钢板点焊翘曲缺陷对平均应力强度因子的影响

Effects of Warping Defects of Steel Plate Resistance Spot Welding on Average Stress Intensity Factor

车身焊接易造成翘曲缺陷,显著影响其疲劳寿命。针对翘曲缺陷对平均应力强度因子的影响,基于力学理论和有限元法,将焊点模型模块化,对比分析仿真得出的合格焊点平均应力强度因子ΔK_(qua)与翘曲缺陷焊点平均应力强度因子ΔK_(def)。通过寻找影响因素及影响规律,提出翘曲因子C的概念并通过仿真验证其适用性。仿真分析与理论推导得出的平均应力强度因子间的平均误差小于6%。试验结果表明,经翘曲因子修正的翘曲缺陷焊点ΔK_(def)的平均准确率为84.6%。

Welding of car body might easily cause warping defects,which significantly affected the fatigue life.Aiming at influences of warping defects on the average stress intensity factor,solder joint model was modularized based on mechanics theory and finite element method.Qualified solder joints average stress intensity factorΔK_(qua) obtained by simulation and warping defect solder joints average stress intensity factorΔK_(def) obtained by simulation were compared and analyzed.By looking for influence factors and influence rules,the definition of warping factor was proposed,and the applicability was verified through simulation.The average errors between the average stress intensity factors obtained by simulation analysis and theoretical derivation are less than 6%.Experiments show that the average accuracy of the warping defect solder jointΔK_(def) corrected by warping factor is as 84.6%.