Performance of a zero stiffness isolator under shock excitations

Abstract

The characteristic of a zero stiffness isolator is given first and the stiffness difference between the zero stiffness isolator and a linear one is discussed. Three different types of displacement shock excitations are applied to the base of the zero stiffness isolator and the linear isolator. Three indices are defined to analyze the characteristics and evaluate the performance of the nonlinear isolator. The absolute displacement shock responses in time domain and the maximum absolute displacement ratio for the undamped linear and nonlinear systems are presented for different shock severity parameters. The performance of the damped nonlinear isolator is studied and compared with that of the linear isolator. Results show that the performances of the nonlinear isolator are related to the parameters of the nonlinear isolator and the type of the shock excitation. It is beneficial to introduce a zero stiffness isolator for shock excitations, but the performance is limited by certain conditions. Some useful conclusions which can be used to design this kind of isolator for considering shock isolation are given.