Singular Matrix error in Transient analysis

[erahmani]

Dear Frank,

I have a big model of a partition wall with various types of elements, links, and constrains. I am using "system UmfPack" since my model is vary large. The model works fine in static analysis (gravity loading). The periods are also reasonable. However, when I want to run Transient analysis (for lateral load), the OpenSees shows an error : "UMD2FA: matrix is singular".
I appreciate if you can help me with this error.

Best,
Esmaeel

[fmk]

is it at the first step of the transient analysis?

[erahmani]

yes, it is.

[fmk]

what do you change between end of static and transient? .. inclusion of mass into matrix equation should not cause the solver to fail.

[erahmani]

Thanks Frank for your response.
I do not change anything.
Anyways, I could solve the error by trial and error. I still do not know what was the issue, but I have changed the way that I have modeled my specimen and now it works.

[erahmani]

I have a new warning. I receive warning "Warning: CTestNormDispIncr::setEquiSolnAlgo() - no SOE" when I use Newton with Line Search Algorithm. I should mention that I am using the system command before the test command. Also, I do not see the warning if I change the algorithm to something else, like Newton.
Could you please help me with that?