Optimization of Structural Aluminum Components for Frontal Impact Safety Performance

Today one of the most challenges in the automotive field is the emission reduction of vehicles. For this purpose, car manufacturers are trying to reduce the overall weight of their cars and in this sense the use of aluminum, instead of steel, is finding more and more space. In this wave of change, the components used for passive safety (front rails, crash boxes, crossbeams and third load paths) have also undergone a material change towards aluminum. Nowadays these components have even more challenging aims, due to more severe regulation scenarios and the introduction of hybrid and full electric models on the market. According to this not only their excellent energy absorption capabilities to protect the occupants is required, but also the ability to protect very critical high voltage components in engine bay. In the master thesis activity carried out at the Stellantis Safety Center (Orbassano), the optimization of these components has been conducted on two vehicles, still under development phase, to adapt them to the new intended purposes. In this sense, after a benchmarking analysis on direct competitors, various tests were performed at component level, in order to assess both the global behavior of the component and the material characteristics for CAE models correlation. However, these tests gave different results with respect to CAE prediction in terms of mechanical properties and folding attitude, resulting inadequate for their intended purposes. Once identified the issue, different solutions of heat treatment, alloy type and component geometry have been investigated and tested in order to optimize the behavior of the components. This activity led to the identification of the solution that better fulfill the components requirements. Once the desired results were obtained, the components were mounted on the vehicles and tested at fullscale level, confirming the good results seen previously. The ultimate goal of this activity was the definition of structural guidelines that would allow the company in future projects to start from a more advanced know-how on these aluminum components in order to save time and resources in finding the right solution.