There is no doubt that lightweight micro-electric vehicles will govern the future of urban mobility due to their high compatibility with electrification and shared mobility paradigms. In this regard, the structural design of an electric vehicle is of great importance since the weight reduction not only improves the crash energy conservation but also directly enhances the driving range. Although electric microcars require a light body design, they must be rigid enough to restrain against impacts. These limitations pose a great challenge in their structural design as they may be simply deformed in relatively slight crash scenarios, which makes them almost unrepairable. Although microcars are not subjected to the same legislation as passenger vehicles, standard crash tests showed their inherent vulnerability in even slight crash scenarios. This study focuses on concurrently improving structural crashworthiness and repairability while considering lightweight requirements. To do so, a novel structural crumple zones' mechanism, referred to as HaMi, is proposed, which consists of a space frame and sacrificial energy absorbers. After mechanical modeling in CATIA and meshing in Hypermesh, crash modeling simulations were performed in LS-DYNA. It was proven that using the HaMi structure not only improves repairability but also yields extraordinary results from safety aspects in the face of realistic crash conditions. Additionally, the HaMi structure is significant from other aspects. It utilizes advanced carbon fiber-reinforced polymer (CFRP) as impact attenuators to further reduce the structural weight and improve crashworthiness simultaneously. Finally, Bronze EVP 01 was produced accordingly based on the HaMi structure as the company’s first pace toward safe and sustainable mobility. The vehicle was initially targeted to become the world’s safest vehicle in the L6e class. Bronze EVP-01 shows that a lightweight and low-cost chassis built from simple planner members and reinforced by replaceable CFRP energy absorbers can outperform its rivals concerning crashworthiness and repairability aspects.
Mr. Hamed Rezvanpour, Research and Development Engineer, Bronze Industrial Group