A global sensitivity analysis method for complex mechanisms of aircraft affected by multiple progressive damage

Failure of an aircraft Drag Chute Lock Mechanism (DCLM) can prevent the drag chute from being thrown properly, which may threaten the safety of aircraft and crew. The DCLM is affected by Multiple Progressive Damage (MPD) factors during operation, and its global sensitivity analysis introduces many parameters that substantially increase the computational cost. This paper proposes a global sensitivity analysis method based on partial derivatives to solve the above problems, which reduces the dimensionality of the parameters to decrease the computational cost and improve the efficiency of global sensitivity analysis. Based on the operating principle of DCLM, it is analyzed for MPD factors, including wear, impact and creep. A reliability model considering MPD factors is developed for the DCLM, which is analyzed using a global sensitivity calculation method that is based on partial derivatives, and optimization suggestions for improving reliability are given for important input parameters. The results of the numerical study show that the proposed partial-derivative-based global sensitivity analysis method improves the efficiency of sensitivity analysis under consideration of the MPD and increases the reliability of the mechanism through parameter optimization.