Dear all,
I conducted a dynamic analysis for a 2D RC frame. I received some error messages (pasted below) for some ground motions, however, the analyses converged successfully.
I would like to know whether I can rely on the results or not.
Number of Stories in Z: 5; Number of bays in X: 2; Number of bays in Y: 1
Periods-----------------------------------
TI = 0.29608937147596304
TJ = 0.094325037355977
TK = 0.051041719561029444
TL = 0.04330567488604579
TO = 0.03738064780199499
------------------------------------------
Model including gravity loads has been built.
---------------------------------------------------------
1
2
Proceeding for dynamic analysis
---------------------------------------------------------
GMfiles/EQ2.at2
WARNING: CTestEnergyIncr::test() - failed to converge
after: 2000 iterations
current EnergyIncr: 8.70917 (max: 0.0001) Norm deltaX: 0.043728, Norm delt
aR: 94724
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 8.86
OpenSees > analyze failed, returned: -3 error flag
WARNING: CTestEnergyIncr::test() - failed to converge
after: 2000 iterations
current EnergyIncr: 8.70917 (max: 0.0001) Norm deltaX: 0.043728, Norm delt
aR: 94724
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 8.86
OpenSees > analyze failed, returned: -3 error flag
WARNING: CTestEnergyIncr::test() - failed to converge
after: 2000 iterations
current EnergyIncr: 8.79118 (max: 0.0001) Norm deltaX: 0.037313, Norm delt
aR: 94726.4
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 9.28
OpenSees > analyze failed, returned: -3 error flag
WARNING: CTestEnergyIncr::test() - failed to converge
after: 2000 iterations
current EnergyIncr: 8.16333 (max: 0.0001) Norm deltaX: 0.0600174, Norm del
taR: 68834.9
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 9.645
OpenSees > analyze failed, returned: -3 error flag
WARNING: CTestEnergyIncr::test() - failed to converge
after: 2000 iterations
current EnergyIncr: 9.14575 (max: 0.0001) Norm deltaX: 0.0505147, Norm del
taR: 94878.1
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 10
OpenSees > analyze failed, returned: -3 error flag
Ground Motion Done. End Time: 60.005000
Periods-----------------------------------
TI = 0.3982268138788215
TJ = 0.112598385967635
TK = 0.05953849827673746
TL = 0.047726944090862734
TO = 0.04170964431832845
------------------------------------------
analysis done
----------------------------------
TOTAL TIME TAKEN 0:26:40
Thank you for your suggestions.
Convergence problem
Moderators: silvia, selimgunay, Moderators
Re: Convergence problem
without looking at your script one cannot say. It looks like the sccript is taking actions if the analysis fails at a step to get past that point. if you are happy with what it is doing then it is fine. If you do not know what it is doing, then i suggest you actually jhave a look at the script to see what it is doing to ensure you are satisfied with the steps YOU ARE INSTRUCTING the program to do. This is not OpenSees doing something that you have instructed it to try, it is not coming up with the remedy by itself!