The OpenSees Community

Dear Vesna, Could you please explain how OpenSees creates the element out of a fiber section? Does it automatically locate the element node at the geometric centroid of the cross-section no matter how the cross-section is defined? I am getting the same results when I define the origin of the local c...

Dear Vesna, To be more clear, can you please explain how OpenSees creates the element? Does it automatically locate the element node at the geometric centroid of the cross-section no matter how the cross-section is defined? It seems to be that way because I am getting the same results when I define ...

Vesna, If the load is applied at the origin of the local coordinate system, the moment capacity should be changing when I change the origin, right? However, no matter which point I choose as a reference point of the cross-section, I obtain the same result. I was hoping that you might find an explana...

Vesna, Thank you for the suggestions. I double-checked my model considering these; however, changing the location of the reference point does not change my results. I figured that the T-section actually works pretty well without applied axial load. I believe the problem is with the location of the a...

Vesna, thanks for your reply. Yes, this is what I did. I have one 2-D wall with fiber T section assigned to it. However, since it didn't seem to be properly working, I removed the flange portion to check whether it works well as a rectangular wall only. Basically, I managed to get perfect result whe...

Hello all, I am modeling a T-shaped wall using fiber section. In order to make sure that the section is properly working, I applied moment-curvature analysis and checked it with my hand calculations and other programs. When I divide the T-shape wall into two to get 2 rectangular walls, I obtain perf...

Hi, I have had a problem for a long time on running pushover analysis for RC shear walls and the results that I have obtained are pretty weird- I was getting a unreasonably small capacity. I played with almost all parameters but it didn't work. The materials I use are hysteretic steel and C02 type c...

hello, i'm running dynamic analyses for rc shear walls and when I increase the intensity of the ground motions, (I start from a scaling factor of 0.1 and increase the factor upto failure), it starts not converging at some intensity levels (for instance, for one wall, it stops converging at a factor ...

Hi, I am conducting dynamic analysis for an 8 story cantilever RC shear wall. The problem is that, I am getting the natural period T=0.49 when I use concrete C02, but T=1.94 when I use concrete C01. I couldn't figure out why that difference is that big and I was wondering which one I should go with....

Hi all,

I am doing pushover analysis on RC shear walls but I guess I have stability problems in taller buildings (like 8 or 12 story ones) because the curve has many fluctuations and peaks. How can I improve the model to make it stable and get a reasonable curve?

Thanks

What does the 'geomTransf PDelta' command do exactly? Does it automatically lead to the consideration of P-delta effects? or are there any other commands on P-delta that could be used for this purpose?

yes I was using steel02. Hysteretic material for steel works, but I though the degradation in concrete itself would also cause the force to drop down after some time. I'm still confused why concrete doesnt affect the backbone in that sense.

I noticed that I'm getting zero stress values after the first 2 time steps till the end of my pushover analysis. I use the following command to get the output: recorder Element -file Data/material.out -time -ele 1 section 1 fiber 80 4 1 stressStrain; at the coordinates (80,4) I have unconfined concr...

Hello, I want to do pushover analysis (displacement based) on a displacement based beam column element, but I cant get any strenght degradation. I'm not using linear transformation (using corotational or Pdelta), and I'm pushing the column to high enough displacements but no matter what I do, the fo...

Thanks Silvia! Now it works after using fix command for that nodes, although I still cannot get what I want. It still does not understand shear behaviour of my spring. Is it a good idea to use zerolenght element to represent shear behaviour? And as a general question, since I have faced that problem...