The Influence of the Geometric Nonlinear Stiffness and Damping in the Quasi-Zero Stiffness Isolator Subjected to Shock Vibration with Varied Shock Period

Abstract A vibration isolator is a mechanical device for isolating an excessive force that transmitted from the vibrational source to the main structure. The isolator can benefit to the use of nonlinear damping and stiffness components. This nonlinear characteristic can adapt to the amplitude of motion. Therefore, this study presented an investigation for the influence of geometric nonlinear damping and stiffness on the performance of the isolator with HSLDS or QZS characteristics. The isolator was subjected to a base displacement with the half sine profile and a variation of the shock period. Furthermore, a numerical simulation was employed in this study using a novel Runge-Kutta-Verner 9(8) algorithm. The algorithm was implemented to solve the nonlinear equation of motion of the isolator in an approximate form of the seventh-degree polynomials. The numerical results indicated that the isolator had outperformed the linear isolator under a condition of light shock excitation. Conversely, the isolator’s performance was found to be deficient under strong shock excitation.