Munjurulimana, D. and Chaturvedi, M., "Monolithic, Lightweight, and Pedestrian-Safe Thermoplastic Energy-Absorbing System for Automobiles," SAE Technical Paper 2015-26-0168, 2015, doi:10.4271/2015-26-0168.
With a significant increase in awareness of safety and sustainability among the automobile original equipment manufacturers and end users, every car manufacturer is looking for lightweight, safe and cost-effective solutions for every unit present in their vehicle. The latter gets much more focus in developing countries, where the automobile market is extremely cost sensitive. Further, with implementation of the proposed global technical regulations on pedestrian safety in the near future and low-speed vehicle damageability requirements, demand for a low-cost, lighter and safer bumper system is ever increasing.This paper focuses on development of a unique thermoplastic energy-absorbing device for vehicle bumpers. Conventionally, major energy absorbing members of these bumper systems consist of three separate pieces: energy absorber, bumper beam and crash cans. A hybrid approach based on logical reasoning and topology optimization is used to conceive the design. Conceived device is an integrated assembly combining bumper beam, pedestrian-safe energy absorber and side crash cans/boxes. The proposed system offers high performance during pedestrian impacts and also meets low-speed impact requirements. The system, which is intended to be mounted over the rails/cross members, acts as an alternative to the existing bumper systems with significant reduction in the system mass.