Design parameters and performance comparison of viscous dampers and metallic yield dampers

Nonlinear viscous dampers and metallic yield dampers (steel buckling-restrained bracing,et al),are ones of most important ways of structural seismic-resistance design and retrofitting in future.This paper establishes the models and its primary parameters of these two dampers and achieves their equivalent damping ratios from nonlinear characteristic of energy dissipation,and other important parameters in structural design,such as shear ratio of frame,are studied.Then time-history analyses due to strong ground motion are conducted for a single degree of freedom system installed with metallic yield dampers and viscous dampers.The results show that metallic yield damper could change the dynamic characteristic of structural system in a certain extent and remarkably reduce the total input energy and ductility demands.It's performance of energy dissipation is greatly better than that of viscous dampers when their equivalent damping ratios are equal.