From what I can see in the manual/documentation, CalculiX does not seem to include built-in cohesive behavior / cohesive zone modeling (CZM) for fracture (traction–separation law, cohesive elements, etc.).
Is there any known workaround to perform cohesive zone modeling in CalculiX (e.g., using contact, tie constraints, special element formulations, damage models, etc.)?
Are there any examples or tutorials (PrePoMax + CalculiX) demonstrating a CZM-like fracture approach?
If there is no practical built-in route, the last option would be implementing it via a UMAT or UEL:
3. Does anyone have experience implementing CZM via UMAT/UEL in CalculiX?
4. Can PrePoMax visualize results for elements defined through UEL (e.g., show element contours, damage/traction variables, element status, etc.), or are there limitations?
Any guidance, references, or example input files would be greatly appreciated.
Yes, CalculiX doesn’t have any CZM (unlike Abaqus). Might be better to ask for workarounds (especially involving subroutines) on its forum.
When it comes to workarounds with built-in features, there’s just no separation contact (not predefined, needs a specific setup) and you could add a thin layer of elements with a specific material model (including no tension or no compression, orthotropy and so on).