillets (10° if a springback calculation is planned), and 30° for the rest, that means that there can be a mesh problem like overlapping or distorted element.
-
warping:
-
Area:
-
Minimum inner angle:
big warping can indicate a problem of mesh quality.
if the area of the elements is very small (0.01 mm), problems might appear during offset. if there is a very small angle in an element, problems could
occur during offset. See the remeshing action chapter to correct easily this type of problem
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Iso parametric curves It is possible to display surfaces with several iso-parametric curves in each U and V direction (see subsection Visualization panel). This permits to understand in some cases why the mesh is not good (generally due to a bad parameterization of the surface).
Output report We recommend you examine the output report in the DeltaMESH console. Following is an example output file after the meshing session.
_______________________________________________________________________________ MESHING SESSION _______________________________________________________________________________ Meshing parameters: Setting mesh type on a selection - Mesh type : PARAMETRIC - Quadrangulars detection : YES Setting the size criterion on a selection - Maximum size : 30.000000 - Minimum size : 0.100000 Setting the chordal error criterion on a selection - Limit chordal error : 0.150000 - Follow isoparametric curves : YES Setting the angle criterion on a selection - Limit angle : 15.000000 - Follow isoparametric curves : YES Meshing of all surfaces, (force mesh generation activated) Meshing Status: OK. All of the 49 faces processed were meshed. The resulted mesh is composed with 4002 elements and 3825 nodes. Cpu time (user+system) for the whole DeltaMESH session: 1.81 seconds
The information indicated in the output file is very important. The meshing strategy is recalled in it. In this example, the default values are used. This report indicates: -
the total number of meshed surfaces,
-
the number of nodes and elements generated,
-
if applicable, the error or information messages displayed during meshing.
In the above report, 49 surfaces are present in the topological model and all have been meshed. The meshing Status is OK. This mesh is constituted with 3825 nodes and 4002 elements.
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Mesh Repair and FAQ If import problem -
The geometry does not look like the CAD geometry, there are many cylinders and cones.
The IGES files are not exported from CAD software with the right option. Verify, you have well choose 142/144 entities. See CAD model exchange from CAD systems to DeltaMESH chapter for more details. -
Some holes / free edges appear between surfaces.
It may come from inconsistent between 2D and 3D representation in the CAD file. Try to use Prefer 3D boundaries or IGES preferred representation option during import.
If joining problem, if complex part If internal free/multiple edges remain after the first joining operation, additional joining operations (iterative joining) can be performed to reduce their number. This is very fast because iterative joining is only performed on the free/multiple edges left in the model. The procedure to join together a complex model is as follows: -
Perform an initial joining with the Apply to all objects toggle activated, using for example the following setting parameters: ·
Joining tolerance = 0.1 mm
·
Minimum Feature size = 0.5 mm
·
Automatic deletion of thin surfaces = On
·
Automatic deletion of duplicated surfaces = On
·
Automatic deletion of geometrical overlaps = On
·
Automatic holes filling = Off
-
After the previous joining session, verify the model's free/multiple edges by displaying them and by examining the detailed report. If there is only one contour (the part's external edge), this means that the joining operation is complete. You can stop the procedure.
-
Eliminate the unnecessary surfaces detected by the first joining (unwanted surfaces, superimposed surfaces, construction plane, etc.) before starting complementary joining. Simply create an object containing all the “correct surfaces” by removing the unnecessary surfaces. Then, this object will be used for subsequent iterative joining operations.
-
Deactivate the Apply to all objects check box and perform a new joining session on the previous created object, still using the same tolerance values. After clicking the
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button, a warning message is displayed. You can either delete the existing topological entities or complete them. You have to choose the Delete option in order to re-create a new topological model from a “clean” object. join
-
Check for free/multiple edges, and if there are any, complete the topological model with a new joining session by increasing the tolerance value: ·
Minimum feature size = 0.8 mm
·
Automatic deletion of thin surfaces = Off
·
Automatic deletion of duplicated surfaces = On
·
Automatic deletion of geometrical overlaps = Off
·
Automatic holes filling = Off
Notes:
·
If you increase the minimum feature size value too much, there is a risk of damaging the geometry and generating a much distorted mesh near to the defect where joining have been “forced”. In this case it is preferable to keep a few internal free edges and stitch the element nodes after meshing.
