4. Image-Based Simulation#
4.1. Introduction#
Image-based simulation is a technique which enables more accurate geometries of components to be modelled. Imaging techniques, such as X-ray computed tomography (CT) scanning, enable the characterisation of internal features within a component, from which a more accurate mesh can be generated compared with an idealised CAD-based equivalent. These methods are able to capture features present due to manufacturing methods, such as asymmetry or micro-cracks, yielding simulations with increased accuracy. That is, image-based meshes allow simulations of components ‘as manufacutred’ rather than ‘as designed’.
4.2. Sample & Simulation#
In this example, a CT scan of a dog-bone sample is used in a tensile test. The image-based mesh used for this simulation can be downloaded here. See www.ibsim.co.uk for further information on the image-based simulation methodology.
4.3. Task 1#
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()
Ensure that the downloadedi mage-based mesh has been saved to the following location Output/Tensile/Tutorials/Meshes/Tensile_IBSim.med
Launch VirtualLab using the following 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 non-idealised Tensile_IBSim mesh compared with an idealised CAD-based mesh.