Uncouple Axial Force and Moment in beams
Moderators: silvia, selimgunay, Moderators
Uncouple Axial Force and Moment in beams
Hello everyone,
is it possible to uncouple, for the beams with fiber section, the behaviour between Axial Force and Moment?
In SAP when introduce a Rigid Diaphragm the axial force in beams is 0, but not in OpenSees.
How could I do to obtain the same behaviour for the beams in OpenSees?
I tried to duplicate the nodes and applied the equaldof but it doesn't work. For example
node 121 $X1 $Y1 $Z2
node 1211 $X1 $Y1 $Z2
node 122 $X2 $Y1 $Z2
node 1222 $X2 $Y1 $Z2
equalDOF 121 1211 2 3 4 5 6 (the beam is along the X axis)
equalDOF 122 1222 2 3 4 5 6
element nonlinearBeamColumn 221 1211 1222 $np $BeamXSecTag $IDBeamXTransf;
is it possible to uncouple, for the beams with fiber section, the behaviour between Axial Force and Moment?
In SAP when introduce a Rigid Diaphragm the axial force in beams is 0, but not in OpenSees.
How could I do to obtain the same behaviour for the beams in OpenSees?
I tried to duplicate the nodes and applied the equaldof but it doesn't work. For example
node 121 $X1 $Y1 $Z2
node 1211 $X1 $Y1 $Z2
node 122 $X2 $Y1 $Z2
node 1222 $X2 $Y1 $Z2
equalDOF 121 1211 2 3 4 5 6 (the beam is along the X axis)
equalDOF 122 1222 2 3 4 5 6
element nonlinearBeamColumn 221 1211 1222 $np $BeamXSecTag $IDBeamXTransf;
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Re: Uncouple Axial Force and Moment in beams
The most direct way is to compute the moment-curvature externally and assign it to your section instead of the fiber section
Re: Uncouple Axial Force and Moment in beams
how can I do this?selimgunay wrote: ↑Tue Dec 08, 2020 10:23 amThe most direct way is to compute the moment-curvature externally and assign it to your section instead of the fiber section
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- Posts: 913
- Joined: Mon Sep 09, 2013 8:50 pm
- Location: University of California, Berkeley
Re: Uncouple Axial Force and Moment in beams
You can do it using a zerolength section or 1) model a cantilever column, 2) assign a fiber section to it, 3) apply the axial force that you want to compute the moment-curvature for, 4) do a lateral pushover on your column, 5) record the moment-curvature at the bottom integration point
Re: Uncouple Axial Force and Moment in beams
Thanks.selimgunay wrote: ↑Wed Dec 16, 2020 10:34 amYou can do it using a zerolength section or 1) model a cantilever column, 2) assign a fiber section to it, 3) apply the axial force that you want to compute the moment-curvature for, 4) do a lateral pushover on your column, 5) record the moment-curvature at the bottom integration point