·
When you complete a topological model, it is recommended to deactivate the elimination of thin surfaces because some important geometrical detail can be erased using this function.
If meshing problem If a problem appears during the mesh quality control, it must be repaired if accurate contact is planned to be used (see Simulation methodology for high quality stamping section). -
Some surfaces are not trimmed or overlap others
Remove the problem surfaces from the object,(simply create an object containing all the good surfaces by removing one of the not trimmed or overlapped surface) and do again a joining and a meshing deactivating the Apply to all objects option. -
Small surfaces overlaps others
Do again a joining and a meshing with a bigger value of maximum gap for Automatic deletion of geometrical overlaps. Or if the problem concern only very few elements, delete them and use geometry/edition tools from nodes or elements, to eliminate the problematic element. For instance, you can use the merge node to node option. -
Elements are too warped, too thin or too distorted.
Make an automatic remeshing (see the remeshing action chapter for more details)
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Some fillets disappear or are degenerated
Reduce the Maximal width parameter of Automatic deletion of thin surfaces or disable the function during the joining.
Advanced repair General rules To mesh non-deformable tools, it is preferable to use the Parametric mesh generator because it produces a mesh that follows more closely the surfacic model of the tools. Most of the elements that DeltaMESH creates are quadrangular and follow the iso-parametric lines of the CAD geometry. This minimizes warping of the elements, and the corresponding criteria are broadly satisfied provided the surfaces do not exhibit themselves excessive warping (in which case a higher discretization level will minimize the problem). Elements can, if necessary, be highly elongated in one direction compared to the other, to follow the geometry as closely as possible and simultaneously minimize the total number of elements (in this case the elements are not very satisfactory with regard to the standard shape criteria adopted in Finite Elements). This is not important for tool meshing, and does not penalize the simulation results. However, if preferred, it is possible to reduce the maximum size value, and reduce elongation of the elements. The chordal error and angle criteria are complementary: -
The chordal criterion ensures that the surface geometry is preserved when it comprises large curvature radii.
-
The angle criterion sets a minimum discretization for small radii.
Note:
·
The numeric parameter values given in the paragraphs below have been defined for automobile bodywork parts with sizes in the order of 1,000 to 2,000 mm. They must be modified if the parts are of a different size or use a different unit of measurement.
Special areas: die entry fillet, die bottom fillet, etc. It is recommended to give priority to meshing these areas. DeltaMESH will give priority to meshing these crucial areas (by specifying the priorities and meshing these areas first). They will not be disrupted by the other areas, thereby ensuring optimum quality. The meshes in areas with a lower priority are then connected automatically to ensure continuity (the layers of transition elements are then located in these areas, instead of in the sensitive areas).
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To give priority to meshing these areas: -
Deactivate the Apply to all objects check box in the Meshing dialog.
-
First select the object containing the surfaces of these areas and define the meshing criteria (Meshing parameters dialog). Add the object to the list of Objects to mesh.
-
Then select the objects containing the others groups of surfaces, and define their meshing criteria.
-
Do not activate the Assign all criteria before meshing check box.
The following meshing parameters are recommended for these areas: -
Algorithm: Parametric The Quad. surface detection option
can be used to good effect in these areas to generate the maximum number of quadrangular elements with a mesh as smooth as possible. -
Maximum size:
30 mm
-
Minimum size:
0.1 mm (do not assign a too large value to Minimum size, it
might reduce the regularity of the mesh). -
Chordal error:
-
Angle error:
0.15 mm (identical to the value used for the other areas).
