The use of micro-mechanical material laws to describe the deformation and failure behaviour of aluminium weld joints, Part II

The deformation and failure behaviour of weld joints depends not only on the load situation and the shape, size and position of production or operation-related defects, but also on the size, position and mechanical properties of the various material zones (base metal, weld metal, heat-affected zone), which determine the local stresses and the material's local resistance to crack propagation. For such complex situations, micro-mechanical methods offer the possibility of calculating the behaviour of components under load. However, the micro-mechanical models developed in the first instance for steels have not yet been verified for aluminium materials. In this work the modified Gurson model was used to give a numerical description of ductile damage in the various material zones of an aluminium weld joint. Along with this, metallography was used to quantify micro structural parameters that correspond to the set of parameters relevant for the Gurson model. The aim of these investigations was in particular to identify physically appropriate input parameters for numerical simulation of the damage process, and to examine the extent to which these allow correct prediction of the deformation and failure behaviour of MIG-welded AlMgSi profiles.