Simulation Of Heat Transfer In GMAW Process

Gas metal active welding is one of the most popular welding methods in the world industrial production now. Simulation of Heat Transfer in GMAW Process is very important for welding intellectualized to get control parameters.Based on theories of heat transfer, numerical simulation analysis model for GMAW was created. A double ellipsoid heat source mode was adopted to depict the distribution of a moving GMAW arc. The effects of moving arc on the distribution of both arc heat flux and arc pressure are taken into consideration and the mathematical expressions of double- ellipsoid distribution modes for both arc heat flux and arc pressure are given out. The temperature distribution of the whole work piece under heat source can be solved through the addition of the effective arc temperature fields and the droplet thermal enthalpy temperature fields produced by heat source. Then, the discrete forms of the governing equations and pool surfaces deformation equations are established, and additional source term method is utilized to discretize both energy and momentum boundary conditions. The computational algorithms are designed and numerical simulation program are complied and built, which have modular forms of the software structure to enhance the readability and maintainability and to raise the flexibility and adaptability.Through applying the equations of the top surfaces deformation of pattial-penetrated weld pool, the dynamic development of weld pool surfaces deformation are simulated for partial--penetration. The transient variation of the maximum hump, the maximum depression is examined.By using the model and program developed in this study, the transient variation of temperature profile, weld pool geometry and weld pool surfaces deformation are numerically simulated for stainless steel workpieces in GMAW. GMAW experiments on mild steel plates are carried out, and the geometrical parameters of molten pool are measured. .The result of comprising technical test with model show that the model and calculated method are correct and credible.