Compatible finite element modelling of laser welded region for crash analysis of autobody assemblies

Abstract

This paper proposes a compatible modelling method for finite element analysis of the laser welding for autobody assemblies in the crash analysis. The fracture modes of a laser weld were investigated for application to finite element modelling. A single laser weld in a stitch shape was modelled by a cluster of beam elements or hexahedron elements. The model was then applied to a cross tension test and a lap shear test under the quasi-static loading condition both experimentally and numerically. Finite element analyses were carried out with respect to the element type, the number of elements and the panel mesh size. The numerical result was compared with experimental results under the same condition. Analysis results demonstrate that the load acting on the laser welded element is accurately calculated by the change of the element type and the location of welded constrains. The method proposed provides a guideline for accurate finite element modelling of the laser welded region for the crash analysis of vehicles.