焊接工艺参数对温度场影响的试验与数值模拟研究

Experimental Investigation and Numerical Simulation of the Influence of Welding Process Parameters on Temperature Fields

针对焊接电流、焊接速度、焊板间隙以及焊枪偏离焊缝中心的偏心值4 个焊接工艺参数进行了TIG焊接试验和数值模拟研究。为减少试验次数,采用了正交设计方案。利用红外测温仪测量和记录了焊件正面上某些点的热循环曲线,然后采用有限元法进行三维焊接温度场的数值模拟,并同试验值进行了比较,二者基本吻合,表明数值计算模型的有效性;以此数值和试验结果为基础,结合正交试验理论,分析了上述4 个工艺参数对温度场(以某点热循环中的峰值温度为代表)的影响顺序,表明偏心值对焊接温度场的影响很大,而这一点是以往的温度场数值仿真研究中所忽视的,需要引起足够的重视。

Four process parameters including welding current, welding speed, plate gap and eccentric value due to welding gun deviating the weld center were mainly studied during TIG welding process. The orthogonal plan was used to reduce experimental numbers. The heat cycle curves of various measuring points on the upper surface of the work-pieces were firstly obtained by means of infrared measuring temperature device, then, three-dimensional FEM simulation of the welding temperature fields was studied. It shows better fitness between the numerical solutions and experimental results and effectiveness of the analysis model. Based on the numerical solutions and experimental results, the influence sequence of four process parameters on temperature fields is analyzed by orthogonal design theory. It must be noticed that the welding torch eccentric value has great influence on the temperature distribution.