Tutorial 4#

Image-based simulation is a technique which enables more accurate geometries of components to be modelled. Imaging techniques, such as X-ray or computerised tomography (CT) scanning, enable the visualisation of internal parts of a component, from which a more accurate mesh of the component can be generated compared with an idealised CAD-based version. These methods are able to capture imperfections in a component, such as asymmetry or cracks, yielding more realistic results from the simulation.

In this example a CT scan of a dog-bone component is used in a tensile test. The image-based mesh used for this simulation can be downloaded here.

Action

The RunFile RunTutorials.py should be set up as follows to run this simulation:

Simulation='Tensile'
Project='Tutorials'
Parameters_Master='TrainingParameters_IBSim'
Parameters_Var=None

 VirtualLab=VLSetup(
                Simulation,
                Project)

 VirtualLab.Settings(
            Mode='Interactive',
            Launcher='Process',
            NbJobs=1)

 VirtualLab.Parameters(
            Parameters_Master,
            Parameters_Var,
            RunMesh=True,
            RunSim=True,
            RunDA=True)

 VirtualLab.Mesh(
            ShowMesh=False,
            MeshCheck=None)

 VirtualLab.Sim(
            RunPreAster=True,
            RunAster=True,
            RunPostAster=True,
            ShowRes=True)

 VirtualLab.DA()
 VirtualLab.Voxelise()
 VirtualLab.Cleanup()

Ensure that the image-based mesh downloaded has been saved to the following location Output/Tensile/Tutorials/Meshes/Tensile_IBSim.med

Launch VirtualLab using the followign command:

VirtualLab -f RunFiles/RunTutorials.py

Looking at Input/Tensile/Tutorials/TrainingParameters_IBSim.py you will notice Sim has the variable ‘Displacement’ but not ‘Force’, meaning only a controlled displacement simulation will be run.

From the results shown in ParaViS you should notice the asymmetric nature of the displacement, stress and strain profiles. These are as a result of the subtle imperfections in the Tensile_IBSim mesh compared with an idealised CAD-based mesh.

You will also notice the Parameters file also has a new namespace Vox