treem22 |
November 13, 2021 21:49 |
How do I pre-stress a simulation?
I note and greatly appreciate bigphil's recent addition to the tutorials showing how to restart a simulation:
https://bitbucket.org/philip_cardiff...-restart-gives
And now I'm wondering about another type of analysis -- how to pre-stress a solid.
I am attempting to take the solid/linearElasticity/pressurizedCylinder tutorial solution (at time = 10s) and use it as an "initial" state for a subsequent simulation. Following the example from the recently release tutorial, I can restart the simulation from time = 10s, but all of my displacements and strains will be measured from the time = 0s state.
What I think I should be able to do: - solve the pressurizedCylinder tutorial as normal
- use paraview to obtain the deformed cylinder shape and then mesh this new geometry
- map the sigma values from to tutorial solution to an initial condition of a new simulation
- reset the displacement values such that the new simulation begins with 0 displacement (0/D is initialized to 0 everywhere)
- apply the same pressure as the pressurizedCylinder tutorial
- observe that there is no further deformation of the cylinder because the pre-stresses I mapped equilibrate to the applied internal pressure
This is not happening, and I'm wondering why. I hoping someone here who knows more can shed some light.
Ideas I've had for why this doesn't work: - My understanding of continuum mechanics is flawed and applying a pressure to a pre-stressed deformed object is not the same as continuing to apply the same pressure to a simulation solution
- The sigma values I'm mapping in aren't contributing to the new simulation solution at all. I see that they are read in if present (src/solids4FoamModels/solidModels/solidModel), but maybe they aren't considered at that first time step, or maybe I need to apply something other than the "calculated" boundary condition
- the linearGeometryTotalDisplacement solidModel doesn't allow for pre-stressing; maybe only solidModels that use DD allow for pre-stress
Any ideas?
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