USE OF LOAD DEPENDENT RITZ VECTORS IN MODAL PUSHOVER ANALYSIS
The performance of a structural system can be estimated using a non-linear static analysis which has found widespread use in performance based seismic design due to its simplicity in estimating inelastic structural response. Modal Pushover Analysis (MPA) has been suggested to increase the accuracy of Pushover analysis;but it fails in some cases of the irregular structural systems (i.e. stiffer lower stories). The objective of this paper is to present the use of Load Dependent Ritz vectors (LDR) which takes into account the spatial distribution of dynamic force; instead of commonly used eigen-mode shape in the MPA in order to improve the accuracy of calculated response of irregular systems when limited number of modes is to be considered, especially for stiff systems where higher mode effects cannot be ignored. The numerical results have indicated that using LDR vectors, in case of stiffer lower stories, increase the accuracy of force response significantly (because of inclusion of higher mode effects without really computing them). There are also some suggestions about choosing adequate number of required Ritz vectors for vertically regular or irregular structures considered.
Modal Pushover Analysis Ritz vectors LDR Nonlinear Static Analysis Stiffness Irregularity
Hossein Kayhani Mohsen Ghafory-Ashtiany
Islamic Azad University, Science & Research Complex,Tehran, Iran Earthquake Engineering and Structural Department of Science and Research Complex
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）