09-25-2010, 10:19 PM
Since you use Sap2000 or ETABS, reading FEMA356 and its guidelines on static nonlinear analysis would help. But it is up to you to decide how to model the plastic hinges you expect will be formed (and where..). My advice is: run an elastic analysis using the design loads of the structure and see which is the closest to yield: bending moment or shear force. Then you will form the hinge law on the programm accordingly (M3, or V2 for beams, usually PMM for columns). Either way it is explained well enough on FEMA 356.
PS I don't really like pushover analysis when it comes to 3d models with irregular shape and altered stiffness on each floor as higher eigenmodes have significant contribution to mass participation, while the load pattern of the analysis does not correspond to them. If this happens, FEMA predicts measures, albeit, in my opinion, questionable.
Good luck,
Avge
PS I don't really like pushover analysis when it comes to 3d models with irregular shape and altered stiffness on each floor as higher eigenmodes have significant contribution to mass participation, while the load pattern of the analysis does not correspond to them. If this happens, FEMA predicts measures, albeit, in my opinion, questionable.
Good luck,
Avge
Sometimes, less is more