Debora OBKIRCHER
Optimization of extruded aluminium profiles for battery tray protection in electrical cars
High energy absorption is one of the most important design criteria in the automotive industry. At the same time, low weight is required, since fuel consumption and the range of electrical cars depend significantly on the weight. Two ways to achieve better overall performance are the use of materials with a favourable strength-to-weight ratio and structural optimization. In particular, Al-Mg-Si alloys, which have a high strength-to-weight ratio and exhibit high mouldability, are often used for crushing components in cars e.g. bumper systems or battery containers. The alloying constituents of aluminium are decisive for the characteristic properties, which is why new compositions are frequently tested to achieve enhanced ductility and strength. FE-based numerical simulations can be effectively used to simulate crushing responses without the need for time-consuming and material-intensive testing if a valid constitutive model and a correct discretization of the geometry are established. In this work, an approach to establish an appropriate constitutive model based on experimentally performed tensile tests for aluminium alloys is described. Besides, a numerical model of a crash box is established and validated against experimental data. Structural design is particularly in demand where optimized material compositions are already used. In this work, it is investigated whether the energy absorption of a multi-chamber battery container can be increased by changing the geometric shape of the profile, considering different load cases. To validate the numerical material model used for the optimization, quasi-static and dynamic component tests are performed. Additionally, the influence of different discretization approaches of the profile is examined and the response behaviour is compared.