考虑牙间均载的拉杆螺纹连接多目标优化

Multi-objective Optimization of Threaded Connection on Tension Rods for a Uniform Load Distribution between Teeth

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-uniform 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%.