10° to 15°. It is possible to use a lower value when you want to show the curvatures very precisely (e.g. for a springback computation). In this case we recommend you deactivate the Follow iso-parametrics check box.
Die internal area ("die bottom")and Blank holder surface This is the part of the die located under the punch, whose mesh will be offset to automatically create the mesh of the punch. The recommended meshing parameters for this area are the same as those used for priority areas. However, if you want to obtain less elements, you can: -
Deactivate the toggle Follow iso-parametrics
-
Increase the Density variation parameter
-
Increase the Maximum Angle parameter (15°)
-
Increase the Maximum size parameter (40 to 50 mm)
The blank holder is considered to be non-deformable. In this case the recommended meshing parameters are the same as those used for the internal part of the die.
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Meshing the blank The following meshing algorithms can be chosen to maximize the number of quadrangular elements on the blank: -
Parametric
when the iso-parametrics are regular and the blank sides are parallel to these iso-parametrics,
-
Uniform
in other cases.
The Quad. surface detection option can be used to good effect when the overall blank shape is rectangular or tubular (e.g. for hydroforming). A density progression coefficient of 1.2 (exceptionally 1.0) will enable you to generate a mesh comprising mostly quadrangular elements. We recommend you only use size criteria and deactivate the angle and chordal criteria if you want to achieve constant element size. If necessary it may be useful to use the Barycentric smoothing function to increase the "finite element quality" of the mesh (see subsection “Barycentric Smoothing Action”).
Solutions to Complete a Mesh When the model is not meshed completely, DeltaMESH gives the list of identifiers of non-meshed surfaces and/or curves in the DeltaMESH console. The two main factors preventing a surface being meshed are: -
discretization criteria incompatible with the size or geometry of this surface (warping in particular),
-
CAD geometry comprising very substantial defects (surface edges comprising a reversal point, very high surface curvature value, highly distorted iso-parametrics, very irregular distribution of iso-parametrics, etc.).
In the text below, various strategies are presented for completing an initial mesh. They should be used in the described order. To use these strategies, the mesh failed surfaces must be grouped in an object.
Strategy 1 This strategy ensures mesh continuity. Continue meshing of these surfaces within the same module in Complete mode: 1. Reduce the Maximum size criteria. 2. If (1) fails, deactivate the Angle and Chordal error criteria. 3. If (2) fails, use a Uniform mesh type (and increase the min. size slightly to avoid the risk of generating a large number of small elements on the large surfaces).
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Strategy 2 This strategy ensures mesh continuity. Start the meshing phase again with the problematic surfaces. In this way they will not be affected by the meshing of adjacent surfaces. 1. Use the same criteria on these surfaces as in the initial mesh. 2. If (1) fails, reduce the Maximum size criteria on these surfaces. 3. If (2) fails, use a Uniform mesh type (and slightly increase the min. size). If the strategy 2 succeeds, you can then restart meshing in Complete mode with the initial criteria (since the "problematic" surfaces have now been meshed, DeltaMESH will not mesh them again).
Strategy 3 This strategy does not preserve mesh continuity. Compared with strategy 2 it avoids having to re-mesh the whole model, but requires interactive connecting of the mesh. Therefore it must only be used if the number of surfaces to re-mesh is low and they are small. Copy the joined model into a new module, and only mesh the problematic surfaces. 1. Use the same criteria as in the initial mesh of the failed surfaces. 2. If (1) fails, reduce the Maximum size criteria for these surfaces. 3. If (2) fails, use a Uniform mesh type (and increase the minimum size slightly). If the strategy 3 succeeds, the two meshes, both contained in a module, must be interactively connected (with Edition -> Elements option in Geometry menu).
