STUDY ON THE SEISMIC BEHAVIOR OF GRADED YIELDING METAL DAMPERS

In this paper a new type of graded yielding metal damper composed of two annular metal dampers with different sizes was proposed. The seismic performance of the new damper was studied by cyclic loading tests. The failure mechanism and energy-dissipation mechanism of the damper were revealed. The hysteretic energy-dissipation behavior, strength and stiffness degradation, and fatigue resistance of the damper were analyzed. The experimental results show that the damper not only achieves graded yielding function effectively, but also possesses large deformation capability, full hysteretic loops and excellent anti-fatigue performance. The modification coefficient of the initial stiffness of the damper was obtained by parametric finite element analysis and regression analysis. The formulas to determine the performance points in the load-deformation skeleton curve were proposed. The calculated skeleton curves agree well with the experimental results. Accordingly, the geometry of the damper can be determined by the performance requirement. The research results of this study can provide technical support for the engineering application of the new metal damper.