Thanks for your reply. but I don't quite understand how to connect BC to truss element, Can you please explain more in details? Because in my model, I'm using CPE4 elements with XFEM. SO when damage initiated I want to impose a fixed BC condition. So my purpose is not to relax boundary...
Yes, that is exactly what I want. before the time of failure, the element behaves normally, but when the stress/strain reaches a critical value, it will fail. and them I want to make the nodes of the failed element fixed from then on (for example, a minor crack is generated during the analysis...
Thanks for your reply. I know there's big limitation on *Boundary keyword, I'm thinking of use subroutine to get around, for example, can I define the failed element in the previous step in a single element set by some subroutine, and then use *Boundary, Fixed in the next step.
I know how to do...
I'd like to set fixed boundary conditions on some element, but not at the beginning of simulation, but during the analysis.
I want to impose fixed boundary conditions on these failed element during analysis,
however, the *boundary keyword has the format:
*Boundary, Fixed or *Boundary, USER...