Strategy 4 This strategy does not generate a mesh. It only generates nodes on the non-meshed surfaces. In the module containing the initial mesh: 1. Keep the existing criteria and mesh with the Nodes only option activated. 2. If (1) fails, reduce the Maximum size criteria before meshing. 3. If (2) fails, use a Uniform mesh type before meshing. If the strategy 4 succeeds, the generated free nodes are located in the Others object. They can then be recovered in the preprocessor module to interactively generate the missing elements using these nodes.
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THE REMESHING ACTION Presentation Remeshing is the fourth step of the DeltaMESH actions. It is an optional step. This complementary action allows the user to improve the mesh quality whenever necessary. Its process is very simple and useful. The remeshing operation will detect automatically faces with a bad quality mesh due to the presence of some erroneous surfaces in the CAD model. The faces detection is done by applying three different element quality criteria. DeltaMESH will select these bad mesh quality faces and also their adjacent ones. Their meshes will be deleted. Then, a new meshing strategy specific to the erroneous surfaces can be applied. This post meshing function reduces the time spent by the user to correct the mesh when the CAD model contains some erroneous surfaces. Then, we can obtain directly and more quickly a better mesh. The following figures illustrate the interest of the remeshing (in this example, we have specified Angle between elements to 30°:
Before the remeshing, the maximal angle between elements was about 41°
After the automatic remeshing, the maximal angle between elements is equal to 24.4°
After the remeshing session, you can display the eventual remeshed surfaces by selecting Show -> Remeshed surfaces in the 3D View contextual menu.
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Detection parameters The detection of the invalid meshes depends on three different parameters values: -
Angle between elements: 30
-
Warping:
15
-
Area:
0.001 (deactivated by default).
(activated by default); (deactivated by default),
The Angle between elements threshold permits to detect the surfaces in which the angle between element normals is greater than this threshold value (30° by default). However, the faces situated along geometrical sharp edges will not be detected. The Warping threshold permits to detect the surfaces in which the element warping is greater than this value. The Area threshold permits to detect the surfaces in which the element area is lower than this value. After the detection operation, DeltaMESH will delete the different selected meshes (the invalid and their adjacent)
Remeshing parameters The remeshing parameters definitions are given in the previous chapter (Meshing the Topological model). A toggle allows whether or not to apply two different meshing strategies for the invalid meshes surfaces and their adjacent faces (see Figure 2 and Figure 3).
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Figure 2: Remeshing parameters dialog box
Figure 3: Interest of defining two different remeshing strategies
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Figure 3 illustrates the capability of defining two different meshing strategies for the selected faces and their adjacency. For the main selected faces (darker shade), we applied a 3D meshing algorithm (progressive). For their neighbours (lighter shade), we used the default meshing strategy. A very localized modification is possible by applying this strategy. The default parameter values are as follow: Faces detection criteria Angle between elements
ON
value
30.0
Warping
OFF
value
15.0
Area
OFF
value
0.001
Same parameters for both faces
OFF
Meshing criteria Selected faces
Adjacent faces
Algorithm
Progressive
Parametric
Progressive ratio
1.2
1.2
Quad. Surface detection
OFF
ON
Density variation
1.2
1.2
Minimum element size
0.1
0.1
Maximum element size
10.0
30.0
Active
ON
ON
Follow isoparmaetrics
ON
ON
Maximum distance
0.15
0.15
Active
ON
ON
Follow isoparmaetrics
ON
ON
Maximum distance
15.0
15.0
Algorithm
Size
Chrodal error
Angle crietria
By default, this fourth step is deactivated. The remeshing parameters are defined by clicking the Remeshing tab on the Remeshing dialog.
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It is possible (but not recommended) to mesh all the model's geometric entities (surfaces and/or curves) in a single operation, by activating the Apply to all objects check box. In this case it is sufficient to click the zone containing the parameters to display the Meshing parameters dialog, and modify the default meshing parameters. Once modified, these parameters will be applied to the whole model.
