Extended finite-elements for spot-welded structures simulation

This paper presents an enriched bilinear quadrilateral thin shell element for spot welded structures modelling. This element, is implemented as an Abaqus user element. The base element is a Simo-Rifai quadrilateral. The present, treatment of spot welds is inspired from the inclusion problem treatment in the extended finite element framework. Each spot weld is considered as a point detail in the steel sheet 2D continuous medium; the enrichment functions to the displacement approximation space are chosen to represent accurately the local deformation modes near the spot weld, and give an acceptable representation of the deformed assembled steel sheets without requiring an explicit meshing of spot welds. Numerical examples demonstrate the method capability to model spot welded structures from independently obtained steel sheets meshes.