Abstract
This paper presents a performance based design method which is able to estimate the energies of the structures with bilinear typed viscous dampers and bilinear elasto-plastic dampers by means of separated variables; that is, an equivalent energy spectrum for given ground motions is expressed in terms of the product of an elastic spectrum _pS_<v,40>(TE) and empirical formulas of viscous damping ratio h_o, bilinear relief velocity ratio (=maximum response velocity/relief velocity) μ_v, second viscous coefficient ratio P_v, ductility factor μ_d, and bilinear stiffness factor P_d The desigh diagrams are also proposed by making use of the empirical formulas. Thus, design parameters of dampers can be easily evaluated, if a designer specifies the values of h_o,μ_v,p_v,μ_d and p_d for the design spectrum of a ground motion. The paper shows also good agreements between the estimated design values and the results computed by non linear time history analysis.