Execution and Checking The remeshing can be executed by clicking the Mesh button in the remeshing dialog. We recommend that you examine the output report in the DeltaMESH console. Following is an example output file after the meshing session. _______________________________________________________________________________ MESHING SESSION _______________________________________________________________________________ Meshing parameters: Setting mesh type on - Mesh type : PROGRESSIVE - Quadrangulars detection : NO Setting the size criterion on - Maximum size : 5.000000 - Minimum size : 0.100000 Setting the chordal error criterion on - Limit chordal error : 0.150000 - Follow isoparametric curves : YES Setting the angle criterion on - Limit angle : 10.000000 - Follow isoparametric curves : NO Meshing of , (force mesh generation activated) Setting mesh type on - Mesh type : PARAMETRIC - Quadrangulars detection : NO Setting the size criterion on - Maximum size : 5.000000 - Minimum size : 0.100000 Setting the chordal error criterion on - Limit chordal error : 0.150000 - Follow isoparametric curves : YES Setting the angle criterion on - Limit angle : 15.000000 - Follow isoparametric curves : YES Meshing of , (force mesh generation activated)
Remeshing strategy for the main selected faces
Remeshing strategy for the adajacent faces
Meshing Status: NO OK. All of the 28 faces processed were meshed but the following messages were generated: - The mesh of some faces is incoherent. The faces are: 3088, The resulted mesh is composed with 13998 elements and 12012 nodes. Cpu time (user+system) for the whole DeltaMESH session: 15.00 seconds
The information indicated in the output file is very important. The meshing strategy is recalled in it. In this example, the default values are used.
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This report indicates: -
the total number of meshed surfaces,
-
the number of nodes and elements generated,
-
if applicable, the error or warning messages displayed during meshing.
In the above report, 28 surfaces have been selected and all have been meshed. The meshing Status is NOT OK because one of these faces presents an incoherent mesh. The identifier of this face is given in order to check it in the GUI. This mesh is constituted with 12012 nodes and 13998 elements. It is recommended to check surface meshes when DeltaMESH indicates a warning message (WARxxx) in the report. To locate the incriminated surface, simply choose the Surface entity type in the Entity information dialog (appearing by choosing Information on… Entities option of the Analysis menu) and enter the identifier indicated in the warning message. Then, the concerned surface is highlighted. It is useful to display the free and multiple edges of the mesh by selecting the Show Free edges and Show Multiple edges in the 3D View contextual menu. The Contour tab in the Analysis toolbar gives access to the Mesh Quality menu enabling you to display the element quality criteria. It is possible to display surfaces with several iso-parametric curves in each U and V direction (see subsection “Visualization panel”). This permits to understand in some cases why the mesh is not good (generally due to a bad parameterization of the surface).
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THE MULTIPATCHING ACTION Presentation Multipatching is the new DeltaMESH tool that allows the user to improve the mesh quality by modifying topologicaly the model automaticaly or manualy. Its process is very simple and useful. This action is made available by clicking the Multi-patch dialog will then pop up.
button. The Multipatch
The multipatching operation will detect automatically surfaces containing faces near borders with a bad quality, due to the presence of some erroneous surfaces in the CAD model. The faces detection is done by applying different element quality criteria. DeltaMESH will select these bad mesh quality faces and also their adjacent ones to make connex surface groups. Each group is transformed into a multipatch and considered as one surface. Treatments are done to mesh each multipatch without taking internal borders into account. This post meshing function can also be done with user’s defined groups It is useful to correct thin surfaces’ packet, over cutting model, bad surface parameterization, points … The following figures illustrate the interest of the multipatching:
Before the multipatching, the mesh contain small and flat elements to respect CAD surface borders.
After the automatic multipatching, an outline disappears. Elements are regular
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Detection parameters The detection of the invalid meshes depends on six different parameters values: -
Angle between elements: 30
-
Warping:
15
-
Area:
0.001 (deactivated by default).
-
Size:
0.1 (activated by default).
-
Angle min.:
1. (deactivated by default).
