Analytical and Experimental Study of Toggle-Brace-Damper Systems

The toggle-brace mechanism has been recognized as an effective installation configuration of viscous dampers to a stiff structural system. In this paper, a toggle-brace-damper configuration with dampers directly installed to the beam-column joints is presented. To facilitate practical applications, a procedure for determining the relationship between the displacement magnification factor and the geometry of the toggle-brace mechanism is established. Shaking table tests are conducted to investigate the seismic responses of a three-story steel model structure with and without linear viscous dampers. The installation configurations of the dampers include the toggle-brace-damper and the diagonal-brace-damper systems. The test results show that the toggle-brace system is more efficient in enhancing the seismic response control on a stiff structure. However, due to the fact that the gaps existing in the hinge connections of the toggle-brace-damper system may affect the contribution of damping ratio to the structure, special care must be taken when installing toggle-brace-damper systems in practical applications.