Cyclic loading a concrete bar

[ashutoshsonpal]

Dear All,

I am carrying out a displacement controlled analysis of a concrete bar (axial load, one dof only) based on the ConcreteCM model. I am loading it upto a displacement of 0.01" followed by unloading upto -0.01" and reloading back to 0". I am getting the following solver error:

WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 1
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at iteration: 0 with domain at load factor -0.000554312
OpenSees > analyze failed, returned: -3 error flag
0.00650000000000000230
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 1
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
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 1
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

Thanks in advance for your assistance!