Investigation on crashworthiness characterisation of 6xxx-series aluminium sheet alloys based on local ductility criteria and edge compression tests

In order to satisfy continuously increasing regulations, further improvement of crash performance proves to be one of the major technological challenges of modern automotive engineering. It is crucial to have detailed specifications of material properties available that allow strategic material selection for various applications in future car body design. Within the scope of this work, local ductility of three 6xxx-aluminium sheet alloys is investigated based on evaluation of the localised necking behaviour in post-uniform phases of tensile tests (e.g. true fracture strain). The considered ductility criteria are gained by optical, analytical and fracture surface measurement methods. In addition to that, fracture propagation investigations are carried out to refine the ductility characterisation. The potential of local ductility characterisation methods is validated with results of the Edge-Compression Test (ECT) which allows quantification of material ductility at load conditions that occur in actual crash events.