Good morning,
I have different questions about the software:
1- How can I understand where the problem is in the case of a fail? Is there a sort of debugger or log files that tell what could be the problem? (i.e. a missing BC, a not correctly defined contact);
2- How is defined the stress value displayed on a node? Is it a maximum or an average value among the different iterations?
Thank you.
Check the status file for warning and error messages from the solver. Unfortunately, it’s often the case that something doesn’t work in CalculiX but the solver doesn’t give any warning about it. If you get a message indicating a convergence issue, you can check the incrementation and residual data. But debugging often requires taking a closer look at the model and carefully examining all of its features.
Check this thread: Result Intepretation
What you get is (spatially) averaged nodal stress from converged iteration in a particular increment.