Development and seismic performance improvement of hybrid damping self-centering braced frame

Abstract

A novel hybrid damping self-centering brace (HD-SCB) with friction dampers and viscoelastic dampers is proposed in this paper. The ratio of the frictional force and viscous force in the HD-SCB system can be easily changed. Through a solid finite element model, the HD-SCB is found to have a controllable velocity-based energy dissipation capacity. A series of the HD-SCB frames (HD-SCBFs) are designed with a presented design method, which considers the energy dissipation equivalent and the damping force equivalent. 2 groups of the scaled ground motions with or without a velocity pulse are selected, and the pulse characteristics are identified by calculating the pulse indicator of each record. A novel higher mode analysis method is proposed to observe the participation of the higher mode. Through comprehensive analyses on the HD-SCBFs, it can be found that adding viscoelastic dampers can significantly reduce the displacement response of the higher floor because the higher mode effect is weakened. The ratio of the frictional damping force to the viscous damping force of the HD-SCB is suggested to be 0.25–0.50. In this case, acceleration response can be reduced by 25% without amplifying the base shear.