hi everyone,

this is a displacement controlled problem. right hole if fixed and left hole is applied a delta-u step by step. I want to calculate the traction on the left hole.

thanks in advance

hi everyone,

this is a displacement controlled problem. right hole if fixed and left hole is applied a delta-u step by step. I want to calculate the traction on the left hole.

thanks in advance

Hi, I covered this recently here https://comet-fenics.readthedocs.io/en/latest/demo/tips_and_tricks/computing_reactions.html

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Thanks a lot. it works!

Hello bleyerj,

Thank you for your valuable link. Your link explained how to calculate the force on a Dirichlet boundary (the left clamped boundary in the link). But if the Dirichlet boundary is imposed on a point, do you know how to calculate the force on it? Thank you very much in advance.

It works exactly the same using the work of internal forces.

You cannot do it with the first method using the postprocessed stress since the stress at a given point is not well defined. You could project it on a suitable function space but this will induce a lot of errors, unwanted averaging, Gibbs phenomenon etc.

I understand now. Thank you very much.