Study On Elastic-plastic Earthquake Response Spectrum Of Construction Structure

Response spectrum theory is one of the basic theory of performance-based seismic design methods. Elastic response spectrum theory, which is widely used in aseismic design around the word, has become more and more maturer. However, most structures under the conditions of higher intensity in the region, will be the inevitable entry into non-flexible working conditions, therefore elastic response spectrum method based on the design of engineering structures, the accuracy of their calculations as well as the structures of their own safety performance are being to the question. It is significant for improving the seismic analysis level, developing the performance-based seismic design and understanding the relation between the ground motion characteristics and the structure dynamic characteristics to study the inelastic response spectra. Therefore, the research on inelastic response spectra becomes indispensable as the development of the PBSD and capacity spectrum method in recent years.According to the current aseismic design codes theory, a study has been carried out on the following content:(1) Using double broken line elastic-plastic model, the post-yield stiffness coefficient is taken to be 0, 0.02, 0.06, 0.10 , while damping ratio to be 5%, and the ductility factor of 2 ~ 5 to analyse single degree system's elastic-plastic seismic response in different site categories and caused by far-field vibration wave and near space vibration wave, then establish constant ductility of elastic-plastic acceleration and displacement spectra, and analyse the differences between them.(2) Elastic-plastic acceleration spectrum and displacement spectra have been established with the ductility between 2~5 through the nonlinear time history analysis of a single degree of freedom system.Therefore,we can put it as exact solution to evaluate the accuracy of the equivalent linearization methods.This paper evaluates six equivalent linearization methods, i.e. the secant stiffness method (R&H), the method based on the average stiffness and energy(ASE), the method based on the average stiffness and damping coefficient(ASD), the empirical method by Hwang(HWANG), the empirical method by Iwan(IWAN), the method by Kowalsky(KOWALSKY). (3) According to the elastic response spectrum used in the Code for Seismic Design of Buildings, we can compare the elastic-plastic response spectrum established by the the equivalent linearization methods and the elastic-plastic response spectrum based on R-μ-T model such as models respectively by Vidic, Newmark and Hall, Krawinkler and Nassar , Fan Li-chu .