COSMOSWorks help - singular matrix error
COSMOSWorks help - singular matrix error
(OP)
Hi,
I'm trying to run a study in COSMOSWorks on an assembly and I get an error which says "Singlar Matrix Error. Restraints may not be sufficient"
I cannot figure out what is causing the error. Everything is contrained properly and no parts of the assembly can move. I have tried multiple combinations of restraints and I keep getting the error.
Any help is much appreciated. Thanks.
I'm trying to run a study in COSMOSWorks on an assembly and I get an error which says "Singlar Matrix Error. Restraints may not be sufficient"
I cannot figure out what is causing the error. Everything is contrained properly and no parts of the assembly can move. I have tried multiple combinations of restraints and I keep getting the error.
Any help is much appreciated. Thanks.






RE: COSMOSWorks help - singular matrix error
Otherwise a singularity in the stiffness matrix means you have a zero in the diagonal. If it's not restraints then it might be zero stiffness from material property definition.
corus
RE: COSMOSWorks help - singular matrix error
Should I try a different material? Or, do you think it could be the case where the restraints are not sufficient and allow rotation? I am pretty sure the restraints I have do not allow rotation, but I could be wrong - wouldn't be the first time.
Thanks again, I appreciate the response.
RE: COSMOSWorks help - singular matrix error
corus
RE: COSMOSWorks help - singular matrix error
Corus hit a good point when he pointed out the issue of the contacts: be careful that SW's assembly "constraints" are meaningless in FEM: even if your parts are geometrically fully restrained, if you don't check for correct set up of contacts in Cosmos then you probably will get stuck with rigid body motion. As contacts are resolved by the end of the solution preconditioning, this might explain why you get the error at 90% or more of the preconditioning.
Regards
RE: COSMOSWorks help - singular matrix error
Thanks to both of you for the helpful posts which led me to figure out what was going wrong - much appreciated!!!