The OpenSees Community

Section deformation (axial and curvature) can be obtained with the Element Deformation recorder: recorder Element -file FileDeformation.out -ele 1 section 1 deformation End section forces can be obtained with the Element Forces recorder: recorder Element -file FileForces.out -ele 1 globalForce The t...

1) The initial stiffness of the element is supposed to be controlled by the elastic element. Maybe you should look at the EI you are using to define the elastic element. 2) It wasn't me that posted this example so I am not the right person to talk about it. I will let others explain it because they ...

Regarding the concentrated plasticity model: 1) n=1.5 is way to small to provide you accurate results. The spring must be rigid-plastic. This means that in the elastic region the spring should have negligible deformation. Ibarra and Krawinkler (2005) and Zareian and Medina (2010) have suggested n=10...

You can, but I believe it is better to start by posting your code here so that the problems and solutions are shared with everyone.

Filipe Ribeiro
f.ribeiro@fct.unl.pt

1) Since you defined well the model parameters for using with the BeamWithHinges (don't forget you are defining a moment-curvature relationship), there is no apparent reason for it. .. please post your code so that I can take a look at it. 2) I guess that 0.004*L does not have any physical meaning s...

You can record the moment at the element ends, where the plastic hinges will form. The rotation is obtained by integrating the curvature along a defined length so there is no rotation associated with the hinge section. What you can do is to record the curvature at your hinge section (using the eleme...

The paper by Scott and Ryan (2013) only addresses the case of elasto-plastic material with hardening. In the case you have a softening region, the second paper proposes a calibration procedure for force-based beam column elements. Hope it helps.

The Bilin material and the parameters proposed by Lignos and Krawinkler (2011) were thought to define a Moment-Rotation relationship. Thus, it is appropriate to be assigned to concentrated plasticity elements. However, if you want to implement it in a distributed plasticity element, you should be aw...

With the code above I'm afraid you're not reaching the yield moment. Thus you are obtaining a linear elastic response and not the desired hysteretic curve. By symply increasing the "ratio" variable you would fix that. However, I am not sure what's the purpose of this variable as is. In the...

There was a minor bug in the update of the unloading stiffness due to deterioration. The code with revision 5531 contains the latest bug fix so that stiffness deterioration also works for the case when the Bilin material is used in zero-length springs with the optional n-factor. Please use this late...

The changes made in the last commit were mainly related to the update of model parameters due to cyclic deterioration. Additionally, other minor bugs, namely in the post-capping stiffness, were corrected. However, from the validation examples we used, not large differences are expected. Can you post...

Only the solving algorithm.

Filipe Ribeiro

We have modified the example by changing a few dynamic analysis parameters and, from the runs we made, convergence is now attained without trouble.

Filipe Ribeiro

Sorry for the big text, hope you don't get :? I have another possible reason to explain this situation: When a timeSeries and a uniformExcitation is defined the first point corresponds to the time 0.0 isn't it ?? When I start the second dynamic analysis the time is, e.g. 70s, so at that time there i...

I did what you said and I realized that there is no problem with the grav loads. I found the problem is the uniformExcitation itself. I defined the uniform excitation using timeSeries in order to get the absolute accel. Then I recorded the accel of the base nodes (whose accel must be the same of the...