Tutorial 6: Crash - Explicit solution of an impact problem Laurence Marks
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1.
Geometry Import
Import the geometry in the form of a sat file – Tutorial 6.sat
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2.
Material and section properties
Start to define the material properties – go into the properties module. module Define two materials – Steel which will only have linear properties and Aluminium which will have yield and post yield behaviour. As the problem is dynamic we w also need to define a density for both. 7.8e-9 Steel – E = 210e3 MPa, NUXY = 0.3, Density = 7.8e Aluminium – E = 70e3 MPa, NUXY = 0.3, Density = 2.5e 2.5e-9 The aluminium plastic properties are as follows;
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Create section each for Aluminium and Steel. The aluminium section needs to be defined as a shell and include the shell thickness of 1.2mm.
Assign the sections to the relevant parts. Steel – Block and Aluminium – Crash Box. Go into the assembly module to instance the parts.
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3.
Define the first analysis step
For this analysis we shall choose a dynamic explicit step. Set the total time to 0.02 and accept the other default options.
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4.
We now define the contacts
In this model we are going to use a general contact. This contact definition tells the model to detect contact between all surfaces and also self contact. Friction and other interface properties are defined using the same interface property approach as used previously.
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5.
Define restraints straints and initial velocity
Restrain the rear face of the aluminium tube. Choose encastre – fully fixed.
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We use a predefined field to apply the initial velocity to the steel block. Define 25,000 mm/second in the z direction.
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6.
Meshing
Mesh the model with an appropriate mesh size so that it roughly looks like this.
7.
Create and nd Submit a job
Exactly the same method as the previous tutorials tutorials.
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8.
Open the results file and plot the results
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Strategic Simulation & Analysis Ltd Southill Barn, Southill Business Park, Cornbury Park, Charlbury, Oxfordshire, OX7 3EW T. 01608 811777 F. 01608811770
[email protected] W. www.ssanalysis.co.uk
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