An original FE modelling of a longitudinal multi-passes seam welding

Both finite element and analytical methods for simulation of welding are essential to predict residual stress and distortions of welded components. Best FE modelling is obtained by using solid elements for thermo-structural simulation with high computational cost. In this contest, an equivalent modelling of plates based on shell elements is proposed in order to streamline the simulations. The equivalent model is composed of n levels of shell elements, centered on the weld seam, in order to evaluate rotations and translations typical of a multi-pass weld. There are as many levels as the number of the weld passes that compose the seam. The interconnection between the n shell levels is realized by rigid beam elements. The latter ones are connected to shell elements by constraint equations. Solid brick models of the plates are used as a benchmark for the equivalent models in thermal and mechanical simulations. The equivalent modelling is in good agreement with solid results, showing a strong decrease of computational burden, enabling the simulation of large welded models in operative conditions. © 2019