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[quote="horizon"][quote="silvia"]your analysis time step definitely has to be less than your ground-motion step.[/quote] yes, my analyses time steps are less than or equal to input motion's dt but still produces very different results.[/quote] hi all, I think I've figured out the...

[quote="silvia"]your analysis time step definitely has to be less than your ground-motion step.[/quote]

yes, my analyses time steps are less than or equal to input motion's dt but still produces very different results.

[quote="silvia"]what is the time step of the input motion?[/quote]

0.005 for two input records and 0.02 for the other one.

the record's dts and PGAs listed together with the results in my first post.

[quote="silvia"]it makes sense that as you increase the time step you might miss critical peaks.
you should plot all three time-history responses and see.[/quote]

already done! no peaks missed.
last two time steps are too small, 0.001 and 0.005. but the results very different, esp. disp.s

Hi everyone, My structure is a 20-story RC frame in 2D. I've run nolinear dynamic analyses under three records with three analysis time steps (0.02, 0.005 and 0.001). I've monitored the disp.s and acc.s of a node @ 20th story. The results are very different: RECORD PROPERTIES ANALYSIS STRUCTURAL RES...

Hi all,
Is it possible to apply velocity or displacement record as uniform excitatioin to the structure in nonlinear analysis?
Bests

Hi all, I can run nonlinear time history analysis under an earthquake excitation with a 0.1g-PGA.But once I applied a relatively bigger ground motion it fails after a certain time step...Do you think that it because of the weakness of the structure? I mean the structure can stand with a certain leve...

Dear All, Does anyone has any experience wtih OpenSees and GID? Have you ever tried to build a geometry by GID and then transfer it to OpenSees?On the other hand, does GID allow to transfer SAP200 data into OpenSees? By the way, we were planning to buy GID software and I asked GID guys to make a 50 ...

hi all,
is there any command to see what i've already modeled (undeformed shape, deformed shape, mode shapes etc.) on the screen?

Dear Frank, I am using Concrete01 material for my 3D building and have similar problem.I added "-iter 10 1e-1" to each nonlinearBeamColumn element but it didn't work.After a few steps the analysis is terminated with the same error message: failed to get compatibel force&deformations fo...

Dear All, I am working on modeling of a four-storey RC "moment resisting frames+shear walls" building in OpenSees and going to run lots of nonlinear time-history analyses.On the other hand, I have the model of the building in SAP2000.In OpenSees, first time I used elastic frame sections to...

Dear all, I just started to model a 3-dimensional 4-storey RC building consisting of moment-resisting frames and shear walls.I'd like to run first a linear analysis and then nonlinear time-history analyses.I have the model of the building in Sap2000 and planning to compare the results. Any idea abou...

Hey there, I am a new user of OpenSees too. I've already started to model a RC building and going to run first a free vibration analysis and then nonlinear time history analyses...I am planning to use opensees navigator instead of writing a tcl script.Did u get any experience in modeling a structure...

Hello,
Is there any recent OpenSees workshop ?