考虑牙间均载的拉杆螺纹连接多目标优化

摘要

为提高机架螺纹连接寿命,运用弹塑性接触有限元方法对拉杆连接螺纹进行强度分析,结合参数化建模,建立考虑牙间均载和应力峰值的多目标优化模型,采用径向基函数(RBF)神经网络方法和带精英策略的非支配排序遗传算法(NSGA-Ⅱ)求解.结果表明:牙侧角约为15°时,牙间轴向载荷分布不均匀率减小13.6%,等效应力峰值减小6.9%,第一主应力峰值减小11.5%.%For improving the serving life of the threaded connection,an elastic-plastic contact finite element method was used for analyzing the stress distribution of the connecting threads.After that, the parametric modeling technique was used for establishing the multi-objective optimization model where the load distribution uniform and the stress peak values were considered.This model was then solved by the radial basis function (RBF)neural network method and the elitist non-dominated sorting GA (NSGA-Ⅱ).The numerical results indicate that compare with the original design,the non-uni-form rates of load distribution between the teeth in the optimized design are reduced by 13.6%,and the maximum of equivalent stresses is dropped by 6.9%,and the peak values of the first principal stress are cut down by 11 .5%.