316L超薄板激光焊接的失稳变形规律  

Instability deformation analysis of laser welded joint of 316L ultra-thin plate

作　　者：张景祺 林健[1] 雷永平[1] 许海亮 王细波 ZHANG Jing-qi;LIN Jian;LEI Yong-ping;XU Hai-liang;WANG Xi-bo(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Beijing Institute of Astronautical System Engineering,Beijing 100076,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]北京宇航系统工程研究所,北京100076

出　　处：《材料工程》2020年第12期126-134,共9页Journal of Materials Engineering

基　　金：国家重点研发计划(2017YFB1104803);国家自然科学基金(51005004);北京市自然科学基金(3132006)。

摘　　要：基于以能量准则判定的薄板稳定理论,建立超薄板激光焊接头失稳变形的有限元模型。使用ABAQUS模拟了0.07 mm厚的316L钢箔平板堆焊的温度场和应力场,获得其固有应变的分布情况。以固有应变作为等效载荷对薄板的焊后失稳变形进行特征值屈曲分析,与实测变形结果进行对比,优化数值模型,发现在较低热输入下,超薄金属板产生凹-凸变形,在较高热输入下产生反向的凸-凹变形。讨论了薄板变形模态发生改变的原因。引入低阶特征值屈曲模态作为初始变形趋势进行非线性屈曲分析,分析失稳变形量,与实际变形测量结果基本一致。保持薄板长宽比为1∶1,改变薄板尺寸,拟合了薄板临界失稳载荷与其尺寸的数值关系。结果表明,薄板面积越小,薄板的临界屈曲载荷越大。而随着薄板厚度的增大,临界屈曲载荷显著增大。Based on the thin plate stability theory determined by energy criterion,the finite element model of unstable deformation of ultra-thin plate laser welded joint was established.The temperature field and stress field of 316L steel foil plate surfacing welding with 0.07 mm thickness were simulated by ABAQUS,and the distribution of inherent strain was obtained.The eigenvalue buckling analysis of the post-welding instability deformation behavior in thin plate was carried out by using inherent strain obtained by integral calculation as equivalent load.Compared with the measured deformation results of laser welding,it was found that the ultra-thin metal plate presents concave-convex deformation mode after lower heat input,while convex-concave deformation occurs after higher heat input in the thin plate.The parameters of the numerical model were optimized,and the reasons for the change of the deformation mode of the thin plate were discussed.The nonlinear buckling analysis was carried out by introducing the low-order eigenvalue buckling mode as the initial deformation trend,and the unstable deformation was simulated,which is basically consistent with the actual deformation measurement results.Keeping the ratio of length to width of the thin plate at 1∶1 and changing the size of the thin plate,the numerical relationship between the critical instability load and the size of the thin plate was fitted.The results show that the smaller the area of the thin plate is,the greater the critical buckling load of the thin plate is.With the increase of the thickness of the thin plate,the critical buckling load is increased significantly.

关 键 词：超薄板 激光焊 固有应变 屈曲分析 临界屈曲载荷 有限元模拟 

分 类 号：TG404[金属学及工艺—焊接]