Learning Forum

[EagerToLearn]

Hello everyone,

I was wondering if you could help me regarding the best practice of 2D failure simulation of RVEs?

I have the following composite:

[Bill Bulat]

Hi Mike The shear forces can be applied to each face:
The pressures may be applied to the two end faces as shown:
I named the faces that go around the perimeter:

A command object was used to apply periodic BCs

Please look up the CPCYC command in the Mechanical APDL Help.
Though the applied pressures and traction loads should cancel each other, the structure is not adequately supported. I used an elastic support on all external faces with high stiffness (experiment with values to find one that doesn't results yet prevents excessive motion).

I discovered that the Mechanical GUI would not allow me to apply forces to periodic boundaries, which is why I instead used a command object to define periodicity as a workaround. Also, Match Control wouldn't allow me to force identical meshes on both the xmin/xmax and ymin/ymax surface pairs simultaneously. If you define mesh size on opposite faces, this almost always results in identical meshes, which in turn allows CPCYC to define periodicity with coupled degree of freedom sets.
Best Bill

[EagerToLearn]

Hi Bill thank you very much. Unfortunately the command does not seem to create periodic boundary conditions (here is an example of what I want to do: Theory of Periodic Boundary Condition implementation in FEM - YouTube)
"I discovered that the Mechanical GUI would not allow me to apply forces to periodic boundaries, which is why I instead used a command object to define periodicity as a workaround".
How did you originally enforce the periodic boundary conditions before you used the workaround? As far as I can tell other researches only applied the loads to the corner nodes (as shown for example in the video), which is maybe why the GUI did not allow you to apply forces to PBC.
I am looking forward to your answer.
Regards
Mike