Moment-Rotation Curve

[Maple]

Dear fmk and all,

I don't know if I can get Moment-Rotation diagrams directly in OS,
what I can get is the Moment-Curvature dagrams.

I want to get moment rotation diagrams of column at bottom and top locations,
How should I do?

[fmk]

record the section forces and deformations and then plot them using the record command appropriate for you element type and section type.

[Maple]

Thanks fmk,
I can record the section deformations, but "the deformation" refers to "curvature",
I want to get is "rotation", I don't know whether should I take some measures to acquire "rotation" from the recorded "curvature" ?

[fmk]

depends on how you are modeling the structure .. if using zerolength hinges the forces and deformations are what you want, if using beam column elements (which i suspect you are given your reference to curvature) then no you can't get from OpenSees directly .. you have some post-processing to do .. the following paper for example presents relations between moment-rotation, moment-curcvature, integration rule and hinge length.

http://earthquakespectra.org/doi/pdf/10.1193/1.4000136

you cannot obtain the moment-rotation directly

[rajaeian]

Hi all.
I want to convert "Kishi and Chen'' power model of semi rigid connection which is obtained Rki(initial connection stiffness), Mu(ultimate moment capacity) and n(shape parameter) to something useful for modeling semi-rigid connection in OS.
I need Fy,E and B to modify material steel01.
regards.

[davidzarei]

Hi Rajaein
I want to do the same, please send some instructions if you have done it successfully.
Regards.