I am looking for a way to deactivate elements when a limit criterion is reached. I still need to find out the limit criterion, but currently I think that it will be either a certain stress or strain.

It would be elegant to exclude the element directly from the stiffness matrix, but if this is not possible, an alternative would be to set the stiffness to zero (or to something very small, so that the solver can still solve the matrix).

I’m afraid that it won’t work in this case because it only removes elements that are initially defined by a user. Here the goal is to deactivate/delete elements dynamically, based on a failure criterion.

*MODEL CHANGE doesn’t seem to be meant for my case, because it activates contact elements. But I want to disable solid elements.

I have had a look at the User Material help (http://web.mit.edu/calculix_v2.7/CalculiX/ccx_2.7/doc/ccx/node255.html as well as the chapter 8.5 linked there), but can’t really figure out how to define one. Could someone give me a recommendation on how best to get started with this?

That is interesting. I still have CCX2.16. It says that *MODEL CHANGE only works for contact elements. In the help of 2.19 it actually says that all elements can be deactivated. Thanks for the correction.

That would really simplify the whole thing. However, there is still the challenge to combine all elements for which the error criterion (e.g. a certain elongation) to one set.

I don’t know of any command that can query the results of the last calculation step while solving.