Dirichlet boundary conditions on a plane to rotate

[ateixeira0163]

Hi!
I looked into the examples and documentation and I couldn't figure it out if it was possible to rotate just one plane of an object (a rod for example). I saw the Problem: ElasticTorsion that seemed appropriate but I didn't found any examples nor I managed to make it work. Is this the way to do it or is there another way to apply a rotation to one face of a rod?
Best regards,
Alex

[teseoch]

PolyFEM supports expressions as BC.

Here is an example for rotation:
https://github.com/polyfem/polyfem-data/blob/70d06f69180a437cf9e37311ee05c6707c28c922/contact/examples/3D/stress-tests/rod-twist.json#L79

[ateixeira0163]

I saw this example, but it would to turn only the face ("id":1 or "id":3) on the z-axis. Like translating and rotating with dependence on time [dx(t), dy(t), dz(t), rx(t), ry(t), rz(t)] (d → translation, r → rotation)