Reliability sensitivity analysis of a vibration transfer path system based on stiffness degeneration

A structural system must undergo stiffness degradation during the vibration process. By introducing the stiffness cumulative damage theory into the vibration differential equation, combined with the stochastic finite element method and the reliability theory, a mathematical model of the reliability and reliability sensitivity of the vibration transfer path system with random parameters considering stiffness degradation was obtained. The reliability and the reliability sensitivity to each random parameter of a tool holder system at the random parameter mean with the excitation frequency and time were obtained. The results show that the stiffness degradation caused the reliability and reliability sensitivity to random parameters to shift with time; the reliability sensitivity peak fluctuates with time; the peak value in the frequency domain at the initial time is not necessarily the maximum value in the time domain. The accuracy of the method was further proved by the Monte Carlo method. System stability can be enhanced by optimizing sensitive parameters; the resonance failure caused by the change of the resonance region with time can be effectively prevented. © 2020, Editorial Office of Journal of Vibration and Shock. All right reserved.