The mechanical model of a new spring locking mechanism was established. The optimum spring parameters of the locking mechanism which meet the design requirements were provided by optimization. Using the finite element method, numerical simulation of working process of the locking mechanism was carried out. The rationality of optimization result was verified by simulation results of numerical simulation.

In order to solve reliability-based optimization design of composite transmission shaft, the parametric finite element model of composite transmission shaft was built by secondary development of ABAQUS. The reliability analysis of composite transmission shaft was carried out with the first order reliability method (FORM). Using python language, the finite element program and reliability analysis program are combined. The reliability-based optimization model of composite transmission shaft was obtained. The feasibility and effectiveness of the optimization model was verified by the results of an example application.