-
Angle max.:
175. (deactivated by default).
(activated by default); (deactivated by default),
The Angle between elements threshold permits to detect the surfaces in which the angle between element normals is greater than this threshold value (30° by default). However, the faces situated along geometrical sharp edges will not be detected. The Warping threshold permits to detect the surfaces in which the element warping is greater than this value. The Area threshold permits to detect the surfaces in which the element area is lower than this value. The Size threshold permits to detect the surfaces in which the smallest element dimension is lower than this value. The Angle min. threshold permits to detect the surfaces in which the smallest angle’s element is lower than this value. The Angle max. threshold permits to detect the surfaces in which the bigest angle’s element is upper than this value. After the detection operation, DeltaMESH will creat the different multipatch and mesh them
Multipatching parameter The elimination parameter give the tolerance to remove nodes too close one another. This coefficient, multiplied by minimum size mesh criteria represent the length under which two nodes are merged. Notes:
·
A value between 1 and 3 is correct and it is not recommended to exceed 5
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Figure 2: Automatic repatching parameters dialog box
Manual multipatching Multipatching is also available after meshing from a user’s surface’s selection: a multipatch is made for each object selected. Two methodes are available: -
surface is created by the interpolation of ‘children’ surfaces. This method give good results with a great amount of thin surfaces or bad parametrised surface(s). NURBS: A
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Before the multipatching, the model contain many thin surfaces than impose many small elements.
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New surfaces replace packet of thin surfaces The mesh is less discretized and have a better quality.
The group of face received treatment to eliminate small element present near surface border. The group is consider like a new surface. Elements can cross internal border. Zone:
Notes:
·
Zone is the option used by the automatic multipatching.
·
For complex cases in which NURBS can’t generate a multipatch, zone method is automatically chosen.
·
All surfaces selected for a multipatch must be neighbor.
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Figure 4: Manual repatching parameters dialog box
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OTHER DELTAMESH ACTIONS The different functions of DeltaMESH described in this paragraph help the user to correct and improve interactively the meshing quality. The tools include: -
Mesh delete tool
-
Barycentric smoothing tool
-
Eliminated surface restoring tool
-
Part splitting
Mesh Deletion The deletion action is made available by clicking the button of the CAD tab from Data Set-up toolbar or by selecting DeltaMESH -> Mesh deletion… from the Geometry menu. This action gives access to the Delete mesh dialog.
This function is used to delete the mesh (elements, nodes, discretization criteria) belonging to geometric entities (surfaces and/or curves), imported and meshed by DeltaMESH. This will enable you to subsequently remesh these different entities using other strategies (sizes, algorithm types, etc.) and obtain a new mesh. This deletion action can be applied: -
To a selection of surfaces and/or curves. You just have to select the surfaces and/or curves that you want to delete the mesh.
-
To one or several groups. You just have to choose which group mesh will be deleted by this action
-
To all the geometric entities (function previously available when starting meshing). In this case, all the elements and nodes will be deleted (very quickly) and the next mesh will be created using the topological model.
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The selected objects must contain geometric entities (surfaces and/or curves) and not mesh entities (nodes and elements). DeltaMESH carries out the mesh deletion action on geometric entities. If the mesh is partially deleted, the nodes belonging to the surface edges will be deleted only if the meshes of the adjacent surfaces are deleted simultaneously or did not exist. The deletion function can also be used on entities (surfaces and/or curves) where meshing has failed and therefore no elements or nodes have been created. The deletion will make it possible to cancel the “constraints” accumulated on these entities by the different meshing criteria. It will then be possible to mesh these entities with new strategies (e.g. by increasing the size criteria) independently of the previous attempts to mesh.
Barycentric Smoothing This action is made available by clicking the Barycentric smoothing button or by selecting DeltaMESH -> Barycentric smoothing… from the Geometry menu. The Smooth dialog will then pop up.
