what is this error mean ?

[yangya]

WARNING: CTestEnergyIncr::test() - failed to converge
after: 6 iterations
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
StaticAnalysis::analyze() - the Algorithm failed at iteration: 7 with domain at
load factor 0.8
OpenSees > analyze failed, returned: -3 error flag



what is this error mean....

PLZ , solution.....

my brief script..

set Tol 1.0e-6;
constraints Plain; # how it handles boundary conditions
numberer Plain; # renumber dof's to minimize band-width (optimization), if you want to
system BandGeneral ; # how to store and solve the system of equations in the analysis (large model: try UmfPack)
test EnergyIncr $Tol 6 ; # determine if convergence has been achieved at the end of an iteration step
algorithm Newton; # use Newton's solution algorithm: updates tangent stiffness at every iteration
set NstepGravity 10; # apply gravity in 10 steps
set DGravity [expr 1./$NstepGravity]; # first load increment;
integrator LoadControl $DGravity; # determine the next time step for an analysis
analysis Static; # define type of analysis static or transient
analyze $NstepGravity; # apply gravity

[fmk]

it means the analysis failed at the 8'th step. do something in the script.

see
http://opensees.berkeley.edu/wiki/index ... r_Analysis