考虑焊点不确定性的车身点焊结构疲劳寿命优化

基于区间优化的方法，构建了考虑焊点不确定性的TS、MTS两种点焊结构的疲劳寿命不确定性优化模型。采用修正的Manson-Coffin公式作为点焊结构的疲劳寿命计算公式，同时考虑工艺中焊枪落点的不确定性，将焊点的位置坐标作为区间变量，通过对焊点坐标进行区间优化,获得结构疲劳寿命最大时的焊点坐标。给出了相应标准焊接结构试样疲劳寿命的上下界,为工程实际中点焊结构的疲劳寿命极限的分析及最优设计提供了计算工具。

Fatigue Life Optimization for Spot-Welded Structures of Vehicle Body Considering Uncertainty of Welding Spots

Fatigue life interval  optimization  analysis model with two types of welded structures:tensile-shear(TS) and modified  tensile  shear(MTS)  spot welded joints would be  constructed  based  on  interval optimization method,considering uncertainty of  the  welding spots.Using the modified Manson-Coffin formula  as  fatigue  life  calculation method of spot welded structures,taking  consideration  of  the characteristics that the uncertainty of welding torch placement during the process,the positions of the welding spots  were treated as interval variables.By interval optimization of welding spot coordinates,maximum fatigue life and best welding spot coordinates of the two types of welded structures could be obtained.Further more,corresponding upper and lower fatigue life bounds of the standard sample  welded structures were also demonstrated.A computing tool with function of analysis and optimal design of the fatigue life was provided,which could be applied on spot welded structures in engineering practices.