Comparison between two heat source models for wire-arc additive manufacturing using GMAW process

Gas metal arc welding-based additive manufacturing is a specific approach based on wire-feed and the electric arc as an energy source. This is a potential technology for the manufacture of steel structures on a large scale due to its high deposition rate, high energy efficiency, low capital costs and flexibility in material compositions. Due to non-uniformity temperature field experienced by the component during the deposition process, complex physical phenomena can be observed in the final/resulting parts. Finite element analysis plays a significant role in the study of thermo-mechanical behavior during the AM deposition process. However, to an accurate computational analysis of AM processes, heat source modeling is one of the most fundamental aspects. In order to capture some more detailed information related to the complex physical processes observed in AM, this paper proposed a numerical simulation of the thermal behavior of the workpiece manufactured by gas metal arc welding-based additive manufacturing, as well as a comparison between the Goldak’s double-ellipsoidal heat source model and a second model that uses a Double Bi-Ellipsoid curve to describe weld pool. An experimental validation was conducted and, at the end, a comparison between these models was performed. The results showed that the proposed numerical model is suitable to simulate the thermal behavior of these parts, and both heat source models used were able to predict the thermal behavior at a chosen point at the base of the wall. However, the Double Bi-Ellipsoid model described the geometry more accurately and showed the smallest percentage differences between the numerical and experimental maximum temperatures. No significant computational differences were observed with the introduction of the Double Bi-Ellipsoid model, which makes it more accurate for this case.