UBC Theses and Dissertations
Pseudo non-linear seismic analysis Hui, Ho Yin Lawrence
A method of evaluating the damage pattern and deflections of planar structures under earthquake excitation is presented. The proposed method is an iterative procedure based on ordinary elastic modal analysis, but it is extended to the inelastic range by using a special technique to take into account the reduction in effective stiffness and the variation in damping. The theoretical development of the method is reviewed in this study and some improvements are also made. These new developments are then incorporated in an existing computer program for the method and tested with different kinds of idealized structures. Test results show good agreement with results obtained from a time-step analysis program DRAIN-2D, provided that the fundamental response period of the structure does not oscillate near the steep descending branch of the smooth spectrum and no extensive yielding occurs in the columns. The proposed method is less expensive than an inelastic time-step analysis and can produce far more superior results than the elastic modal analysis; therefore it is considered as a good alternative to the two conventional types of analysis.
Item Citations and Data