ABSTRACT
It is reviewed the study on reduction factor which allow the estimation of lateral strength required to control the level of inelastic deformation during strong earthquake ground motion. Based on modified Takeda hysteretic model, including the hysteretic effects of post-yield stiffness, stiffness degradation and strength deterioration, the reasonable hysteretic parameters have been developed, and the reasonable relations between the hysteretic parameters and ductility coefficient have been derived. Based on the equivalent ductility coefficient from Park-Ang dual-damage criterion, strength reduction factor spectra respect to different damage indices have been calculated using the regression formulas suggested by L. H. Lee. The spectra can satisfy the different seismic design level. The results of comparison study have shown that the strength deterioration and the cumulative damage of the structure have a remarkable effect on the strength reduction factor and the neglect of the two factors above mentioned might lead to an unconservative design result.
