双相钢电阻点焊应力与变形行为数值分析  

Numerical simulation on stress and deformation behavior in resistance spot welding of dual phase steel

作　　者：万晓东[1,2] 徐靖[3] 王元勋[2] 张鹏[2] 

机构地区：[1]华中科技大学数字制造装备与技术国家重点实验室,武汉430074 [2]华中科技大学土木工程与力学学院力学系,武汉430074 [3]中航工业航宇救生装备有限公司,襄阳441022

出　　处：《焊接学报》2017年第6期79-82,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(11072083)

摘　　要：文中对DP600电阻点焊过程进行了数值模拟,分析了预压、焊接和维持阶段热力学行为.结果表明,熔核尺寸预测值与试验结果基本保持一致.相比于其它位置,熔核中心点温度在焊接阶段升高较快,而在维持阶段则下降较为缓慢.在焊接过程中,电极/工件和工件/工件接触面的接触压强变化明显,并通过工件热膨胀变形行为进行解释.在焊接阶段结束时,熔核中心区域由于热膨胀不匹配而产生径向压应力状态,这由工件的热膨胀不匹配而产生.焊点温度在维持阶段迅速下降,中心区域的压应力因此得到部分释放.另外,在模型中可以观察到与试验结果较为一致的工件间缺口及劈尖形区域.In this study,a numerical model for resistance spot welding of DP600 steel was proposed. The thermal and mechanical behaviour at squeezing,welding and holding stages were analyzed. The predicted nugget size was in good agreement with experimental results. The increasing rate of temperature at the center point was the most significant among all locations at the welding stage. Temperature of the center point decreased most slowly at the holding stage. Contact pressure variation at the workpiece/electrode interface and workpiece/workpiece interface during the welding process were very obvious,and could be explained by combining the thermal expansion behaviour of workpieces. A compressive radial stress state was found in weld central region at the end of welding stage,which was due to the thermal expansion mismatch of workpieces. A rapid temperature decrease of the spot weld could be observed at the holding stage.The compressive stress in the central region was therefore partially released. In addition,the workpiece notch and wedged region similar to experimental observation were also successfully simulated.

关 键 词：双相钢 电阻点焊 数值模拟 接触压强 应力分布 

分 类 号：TG404[金属学及工艺—焊接]