Pushover Analysis On Steel Frameworks And Modal Pushover Procedure Research

Nonlinear static procedure (NSP) has attracted the attention of more and more researchers for its merits of practicality. It has become one of checking computations tools for nonlinear distortion. Pushover is used to assess the seismic performance of a nonlinear static analysis method. It combines the inelastic static analysis with the seismic response spectrum and avoids the time-costing process in nonlinear dynamic analysis. It's been proved by practical engineering abroad to have good accuracy and simplicity. It can save both financial cost and computational time. The study on this method has both the theoretic worthy and engineering worthy.Design procedure and analysis method of structure in earthquake are firstly introduced in this thesis. Then the basic theory, origin and the approach of the NSP was presented, displacement-based seismic design including origin, basic principle and the selection of designing displacement are followed. Then several pushover analysises are presented. The horizontal loading model is very important to the static pushover analysis. The option of the horizontal load model will influence the result of static Pushover analysis directly. Through performing the static pushover analysis to a frame structures, the author discussed four horizontal loading models.At last, the paper focuses on a Modal Pushover Analysis Procedure presented by Chopra from UC Berkley, points out the characters of MPA in elastic and inelastic analysis comparing with the time history analysi. The results of examples demonstrate that the improved modal analysis can consider the influences of high modes of structure in inelastic stage effectively.