Boundary conditions and external torque implementation for a simply supported rod

[Srishti-Siddharth-iitb]

For one of my applications, I wish to simulate the Cosserat rod with the following boundary conditions:

1. Base of the rod: Position $r=[0;0;0]$ is fixed, the orientation $Q \in $ SO(3) is free, and there is an external torque (only at the base) to rotate the rod.
2. Tip of the rod: free, no external forces or torques.

I have attached a figure explaining the setup. Could you please let me know how to simulate this rod using PyElastica?

[armantekinalp]

Hey

You can use GeneralConstraints as a boundary condition in PyElastica. Please see the documentation.

For the rotating torque you have to write a custom forcing class for you application. Please see EndPointForces class here. Although this forcing classs applies tip force, implementation wise it is very similar to your application.

[armantekinalp]

I am converting this to a discussion since it is not an issue.

[Srishti-Siddharth-iitb]

Thank you. I have another follow-up question: do we have to add an external force or an external couple to simulate the torque at the base?