I have a fairly complex model, which includes a number of rigid elements used to simulate pin joints. Unfortunately, I can only successfully solve with AUTOMPC checked. I know that this means I have a conflict with my rigid elements or constraints, my constrains are relatively simple, so I'm confident the problem lies with one or more of the rigid elements, but I can't seem to identify the problematic rigid element. Is there any way to determine which DOFs Nastran is ignoring via AUTOMPC?
EDIT: according to the F06 file:
AUTOMPC PROCESSING COMPLETE
*** USER INFORMATION MESSAGE 2050 (ESCHEL)
AUTOMPC PROCESSING ELIMINATED 30 REDUNDANT CONSTRAINT EQUATIONS
That's the only information regarding the AUTOMPC feature I can find in the F06 file, the F04 file only tells me that it's been enabled. Is there any way to call for more specific information in the output?
Run the analysis without AUTOMPC checked, this way you will get written in the *.f06 file the conflicts witch RBE2 elements and you can modify your FEMAP model. To learn more about RBE2/RBE3 elements please visit my blog in the following address:
The following error message written in the *.f06 file means "double dependency error": you have a dependent grid node that is included in more than once RBE2 element, then the doule dependency error.
Another common error is to prescribe a constraint in any dependent grid node of an RBE2 element, this means FATAL error for sure!!.
USER FATAL MESSAGE 2101 (GP4) GRID POINT xxx COMPONENT x ILLEGALLY DEFINED IN SETS UM US