Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding

Purpose – The purpose of this paper is to present original methods related to the modeling of material deposit and associated heat sources for finite element simulation of gas metal arc welding (GMAW). Design/methodology/approach – The filler deposition results from high frequency impingements of melted droplets. The present modeling approach consists of a time-averaged source term in the mass equation for selected finite elements in the fusion zone. The associated expansion of the mesh is controlled by means of adaptive remeshing. The heat input includes a volume source corresponding to the droplets energy, for which a model from the literature is expressed in coherency with mass supply. Finally, an inverse technique has been developed to identify different model parameters. The objective function includes the differences between calculations and experiments in terms of temperature, but also shape of the fusion zone. Findings – The proposed approach for the modeling of metal deposition results in a direct calculation of the formation of the weld bead, without any a priori definition of its shape. Application is shown on GMAW of steel 316LN, for which parameters of the model have been identified by the inverse method. They are in agreement with literature and simulation results are found quite close to experimental measurements. Originality/value – The proposed algorithm for material deposit offers an alternative to the element activation techniques that are commonly used to simulate the deposition of filler metal. The proposed inverse method for parameter identification is original in that it encompasses an efficient and convenient technique to take into account the shape of the fusion zone