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Hi,
I have a 2D eccentrically braced frame,when I remove all springs,the period is big (2828900s).when I have springs and their nodes and equalDOFs,I see this error
WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 1
and period is 960.32 s.
Where is my problem?

Thank you

Hi, I've analyzed irregular and regular structures by IDA.fragility curves show that probability of exceeding at each performance level at irregular structure is less than regular structure!! Shouldn't it be reverse? Irregularity is about rigidness of model,not mass.I concentrate mass of story at no...

Thanks a lot.

Thank you so much
Only an another question,shouldn't I use elastic element for beams and columns or it doesn't affect on result of IDA curve?

Hi, I have a 3D eccentric braced frame and I analyzed it using IDA,but drifts are very small in stories even at big accelerations such as 3.g!!! Why? Is that why analysis doesn't converge successfully? I use steel02 material (fatigue only for brace),fiber sections and nonlinear elements and also con...

hi,
Do anybody know the value of "c" and "D" parameters in MIK model(exponent for basic strength deterioration and rate of cyclic deterioration for loading)?
c = 1.0 for no deterioration
c=? for deterioration
Thanks a lot

Hello, I have a 2D 5-story steel frame.braces are modeled by fiber model and beams and columns are modeled by modified Medina Ibarra Krawinkler model.Although push-over curve seems reasonable and is coincident with push-over curve in SAP2000 program, but when I perform IDA analysis,IDA curve (PGA(g)...

Hello, I have a question about modeling.how can I assign Modified Ibarra Medina Krawinkler model to brace so that correct reaction is recorded?I mean how to model the inclined spring!I've already tried it by zeroLength element and constrained it by elastic material with high hardening, but result is...

here is a summery of my sketch,specially in base nodes:
https://drive.google.com/file/d/0BxSrrh ... sp=sharing
thanks a lot

thank you very much.
Do you mean the common node?as I said the curve is very strange!!in your opinion,above figure is reseanable?

hi, I have a problem with recording base reaction.when I model a column by elastic element and a brace connecting it at base by concentrated plasticity spring,how I should record reaction at their common node? when I record only reaction of spring,I get less strength,but I see strength degradation, ...

I've gotten this error already,because the value of second strain should be bigger than first strain,third strain should be bigger than second strain.

Finally,I obtained this curves after checking record and rigidDIiaphragm... in the one-story model: https://drive.google.com/file/d/0BxSrrhykAKlkaUZWSWdzZGs4bEU/view?usp=sharing but in 5-story model,the Opensees curve is too bad: https://drive.google.com/file/d/0BxSrrhykAKlkeHZ6amtHMENaSkk/view?usp=...

Hello, I couldn't find the problem in 3D model unfortunately,In addition I can't see strength degredation in the OPENSEES curve too! I'll be grateful in the event that anybody can help me! Here is script for 3D one story model(3X3-bay): wipe wipeAnalysis model basic -ndm 3 -ndf 6 file mkdir Record s...

many thanks for your helping!