Constrained vertex on fault error

Hi, I am getting this error using a modified version of example 06 in hex8. This is the same code I modified at the workshop, I am just implementing it on a new mesh, which seems to be the issue. The error seems clear, I just do not understand what constrained means in this context.

"RuntimeError: Vertex with label ‘69102’ on negative side of fault ‘fault’ is constrained.

Fault vertices cannot be constrained."

Thank you for your help,


You cannot have an overlap between a Dirichlet boundary condition and the fault. In other words, you have one or more vertices that are in a nodeset for the fault and in a nodeset for a Dirichlet boundary condition. The remedy is to remove the nodeset for the Dirichlet boundary condition. You can use group boolean operations on groups in CUBIT/Trelis for this.

Here is how we create a nodeset face_zeg_nofault which has all vertices on the -z boundary that are not on the fault from the group face_zneg (all vertices on the -z boundary) and group fault (all vertices on the fault):

group "face_zneg_nofault" add node in face_zneg
group "face_zneg_nofault" remove node in fault
nodeset 16 group face_zneg_nofault
nodeset 16 name "face_zneg_nofault"

thank you – that did it.
Script is running now and producing desirable results.