Competing failure modeling for degradation-shock dependence systems with shock toughness

Failure of complex systems is usually the result of dependent competing between degradation failure and sudden failure caused by some random shocks. In this paper, a degradation-shock dependent competing failure model and reliability evaluation method based on nonlinear Wiener process are proposed for some systems with shock toughness. The m-δ shock model is used to consider the ability of the system to resist the shock load, that is, only when the random shock frequency is higher than a certain level, a sudden failure will occur, and in other cases, only the degradation process will be affected. On this basis, the nonlinear Wiener process model is modified to consider the effect of random shock on the degradation of the system in both the degradation increment and the degradation rate. Finally, a space memory unit case is used to verify the proposed method, and the parameter sensitivity analysis is carried out.