Reply To: How to prevent rigid motion in ANSYS Static Structural?

[peteroznewman]

Yes, you have correctly applied the kinematic mount for the thermal load, but since you want to apply a pressure to the faces, you can't use three single nodes. Since your geometry and the loads have two planes of symmetry, you can use that in the constraints.
Use a plane parallel to YZ that goes through the center of the blocks Split the blocks using that plane and delete one half, keeping the blocks on the +X side. The cut faces get a Displacement BC of X=0 and Y, Z Free. That allows you to apply the pressure load on just one side and have a BC to push against.
It will be convenient to make a plane parallel to the XZ plane that goes through the center of the half blocks and split the blocks again. Delete half again, keeping the 1/4 blocks on the +Y side. Apply a Displacement BC on the newly cut faces of Y = 0 leaving X and Z Free.
There is one DOF left to constrain, which is motion along the Z axis. This could be achieved by selecting the faces on the +Z side of the quarter blocks and using a Remote Displacement, set Z = 0 leaving the other five DOF Free.