This function is used to improve the finite element shape quality of the elements already generated, using an algorithm that repositions the nodes. Nodes belonging to the surface boundaries are not displaced. Only internal nodes are displaced, and repositioned exactly on the CAD geometry. This function can be used when better finite element shape quality is necessary: -
On the mesh of the blank holder surface, if volume modeling of the blank holder is chosen,
-
On the mesh of the blank.
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Notes:
·
This function must not be used on the mesh of die entry fillet and die bottom areas, because after barycentric repositioning the alignment of the nodes on the iso-parametrics is no longer preserved.
·
However, this function can be used on surfaces to improve the shape of elements comprising angles that are too acute or too obtuse.
The number of iterations performed by the barycentric smoothing algorithm can be defined in order to improve the quality iteratively. Three iterations are generally sufficient. Note:
·
The barycentric smoothing and repositioning operation on CAD geometry may be costly in terms of CPU time when there are a large number of elements or the CAD surfaces are complex. In this case it is preferable to leave the iterations number at 1, and if necessary restart the barycentric smoothing operation when the result has been examined.
Restore Eliminated Surface This function permits to restore the surfaces that have been eliminated during the joining session. These surfaces are either duplicated surfaces or thin surfaces. After the joining session, these surfaces cannot be meshed because there are out of the topological model. So, this tool permits to re-integrate the eliminated surfaces into the topological model. This action is made available by clicking the Restore surfaces button or by selecting DeltaMESH -> Restore surfaces … from the Geometry menu. The Restore Surface dialog
will then pop up. You can display the eliminated thin surfaces and the eliminated duplicated surfaces by selecting Show -> Thin surfaces and Show -> Duplicated surfaces in the 3D View contextual menu. If you consider that DeltaMESH has eliminated too many surfaces, you can select them and restore them into the geometrical model. To introduce them into the topological model, you have to complete the joining results (the thin/duplicated surfaces toggles will be deactivated).
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Part Splitting This action is made available by clicking the Part splitting dialog will then pop up.
button. The Part splitting
This function is used to split the part with a curve. It is possible to separate the part in two to apply two different mesh strategies (for hemming simulation for example), to make a hole, to delete a piece of part or to improve the CAD model directly in PamSTamp2G. However this function is available after the import session or after the joining session, it is recommended to use it after the joining session. Notes:
·
If this function is used after the meshing session, meshing information will be deleted.
The first field corresponds to the curve use. It is possible to use a curve present in the model (imported by DeltaMESH for example) or to draw a new curve with the curve manager. Notes:
·
The curve used must be closed or must cross at least two surface’s borders.
·
The curve must not intersect itself
·
If the curve is too far from the model, some faces may not be cut.
The second filed is facultative. It indicate in witch object cutting faces are send. If nothing is chosen, cutting faces replace original faces in their object.
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CONFIGURATION OF MESHING PARAMETERS Click the Advanced parameters button situated on the Meshing dialog to display the DeltaMESH parameters window containing the values of the various DeltaMESH configuration parameters. The roles of the various parameters are described below.
Parameters of the Geometry Tab
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Visualization panel
Modification of the display parameters will take effect immediately. A DeltaMESH session starts immediately once you have pressed the “Enter” key, in order to update the model display. You can then close the window again. -
Number of isoparam:
Number of iso-parametric curves to display the surfaces (default value: 1). By increasing this value it is possible to estimate the shape of surfaces more accurately and to detect surface parameter problems (iso-parametric curves very close to the edges, not regularly spaced, etc.).
-
Geom. Discretization:
This value represents the chordal error used to show surfaces (contours and iso-parametric curves) and curves (default value: 0.01). The lower this value is, the more faithful the representation of surfaces and/or curves will be, but the display time will also increase. (On workstations with graphic cards of limited performance it may be worth increasing this value to display large models).
