不同场地类别减震性能曲线研究

Establishing damping performance curves according to different site types seismic waves solves the problem of differences in seismic wave damping performance curves, it is of great significance to simplified design and analysis of shock absorbing structures-Here, under simple harmonic excitation of single mass point system, based on analytical expressions of the displacement damping rate η_d and acceleration damping rate η_a, the site classification for a large number of seismic waves was performed according to their characteristic periods, and time-history analyses for all different site types seismic waves were done to obtain damping performance curves applicable for various site types seismic waves. Considering effects of site characteristic period on damping performance curve, fitting formulas for calculating displacement and acceleration damping rates under elastic time-histories were determined. Then, damping performance curves considering nonlinear states of structure were established. Curves showed that although increasing damping rate can reduce the plasticity rate of structure, the reduction effect is limited, and the larger the plasticity rate, the less obvious the damping effect of increasing damping rate; the study can expand the application range of damping performance curves and provide an important basis for performance-based design of shock absorbing structures.