A reliability analysis method for evaluating performance degradation considering the coupling of multiple progressive damage factors and multiple stochastic factors

The manufacturing and use of aircraft lock mechanisms are characterized by coupling multiple stochastic factors and multiple progressive damage factors that seriously affect the reliability of the mechanism. For a certain type of aircraft drag chute lock mechanism, a reliability degradation analysis method considering the coupling of multiple stochastic factors and multiple progressive damage factors is proposed. Based on the working principle of the drag parachute lock mechanism, the effects of multiple progressive damage factors on the motion accuracy of the mechanism are analyzed by considering the wear and tear over time, the deformation due to impact and the creep of the steel cables. The influence of multiple stochastic factors on the function of the mechanism is investigated, and the multiple stochastic factors include manufacturing and processing errors, changes in material properties, and changes in environmental stresses. A reliability degradation model and sensitivity analysis method based on multiple progressive damage factors under multiple stochastic factors are proposed. The results show that the proposed method can provide guidance for the design, manufacture and utilization of drag chute lock mechanisms as well as the reliability analysis of complex mechanical mechanisms in other aerospace products.