The OpenSees Community

Hi, I want to extract plastic rotations of beams and columns of a RC building. The beam and column elements of this structure were divided into 10 sub-elements. I got curvature from the first and last elements of each beam and column. The recorded curvatures minus the yield curvature give the plasti...

Yes it means that the responses of second stage and third stage are about same and in this case the third mode does not have any effect on response of the structure (18-Story RC building).I use loadconst at the end of each stage.It is correct to use loadconst at the end of each stage, am I right??

But the results don't show that and its strange. the script is same but the third mode doesn't work in RC building.Can it be due to modeling or not? How can I fix it?

Hi, I do a 2-stage pushover analysis which 1st stage load pattern is first mode shape and 2nd stage load pattern is 2nd mode shape.In this pushover method,the initial condition in the second stage is the same as the state at the last step of analysis in the first stage. Also, I do a 3-stage pushover...

hi, I want to do a 2-stage pushover analysis which every stage has different load pattern.In this pushover method,the initial condition in the second stage is the same as the state at the last step of analysis in the first stage.When the structure pushed by this method,the pushover curve shows a dro...

Thanks a million Mr.selimgunay.

As I mentioned earlier the jaggedness of pushover curve solved by incremental update of load but again the period variation exists.what is the problem?

Thank you for your prompt reply dear fmk, I get part of my question but again I don't know what is the reason of rising and falling of period at post peak.For example the period rises to 10s at one step then falls to 5s at subsequent step and this procedure continiues until the eigen gets negative. ...

hi dear fmk, To solve this problem, I write a script to add load gradully.In this case the load vector of each step is the "summation of previous load vector and a factor of new load vector" and I take this factor=0.1.When I do this, the pushover curve gets normal but again there is period variation...

Hi, I do an adaptive pushover analysis for a RC building and I extract pushover curve.But after a specific displacement the pushover curve gets jagged and the period of the structure changes to either higher value or lower value in subsequent steps.So my question is,are the results of this analysis ...

Hi everybody,
As you know Total updating in Adaptive pushover analysis encounters with divergence in some structures specially high-rise buildings.So we can use Incremental updating instead.Can anybody help me to write the script of this analysis?

Hi everybody, In displacement-based pushover analysis for a typical 2D frame, should we apply displacement pattern(with sp command) to all main nodes of each story or just the side node at each story? It's good to say that I tried both of them. In terms of displacements and drifts both method gave s...

Thanks Mr.Selimgunay for your answer.Yes your right.In accordance to section 13.8 of "Dynamics of Structures" of Chopra, we have 2 alternative for doing RSA.One of them is the way you explained and the other one can be done by means of some equations (equations 13.8.1a & 13.8.1b of the Aforementione...

I mean response spectrum analysis(modal analysis) of MDOF system.I need it for "Extended N2" pushover method.
Thanks for your immediate attention.

Hi,
Can anybody explain briefly how Response Spectrum Analysis should be done in opensees?????
I checked all topics related to this issue but I could not get my answer!!!!!
Thanks.