T形接头双光束激光焊变形计算方法

以厚度为2.5 mm的铝锂合金5A90薄壁T形接头双光束激光焊变形为研究对象,针对焊缝金属熔化及凝固引起的材料力学行为变化,考虑筋板与底板之间连接的实现过程,开发了双光束激光焊单元生死温度判别法,焊接过程中以单元瞬态温度为判据,对单元动态杀死和激活;对比了采用与不采用单元生死温度判别法的焊接变形计算结果,该两种计算方法在材料参数、几何模型、边界条件及初始条件等方面都完全相同.结果表明,是否采用单元生死温度判别法对T形接头双光束激光焊变形的计算结果有显著影响,并对这种影响进行了分析.

Computational method for deformation of T joint welded by double beam laser

The computational method of deformation of T joint of aluminum-Li alloy with thickness of 2.5 mm welded by double beam laser was studied.By taking account of the change of mechanical characteristics of the weld metal in heating,melting, cooling and solidifying process,and the forming process of the T joint,a method of calculating the deformation of T joint welded by double beam laser welding was developed based on birth-death control by the temperature of each element.In the method,an element was killed or activated according to its temperature during welding.The welding deformation obtained by two different computational methods were compared,one using the birth-death control method,and the other not.Except the above difference,material,geometry,boundary and initial conditions were identical for the two computational methods.The results showed that,whether using the birth-death control or not, which had an important influence on the computational results of deformation of T joint welded by double beam laser welding,and the reason was analyzed.