Nonlinear Behavior of Quasi-zero Stiffness Nonlinear Torsional Vibration Isolator

Abstract

Abstract This paper researches the nonlinear behavior of a nonlinear torsional vibration isolator (NTVI) which is composed of flexible rod element and electromagnetic element. And the NTVI has a quasi-zero stiffness (QZS) characteristic. Firstly, a statics model of the QZS-NTVI is established and the effects of geometric parameters on the QZS behavior and restoring torque are described. Then, the statics model approximated by the Taylor series is incorporated into the dynamic model of QZS-NTVI. The stability of the harmonic solution is analyzed and the amplitude-frequency response and the torque transmissibility curves under different geometric parameters are derived according to the harmonic balance method. Furthermore, numerical analysis effort is performed to study the nonlinear behavior of QZS-NTVI. The results show that the QZS-NTVI exhibits super-harmonic and sub-harmonic resonances and undergoes the periodic and chaotic motions alternatively with the change in the excitation amplitude and the angular frequency. Finally, both the simulation and experimental efforts are performed to validate the statics model of the flexible rod and to study the vibration isolation performance and nonlinear behavior of QZS-NTVI. The results demonstrate that the vibration isolation performance of QZS-NTVI notably outperforms the linear system, as well as nonlinear behavior with frequency jump.