Energy analysis of a nonlinear gas-spring dynamic vibration absorber subjected to seismic excitations

Abstract

Nonlinear control methods and devices have been widely used in seismic vibration reduction of engineering structures. A nonlinear gas-spring dynamic vibration absorber (NGSDVA) has been recently proposed by the authors and demonstrates a wideband vibration suppression capability across various excitation amplitudes. In this study, an energy analysis method for a multi-story structure with NGSDVA attached under seismic excitation is proposed through experimental and numerical simulation analysis. The energy distribution of the controlled structure and the energy transmission process between the main structure and the damping system are analyzed. It is found that the intermodal energy transfer phenomenon occurs in the five-story steel frame structure during the energy transmission process, while the first-order modal energy is converted to high-order modal energy simultaneously. A series of energy-based parametric studies are further conducted, and the consistency of the parameter influence rules under four different seismic waves is proved, indicating the advantages of energy evaluation indicators for optimizing the design of this nonlinear damper with amplitude-frequency characteristics.