Modelling failure of joining zones during forming of hybrid parts

Abstract

Abstract. Combining diverse materials enables the use of the positive properties of the individual material in one component. Hybrid material combinations therefore offer great potential for meeting the increasing demand on highly loaded components. The use of hybrid pre-joined semi-finished products simplifies joining processes through the use of simple geometries. However, the use of pre-joined hybrid semi-finished products also results in new challenges for the following process chain. For example, the materials steel and aluminium may form brittle intermetallic phases in the joining zone, which can be damaged in the following forming process under the effect of thermo-mechanical loads and thus lead to a weak point in the final part. Due to their small thickness as well as their position in the component, the analysis of the joining zone is only possible by complex destructive testing methods. FE simulation therefore offers an efficient way to analyse the development of damage in the process design and to reduce damage by process modifications. Therefore, within this study a damage model based on cohesive zone elements is implemented in the FE software MSC Marc 2018 and calibrated using experimental local tensile tests performed under process relevant conditions.