Description of anisotropic deformation and ductile fracture of aluminium automobil components by using a micromechanical model

It is of increasing importance in the automotive industry to reduce development time and costs by virtual prototyping. The accuracy of the numerical methods depends essentially on the assessment of material properties and on the correct modelling of the material behaviour. Especially, the simulation of material damage is important for the development of next-generation ASF (Audi Space Frame) technology. In this paper, the deformation and fracture behaviour of two aluminium base materials and two heat affected zones from a welded joint is characterised by tests with miniature specimens and simulated with the modified Gurson model which describes the influence of stress triaxiality and loading rate on the damage development with a good accuracy. To verify the transferability of the damage parameters between different specimen sizes and forms, tension tests on flat tensile specimens and notched flat tensile specimens were conducted and simulated by using the Gurson parameters determined w ith miniature specimens. Finally, a component test under crash loading was modelled with the same material data. The anisotropic deformation behaviour of sheets of one aluminium alloy is evaluated and analysed with the Hill model which has been implemented into a finite element program in combination with the Gurson flow function