Thermal- Mechanical Simulation

[wal657]

Hi, I am new to PYmapdl and am trying to run a static thermal mechanical simulation. I have set up the thermal portion and apply a temperature load on my geometry. I then want to use this temperature load on the same model as my imported load, but now introducing my structural BC to determine displacments and stresses on the geometry.

1. From my understanding I need to use the mapdl.clear command in between the thermal and structural portion. Is there an efficient way to reuse the same geometry I have already defined, along with the mesh without repasting it?
2. I am also unsure of workflow steps and whether the solution step should be started before applying the structural BC.

[mikerife]

Hi @wal657
Please see the Mechanical APDL Help -> Coupled Field Analysis Guide. There are several ways of modeling this and which you choose will change the answers to these and other questions.

It sounds like you have possibly decided on this, but MAPDL has both strong and weak coupling. Meaning that the models element type could solve the structural and thermal degrees of freedom at once (strong coupling). Or we can use the results of one analysis (thermal) as loads to a second analysis (structural). This second is 'weak' coupling.

Using 'weak' coupling we can use ETCHG command to change the element type from thermal to structural...possibly. Most likely. It depends on the element type(s) used. But the point is that there is no need to recreate the geometry (no need for the /clear command)...nor a need to remesh. Just change the element type. And well make sure that the material models include both structural and thermal properties. And the like.

Another way would be to clear the mesh and redo changing the physics. You could save the MAPDL database once the geometry is created, say to 'geometry.db' and resume it as needed for meshing for the different physics.

As you can see there are a few decisions to make first.

Saving a MAPDL database with just the geometry is one answer to your first question. Another answer would be to make the geometry creation a Python function that you can call as needed.

For the second question the workflow will partially depend on the coupling method choosen.

Mike

[wal657]

Thank you!