I created a simple component mode synthesis model with a CBN method, but the stiffness matrix that I exported in a *.pch file has a determinant of zero. This is causing my model to be ill-conditioned.
I tried finding where the cause of this problem was, and I came across these warnings. I'm note sure what they mean, but they led me to set AUTOSPC to No.
When I did this however, I ran into similar problems where I got this message that the boundary nodes have no stiffness.
How can I resolve this problem, so the rotational degrees of freedom have a nonzero stiffness, so these messages go away, or what other ways are there to fix my stiffness matrix, so it is not singular? The element property type I am using is PSOLID.
Thank you
