elasticPPGap issues

[nicobu]

Hi,

I am trying to run a very simple script in order to test the behavior of the elasticPPGap material, unfortunately Opensees returns the following error message:

WARNING FullGenLinLapackSolver::solve() - lapack solver failed - 1 returned
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
StaticAnalysis::analyze() - the Algorithm failed at iteration: 20

Please help me trying to find my error.

Thank you.


This is the code I am running:

##############
wipe
model basic -ndm 1 -ndf 1

node 1 0.0
node 2 0.0

fix 1 1
fix 2 0

set sCellFy [expr 30000.0];
set sCellDy [expr 0.002];
set sCellHard 0.001;

uniaxialMaterial ElasticPPGap 1 [expr $sCellFy/$sCellDy] $sCellFy 0.0 $sCellHard damage

element zeroLength 1 1 2 -mat 1 -dir 1

recorder Node -file Node2.txt -time -node 2 -dof 1 disp

pattern Plain 1 Linear {load 2 1.0}

test EnergyIncr 1.0e-3 100 1
algorithm Newton
system FullGeneral
constraints Plain
numberer RCM

integrator DisplacementControl 2 1 0.0001
analysis Static
analyze 30

integrator DisplacementControl 2 1 -0.0001
analyze 60

[fmk]

you have a 1d spring model with a single material, should the material return a 0 for the tangent at any stagfe, the solver is going to fail!

throw it in parallel with something.

[nicobu]

Thank you. I thought that the displacement control integrator could deal with 0 stiffness.

[fmk]

no. it adds the reference loads, determines what the change in displacement would be as a result of this by solving the matrix equation, and then modifies the load factor based on that response.

[clairelove]

Hi,have you solve your problem yet? I have been studying the PPGap material but I find it hard to kown how it works and how to set proper values. I'm using this material for the expansion gap in a bridge. can you give some suggestions?

nicobu wrote:
> Hi,
>
> I am trying to run a very simple script in order to test the behavior of
> the elasticPPGap material, unfortunately Opensees returns the following
> error message:
>
> WARNING FullGenLinLapackSolver::solve() - lapack solver failed - 1 returned
> WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in
> solve()
> StaticAnalysis::analyze() - the Algorithm failed at iteration: 20
>
> Please help me trying to find my error.
>
> Thank you.
>
>
> This is the code I am running:
>
> ##############
> wipe
> model basic -ndm 1 -ndf 1
>
> node 1 0.0
> node 2 0.0
>
> fix 1 1
> fix 2 0
>
> set sCellFy [expr 30000.0];
> set sCellDy [expr 0.002];
> set sCellHard 0.001;
>
> uniaxialMaterial ElasticPPGap 1 [expr $sCellFy/$sCellDy] $sCellFy 0.0
> $sCellHard damage
>
> element zeroLength 1 1 2 -mat 1 -dir 1
>
> recorder Node -file Node2.txt -time -node 2 -dof 1 disp
>
> pattern Plain 1 Linear {load 2 1.0}
>
> test EnergyIncr 1.0e-3 100 1
> algorithm Newton
> system FullGeneral
> constraints Plain
> numberer RCM
>
> integrator DisplacementControl 2 1 0.0001
> analysis Static
> analyze 30
>
> integrator DisplacementControl 2 1 -0.0001
> analyze 60