Model panel
Modifications of these parameters will take effect only when the subsequent mesh is imported or joined. -
Reference space:
Size of the space containing the CAD model (default value: 4000) (in the automobile sector, 4,000 mm is a common value). The system's precision will be calibrated according to this parameter. The minimum allowed value for tolerances or dimensions specified in DeltaMESH (import tolerance, joining tolerance, element size, etc.) is computed based on this parameter and is equal to: Reference space x 10-5 (i.e. default value: 0.04). Therefore it is very important to modify this parameter if the size of the relevant part is far away from 4000, or if another unit of measurement is used (meter, µm, inch, etc.).
Joining panel
The following parameter is used by the joining algorithms. -
Split surface edges:
Splitting status of surface edges for joining operations. If this toggle is deactivated, joining will be performed without splitting the surface edges, so that only surfaces with coinciding nodes will be joined. This toggle must only be deactivated in very specific cases (activated by default).
-
Merge geometrical edges:
Merging status of surface edges for joining operations. If this toggle is activated, joining will concatenated successive tangent curves along a surface’s contour to form longer curves. This toggle must only be deactivated in very specific cases (activated by default).
Parameters of Meshing Tab The following parameters are used by the meshing algorithms to produce elements complying with a given level of quality.
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Criteria panel
-
Max. warping angle: Maximum
permissible warping value for quadrangular elements (default value: 10). During meshing, two adjacent triangles elements will only be transformed into a quadrangle if the warping of the resulting quadrangle is less than this value.
-
Merging triangle angle: Minimum
-
Max. validity angle: Maximum
-
Max. internal angle: Maximum
internal angle permitting two triangles elements to be associated to form a quadrangle (default value: 60). During meshing, two adjacent triangles will only be transformed into a quadrangle if the smallest internal angle of the resulting quadrangle is less than this value. angle between the normals of two adjacent elements (default value: 135). A surface's mesh will be considered invalid (and will therefore be rejected) if the angle between the normals of two adjacent elements is greater than this value. angle required inside an element (default value: 175). Above this angle, diagonals will be swapped to attempt to satisfy this criterion.
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Min. internal angle:
-
Apply mesh criteria on borders:
-
Force center curvature node:
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Minimum angle required inside an element (default value: 1).
When this check box is activated (default value), chordal error and angle criteria are also applied on surface border (with the same meaning as “follow isoparametric” option). This option is useful to simplify the mesh when borders’ respect is not important (mesh keep connected) When this check box is activated, this enables DeltaMESH to force node creation on borders’ curvature’s center to obtain a better mesh quality (default value: active). We recommend inactive it for very high definition model to not slow meshing.
Force center curvature node deactivated
-
Force mesh generation: When
-
Elongation limitation: Parameter
Force center curvature node activated
this check box is activated, this enables you to force meshing of a surface even if several elements do not comply with all the defined quality criteria (default value: active). When this parameter is active, we recommend you check surface meshing when an error is indicated in the report. enabling you to activate limitation of element elongation within a surface (default value: non active). When this toggle is active, the maximum element elongation must be entered in the Limit field (default value: 3). This parameter must only be activated in special cases (mesh of blanks…)
Quad. Surface detection panel
The following parameters are used to detect and mesh 3 or 4-sided surfaces (see subsection “Quadrangular surface detection function”). -
Corner limit angle:
Maximum value of the angle making it possible to detect corners of 3 or 4-sided surfaces (default value: 10°). A corner will be created if the external angle of two consecutive curves is greater than this value.
-
Distortion angle:
Maximum angular distortion (default 40°) of elements compared to perfect quadrangles. If one of the angles is greater than this value, the surface will not be selected as a 3 or 4-sided surface.
Over discretization:
Parameter concerning over-discretization of 3 or 4-sided surfaces (default value: active). This parameter defines the type of density progression within
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each surface. If it is activated, a larger number of elements will be generated within the surface (about 10%).
DELTAMESH Configuration of Meshing Parameters
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