MVLEM convergence Problem

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xantis85
Posts: 16
Joined: Tue Sep 06, 2011 7:54 am
Location: FedericoII

MVLEM convergence Problem

Hi,
I've a problem when running the opensees example for MVLEM. The output is:

"WARNING: numeric analysis returns 1 -- Umfpackgenlinsolver::solve
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at iteration: 0 with domain at load factor 0.1
OpenSees > analyze failed, returned: -3 error flag

Model generated and gravity load applied successfully
...
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 2
...
Trying Broyden ..
Trying NewtonWithLineSearch ..
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 2
DisplacementControl::newStep(void) - failed in solver
StaticAnalysis::analyze() - the Integrator failed at iteration: 0 with domain at load factor 0
OpenSees > analyze failed, returned: -2 error flag
PROBLEM Cyclic analysis: CtrlNode 017, dof 1, Disp=0.0000 inch"

any idea why the example does not work?

I also have another questions:
In the example in OpenSees site, for both the MVLEM and the SFI-MVLEM model, the comparison between TEST and SIMULATION leads to a significant difference in response when failure occurs for the Wall.
Since I would like to simulate the behavior of a frame-wall model until the collapse, I don't want to use the conventional definition of shear wall collapse based on the attainement of the Shear resistance for wall. I'd like to use a criterion based on the shear response drop of about 20%. Is this possible with these elements or there are other elements to simulate this behavior using the dynamic analysis? In original dispbeamColumnINT model by Massone the drop was evident, but it doesn't work when simulating the dynamic behavior.