dear madam or sir there,
i got a question when doing the spectral fatigue analysis of a offshore jacket structure, an error occured during the step of extract mode shapes analysis.
it showed the following msg:
***ERROR IN MATRIX DECOMPOSITION
ROW 170 HAS ZERO OR NEGATIVE TERM = -0.649092D+12
MATRIX IS NON-POSITIVE DEFINITE
OCCURS AT JOINT P311 FOR Y ROTATION
i want to tell you that a psi input file was used in the first step of creating linear foundation. however the inplace static analysis, dynamic analysis and seismic analysis
can be runned correctly with the same psi input files.
i can send you the input files if needed, looking forward to your reply. thanks.