Theoretical analysis and application research on local toggle energy dissipation device

Abstract

The toggle-brace-damper system (TBDS) can obviously improve the energy dissipation efficiency of a damper by amplifying its deformation. The small deformation solution is widely used to characterize the amplification capacity of the TBDS. However, the parameters of the small deformation solution are not mutually independent. Furthermore, as the small deformation solution is a constant, it cannot comprehensively characterize the mechanism of the TBDS. These drawbacks hinder a more in-depth study of the TBDS mechanism. In addition, the existing TBDS requires a large building space, which adversely affects the layouts of doors and windows. In view of the problems above, a space-saving local toggle-brace-damper system (LTBDS), as an extended form of the TBDS, is proposed. The displacement amplification factor considering the large deformation effect is derived. The variation law of this amplification factor with the lateral displacement is clarified. The local toggle energy dissipation device (LTEDD), which consists of two identical and symmetrically arranged LTBDSs, is recommended to overcome the LTBDS’ amplification capacity asymmetry. The effects of the geometric parameters on the amplification capacity of the LTEDD are clarified. A geometric optimization method to improve the amplification capacity of the LTEDD is proposed based on the estimation of the maximum lateral displacement of the LTEDD under earthquakes. To estimate the maximum lateral displacement of the LTEDD and calculate the additional damping ratio contributed by the LTEDD damping system, the storey drift utilization ratio is proposed, and the calculation method is derived and verified. Finally, the case analysis verifies the feasibility of the LTEDD and the effectiveness of the optimization method.