Lightweight and Sustainable Car Bumper Design for Pedestrian Safety Using Waste Aluminum Cans

Abstract

This study explores a sustainable and pedestrian-friendly alternative to traditional steel car bumpers by repurposing discarded aluminum beverage Cans as lightweight energy-absorbing elements. Conventional steel bumpers, while effective at protecting the vehicle, transmit high impact forces to pedestrians, increasing the risk of severe lower-limb injuries. At the same time, large quantities of recyclable aluminum cans end up as waste, presenting an opportunity for circular reuse. To address these issues, this research proposes a bumper design that utilizes recycled aluminum Cans and evaluates its performance through a combined experimental and numerical approach. Drop-weight impact tests were conducted on Cans in vertical and horizontal orientations to assess deformation behavior and energy absorption. The validated Finite Element (FE) model of the Aluminum Can was developed in LS-DYNA and validated using the experimental results of the drop weight impact test. Simulations were carried out using a FE model of the Toyota Camry vehicle model and the THUMS human body FE model to compare the recycled aluminum bumper with a conventional steel bumper under identical conditions. The results show that the aluminum-can bumper significantly reduces transmitted impact force by as much as 87% and keeps tibia and fibula stress below common fracture thresholds of 150 MPa by the Euro NCAP, indicating a meaningful improvement in pedestrian safety. The findings demonstrate that waste aluminum cans can be engineered into an effective bumper core material, offering a practical pathway toward safer and more environmentally responsible vehicle design