Study on Dynamic Behavior and Vibration Reduction Performance of BPNES

Abstract

Nonlinear energy sink (NES) can transfer energy efficiently and unidirectionally through target energy transfer (TET). However, its performance is sensitive to the excitation intensity. When the excitation is lower than the trigger threshold, the performance of NES will be greatly reduced. When the excitation exceeds the trigger threshold, its performance will decrease with the increase of the excitation. At the same time, strong excitation may lead to high branch response of the linear oscillator (LO) under harmonic excitation, which will make the vibration worse. In view of those, NES with negative stiffness is proposed to improve the vibration reduction performance under low disturbance. Meanwhile, 2DOF parallel nonlinear energy sink (PNES) is used to ensure the performance under strong excitation. Two important indexes of bistable NES (BNES), the threshold of the transition from intra-well periodic vibration to inter-well chaotic vibration, and the strongly modulated response (SMR) trigger threshold of BNES, are analyzed in this paper. The parameters of bistable parallel nonlinear energy sink (BPNES) are optimized, and the vibration performance of BPNES and cubic stiffness NES (CNES) is compared. The analysis results show that, the performance of BPNES is better than that of CNES under both impulse and harmonic excitation.