Two-phase modeling of conduction mode laser welding using smoothed particle hydrodynamics

Abstract

The process of conduction mode laser welding is simulated using the meshless Lagrangian method Smoothed Particle Hydrodynamics. The modeling of the solid phase is based on the governing equations in thermoelasticity. For the liquid phase, surface tension effects including the Marangoni force caused by a temperature-dependent surface tension gradient are taken into account to simulate the melt flow in the weld pool. A non-isothermal solid-liquid phase transition with the release or absorption of additional energy known as the latent heat of fusion is considered. The major heat transfer process through conduction is modeled, whereas heat convection and radiation are neglected. The energy input from the laser beam is approximated as a Gaussian heat source acting on the material surface. Numerical results obtained with the developed model are presented for laser spot welding and seam welding of aluminum. The change of process parameters like welding speed and laser power, and their effects on the weld pool dimensions can be investigated through simulations, and the overall welding quality may be assessed.