非线性阻尼非线性刚度隔振系统随机动力学特性研究

Abstract

Both nonlinear damping and nonlinear stiffness were introduced in vibration isolation systems under random excitations to improve the isolation performance. The nonlinear damping and nonlinear stiffness were realized through the geometric arrangement of the horizontal springs and horizontal dampers. The performance of the nonlinear vibration isolator under random excitation was evaluated with the equivalent FokkerPlanckKolmogorov (FPK) equation transformed by the nonlinear stochastic vibration equation. The effects of the nonlinearity introduced in stiffness and damping on the transmissibility and its probability were studied. It is found that, for high levels of random excitations, the damping nonlinearity brings larger reduction of the random vibration response, and the gap between the linear and the nonlinear dampings is enlarged; however, for low levels of random excitations, the nonlinear damping has less efficacy than the linear damping.