Seismic analysis of a frame structure equipped with displacement-amplified torsional dampers

Abstract

The angular displacement of the beam-column joints of the frame structure is small under earthquake action, and the seismic mitigation effect of ordinary dampers placed at the joints is not obvious. The displacement-amplified torsional damper (DATD) is one that can be directly installed at the joint and has a displacement-amplifying function. Finite element numerical simulation on the mechanical properties of DATD was carried out in this paper. The theoretical mechanical model of DATD was derived, and the trilinear mechanical model and the modified Bouc-Wen model were used to describe the mechanical characteristics of DATD, respectively. Numerical simulation and theoretical analysis results agreed well with the experimental results. Then, the ETABS software was adopted to analyze and compare the dynamic responses of ordinary frame and frame equipped with DATAs under frequent and rare earthquakes. Results showed that compared with the uncontrolled structure, the inter-story angular displacement, top-story displacement and internal force at the frame joints of the controlled structure equipped with DATDs remarkably decrease, and the effect of energy dissipating and vibration control is obvious. DATD significantly delays the structural damage at the joints while dissipating the input earthquake energy and reducing the structure’s dynamic responses.