Numerical simulation of weld formation in laser plus GMAW hybrid welding

On the basis of the geometry characteristics of laser + GMAW (gas metal arc welding)pulsed hybrid welds and the macroscopic mechanism of heat transfer, four new kinds of adaptive combined volumetric heat source modes were developed. The arc heat flux, thermal contents of overheated droplets and laser power were described as double-elliptic planar distribution, double-ellipsoid body distribution, and peak value increasing-rotary curve body distribution, respectively. To apply the developed adaptive combined volumetric heat source modes into numerical analysis of temperature profiles in hybrid welding, the geometry and dimension of hybrid welds were predicted under different conditions. Through comparing the calculated results with the experimental measurements, it is found that both match well. The four kinds of adaptive combined volumetric heat source modes fully considered the process features of hybrid welding, could numerically simulate the weld dimension accurately, and reflected quantitatively the varying regularity of temperature profiles in hybrid welding.