转子系统配合面过盈联接的可靠性灵敏度分析

Sensitivity Analysis of Reliability of Rotor System Matching Surface with Interference Fit

基于摄动原理,推导出了转子系统在过盈联接配合面发生打滑及塑性变形两种失效模式下的随机变量均值、方差、协方差及随机变量间相关系数的可靠性灵敏度公式;结合电主轴实例,讨论了电主轴的主轴与其内装转子过盈配合设计有关的各随机变量的均值、方差、协方差及随机变量相关系数对结构可靠性的影响;对影响系统可靠度的尺寸参数的均值的重要性进行了排序,通过排序得到了实际过盈量的均值是影响可靠度的最敏感参数的结论。应用遗传算法对配合面实际过盈量的均值进行一维无约束优化,优化后系统可靠度得到了提高。

Based on the perturbation theory,the reliability sensitivity formula about the mean value,variance,covariance of rotor system′s random variables and the correlation coefficients between rotor system′s random variables under two failure modes,which are skidding on interference fit mating surface and plastic deformation,are deduced.By using an example,the influence of the mean value,variance,covariance of random variables and the correlation coefficients between random variables,which are related to the design of interference fit between the spindle of electric spindle and its inner rotor,on structural reliability is discussed,and through sorting the importance of mean value of the size parameters affecting the reliability of the system,it is concluded that the mean value of the actual interference amount is the most sensitive parameter that affects the reliability.The genetic algorithm is applied to the one-dimensional unconstrained optimization of the mean value of the actual interference amount of the matching surface,and the reliability of the system is improved after the parameter optimization.