Thermomechanical modeling and simulation of an electric arc welding process: a computacional analysis of the influence of the element birth and death techinique

Abstract

Arc welding plays a vital role in modern industry, particularly in the fabrication of complex structures and components. While the process is widely employed and relatively straightforward, it is not without challenges. Welding can introduce residual stresses, distortions, and defects into the material, potentially compromising structural integrity, increasing costs, and necessitating rework. To address these challenges, this study conducts a detailed thermomechanical analysis of the welding process, exploring computational modeling as a viable alternative to traditional experimental methods. The research employs ANSYS® software and the Finite Element Method (FEM) to simulate the thermal and mechanical behavior of materials under specific welding conditions. The study focuses on single-pass butt welding of plates and pipes, incorporating filler metals and utilizing the Element Birth and Death Technique (EBDT) to simulate material addition during welding. By examining different mesh element orders (linear and quadratic), the analysis evaluates temperature distributions, residual stresses, and deformations while also considering computational efficiency. The results revealed that EBDT increased test duration by 16.5%, and a significantly temperature difference (665ºC with EBDT vs. 348ºC without) during heat source passage. Mesh element order notably influenced outcomes: quadratic elements reduced the element count by 85%, balancing accuracy and computational efficiency, while refined linear elements increased execution time by up to 90%. For the heat-affected zone (HAZ), simulations without EBDT may suffice, but weld bead analysis requires further validation, particularly in multi-pass welding, where reheating alters stress distributions. The methodology was validated through comparisons with analytical, numerical, and experimental data available in the literature, confirming its robustness for structural analysis and process optimization. This research contributes to the theoretical understanding of arc welding, offering a computational framework that effectively balances precision and cost. The study lays a strong foundation for future investigations, especially in exploring the complexities of multi-pass welding.