Dear vesna and all other proffesion openseeser!
I've modeled a 1-bay 1-story steel moment frame and subjected it to an earthquake record. I want to record plastic rotation for the beam.As you know, the plastic rotation should be evaluated using the curvature. I have some questions:
1. what kind of element should I use for the beam? nonlinearbeamcolumn or beamwithhinges?
2. how can I record curvature?
3. how can I compute Lp, to use it in the calculation of plastic rotation?
I hope anyone would explain me the case
1. if material is steel you can use either of the two, but if the material is concrete I prefer nonlinear beam-column element
2. record deformation of a section to get the curvature
3. depending on the material there are empirical formulas that you can use to calculate Lp
Dear Vesna
thanks for your answer, but what kind of deformation of a section should i record for curvature? (in a 2 dimention problem: 1, 2 or 3?)
and,
are the following formulas correct for the calculation of the plastic rotation using the curvature?
Lp = (L/2)*(1 - final_moment/yeilding_moment)
Plastic Rotation = Lp * (final_curveture - yeilding_curveture)
record your section deformation using -xml (instead of -file) and you will get information about each of the columns in the recorded file. this way you will know which column corresponds to curvature.
