with and without zeroLengthContactNTS2D

[khatibi_m]

Hi

I considered soil-foundation-structure interaction. I modeled soil and foundation by quad element, and foundation was considered rigid. I used zeroLengthContactNTS2D element in my model for modeling slip between soil and foundation. first I did a eigenvalue analysis, and structure periods were acceptable. but when I did nonlinear dynamic analysis for model, the analysis was failed and not converge. this warning was displayed:

WARNING: CTestEnergyIncr::test() - failed to converge
after: 600 iterations
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 2.89
OpenSees > analyze failed, returned: -3 error flag


When I modeled soil-foundation-structure without zeroLengthContactNTS2D element in my model, analysis did successful.
the analysis commends in my model are:

wipeAnalysis
constraints Transformation
#test NormDispIncr 1.e-2 500 5
test EnergyIncr 1.e-2 600 5

numberer RCM

algorithm Newton
#algorithm ModifiedNewton
#algorithm KrylovNewton

#system BandGeneral
#system ProfileSPD
system SparseGeneral -piv

integrator Newmark 0.5 0.25

set massProportionalDamping 0.0
set stiffnessProportionalDamping 0.001
rayleigh $massProportionalDamping 0.0 $stiffnessProportionalDamping 0.

analysis VariableTransient

# Analysis duration of 20 seconds
# numSteps dt
set ok [analyze 2000 0.01]
if {$ok != 0} {
puts "analysis FAILED"
} else {
puts "analysis SUCCESSFULL"
}

Please help me.