nonlinearBeamColumn/dispBeamColumn
Moderators: silvia, selimgunay, Moderators
nonlinearBeamColumn/dispBeamColumn
Hi everyone, for the pushover analysis of a 3D RC frames what is the difference about nonlinearBeamColumn and dispBeamColumn?
When I plot the curves there are many diffence about the results. Why?
When I plot the curves there are many diffence about the results. Why?
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- Posts: 913
- Joined: Mon Sep 09, 2013 8:50 pm
- Location: University of California, Berkeley
Re: nonlinearBeamColumn/dispBeamColumn
nonlinearBeamColumn is force-based. The other one is displacement based and considers linear curvature distribution along the member length. Therfore, you can model a single member using one nonlinearBeamColumn, however you need several dispBeamColumn elements to be able to capture the correct curvature distribution. Please see this link for a detailed explanation of the differences.
https://opensees.berkeley.edu/wiki/inde ... ed_Element
https://opensees.berkeley.edu/wiki/inde ... ed_Element
Re: nonlinearBeamColumn/dispBeamColumn
This might help too: https://wp.me/pbejzW-A6
The example is a steel member, but the same ideas Selim mentioned hold true for RC.
The example is a steel member, but the same ideas Selim mentioned hold true for RC.
Re: nonlinearBeamColumn/dispBeamColumn
Is there much difference for the results if I use $np 3 instead $np 5 (np=numbers of point integration) for the nonlinearBeamColumn?
I have got a small 3D structure, with columns=4.00 meters and beams=6.00 meters.
When I changed the numbers of the story (2 story to 3 story) the analysis doesn't converge with $np=5 but it is converges with $np=3.
I have got a small 3D structure, with columns=4.00 meters and beams=6.00 meters.
When I changed the numbers of the story (2 story to 3 story) the analysis doesn't converge with $np=5 but it is converges with $np=3.
Re: nonlinearBeamColumn/dispBeamColumn
The force-based elements can be sensitive to the number of integration points, especially for RC structures. You may have localized response somewhere in your model.
Re: nonlinearBeamColumn/dispBeamColumn
If I would like to use $np=5 what could I do to converge the analysis? or it is no necessary
Re: nonlinearBeamColumn/dispBeamColumn
If the results look reasonable to you, then it is not necessary. You can try np=4 as well.
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- Posts: 913
- Joined: Mon Sep 09, 2013 8:50 pm
- Location: University of California, Berkeley
Re: nonlinearBeamColumn/dispBeamColumn
You can compare your analysis results from np=3 and np=5 until the point of nonconvergence. That could give you some idea if np=3 is good enough