Reliability-based Robust Design of High-speed EMU Axle-box Spring Based on NSGA-II

In order to improve the reliability and robustness of the parts of high-speed vehicles,based on the reliability optimization design theory and the robust design method,the reliability sensitivity was integrated into reliability-based robust design model of the axle-box spring,which was described as a multi-objective optimization problem.The paper calculated the numerical example for the Pareto solutions by using the NSGA-Ⅱ genetic algorithm,and selected the best solution to the optimal design according to the experience and the importance of the objective function.The analysis results showed that the mass of spring was reduced and the reliability of spring was improved after the reliability-based robust optimization design for axle-box spring.Further,the sensitivity value of each basic design parameters relative to the reliability of spring decreased significantly while the reliability and robustness increased,verifying the practicability and effectiveness of the design method.