A novel modeling approach for multi-passes butt-welded plates

Numerical simulation of welding process in the industrial field requires flexibility, speed, and accuracy at the same time. The use of conventional 3D models in detailed simulations of multi-pass welds is time-consuming, and it often slows down the design phase of large welded structures. Shell elements are usually employed in the finite element (FE) simulation of large structures like vessels and pipes. Nevertheless, employing a simple shell model to simulate multi-pass welds would most likely produce inaccurate outcomes. This article introduces a new equivalent parametric modeling methodology for the simulation of longitudinal multi-pass welds on plane structures, such as plates and rectangular hollow sections. The proposed Weld Equivalent Model (WEM) is made with single and multi-layer shell, link and beam elements. It helps detect residual stress and local distortion that are typical of multi-pass welds. This method employs thermal transient and steady-state structural analyses. The WEM model is generated by an automatic subroutine acting on a pre-existing FE shell model. In addition to this, a case study is reported of multi-pass welding of two plates featuring a V-shaped groove. This innovative weld modeling technique shows remarkable results and helps shorten computational time up to ten times compared to classical 3D numerical models.