壳单元应用于薄板多道焊焊接数值模拟的方法探讨

针对目前薄板焊接残余应力有限元数值模拟中效率不高的情况,采用基于薄壳和复合层理论的壳单元来取代3D实体单元进行薄板多道焊数值模拟以预测残余应力方法的尝试,通过使用定义壳单元截面材料点数鼍来表征薄板厚度,在热分析中依靠解析方法得到温度分布,使用ABAQUS及多个用户子程序来完成力场残余应力分析的实现,通过与传统的3D单元模型计算薄板多道焊模拟的结果分析可知,采用复合层壳单元进行较为复杂的薄板焊接模拟效率相对较高,而精确度并没有下降.

Discussion on numerical simulation of multi-pass welding of thin-plate based on shell element

To solve the problem of low efficiency in simulation of multi-pass welding of thin plate by finite element method, a new method, which substitutes routine 3D solid element modeling with laminated shell element modeling based on the theory of thinshell and composite layer, was used to thermo-mechanically simulate the single or multi-pass welding of thin plate and to predict the residual stress.For the laminated shell element, the shell section points with changeable material properties were used to describe the thickness of plate.A classic analytical model was used to solve the transient temperature distribution and then ABAQUS linking some extended user subroutine was used to analyze the stress.By comparing the residual stress obtained from this method with that based on the solid-element method, the simulation efficiency of this method is higher and the precision is equivalent to that of the solid element method.