Inelastic Seismic Responses of a Test Structure with Supplemental Viscous Dampers

Shaking table tests are conducted to investigate the inelastic seismic responses of a three-story steel model structure designed with nonlinear viscous dampers. It is intended to identify the energy dissipation by the hysteresis of the dampers and the plasticization of the structural components when the structure is excited into the inelastic range. In order to evaluate the efficiency of the added dampers in reducing the seismic responses of the test structure, test results from the test structure with dampers are compared with the analytical results from the test structure without viscous dampers. The equivalent linear analysis specified in NEHRP2000(FEMA368) [1,2] is evaluated for its prediction accuracy for the maximum seismic responses of the test structure subjected to various earthquake ground motions. Suggestions are drawn for designing the damping coefficient C and damping exponent αof the viscous dampers.