Numerical simulation of temperature distribution during discontinuous welding of 5A06 aluminum alloy

On the basis of infrared measurement, the temperature distribution on T-joints of 5A06 aluminum alloy cylinder structure was simulated by finite element method, developing a composite heat source constituted by Gauss heat source on the surface and inner double ellipsoid heat source. In the simulation, the effect of boundary condition such as convection and radiation etc on welding heat cycle was taken accounts of synthetically. The parameters of the composite heat source were calculated and calibrated. The orthogonal experiment was designed according to the parameters of double ellipsoid heat source and then the heat source parameters were estimated by multiple index regression analysis with analytical method. Compared with infrared measurement, the shape of simulated weld pool is rather correct, and the error of temperature is within 7% in welding heat cycle. It is feasible to simulate the temperature distribution of aluminum alloy's MIG welding using the composite heat source.