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Hi Bin,

Thanks for your response.
From your suggestions, I think I have some ideas to try.
I will let you know when I got some results.

Talk to you later. Thanks again.

Ronny Purba

Hi Bin, Thanks for your prompt response. I am not quite sure if I could follow your suggestions correctly. For that reason, I have several follow-up questions trying to understand your thoughts. 1. Are you suggesting to try a "very slow" time-history analysis to replicate a cyclic pushover...

Dear all, Can OpenSees do a "Direct" Displacement Control? What I mean by that is imposing (cyclic) displacement history directly instead of using load factors to reach a certain displacement as in the displacement-control integrator. I studied a two-story frame structure tested previously...

Does anybody ever use Arc-Length Integrator for pushover analysis? It said from my reading that this method is a good integrator for which strength degradation occurred in a structure. I am learning how to use it on OPENSEES but can't completely understand. For example, what's the criteria to let th...

Hi Vesna, Thanks for your help. Now, I understand why I got the same fiber stressStrain results, no matter what ID number I put for the fiber. Using "-xml" you suggested on the previous command: recorder Element -file $dataDir/Fiberstress.out -time -ele 1 section 1 fiber 0 stressStrain; # ...

Hi Vesna, Thanks for reviewing my model. Several things you could try on my cantilever model: 1. Play with the level of axial forces. I provide two options in section 6.1 of my input as follows: #set P [expr 201.6*$kip]; # axial load magnitude set P [expr 0.0*$kip]; # axial load magnitude so you can...

Sorry for the repeated short posting... Inadvertently, I changed the level of axial force, then interestingly I start to see realistic results on stressStrain Again at 4% drift, the result: 51.828 -50 -0.0269694 Realistic but still wonder, why it is the case...why the stressStrain is nothing (~close...

I just found in the wiki manual, using fiber ID to request for stressStrain can be used as well. So, I changed the recorder commands to: recorder Element -file $dataDir/FiberStress.out -time -ele 1 section 1 fiber 0 stressStrain; # top fiber stress strain I remember somewhere in the manual that say ...

Hi Vesna, That recorder command is exactly what I used and it gave me nothing except "-time" records. I believe "0.10 0.10" referring to local y and z coordinates, right? It worked for other beam-column elements. Here is the command I used comparable to yours: recorder Element -f...

Dear all, I tried to investigate zero-length-section (ZLS) element with fiber section for my degradation model (per Vesna's recommendation). I thought before I try it on my complete SPSW model, I better try it on a simple model. So, I modeled a simple 2 m (~79 in) cantilever of W18x65 steel. The mod...

Thanks Vesna for your response. I am working on zero-length-section right now... will let you know if i got something different. Any idea why I still observe dramatic drop on my pushover curve even for the case of zero-length element? Other than many non-linearity assigned to the model, as you menti...

I tried using zero-length element. Here, hysteretic material is now in moment-rotation relationship. In a quick look, the result is not much different with the previous one. Figure in this link (http://www.buffalo.edu/~rpurba/OpenSeesPushoverResultsZLE.jpg) shows pushover analysis results with zero-...

Thanks vesna. I'll try to learn zeroLengthSection Element and see if it gives a more reasonable result. I agree with you that my model has many nonlinear elements that do not reach yield or degradation at the same time. However, I think, the base shear should not dramatically bounce back to a higher...

Dear all, I tried to model steel plate shear walls (SPSW) in OpenSees. I am expecting the model can simulate strength degradation in SPSW. However up to this point, I didn't get satisfactory results, meaning my pushover results was somewhat unrealistic/weird. Let me explain my SPSW model I used in O...