Crashworthiness Analysis of Front Impact Beam with Various Sectional Shapes for Lightweight Electric Vehicles

The weight reduction of electric vehicles is essential for improving energy efficiency and reducing carbon dioxide emissions, especially with advances in battery technology. This study proposes a lightweight front impact beam design that assembles the best-performing crash box and main bar into a complete structure. Unlike previous studies that evaluated the assembled components by modifying internal structures, this study first conducted performance tests on individual parts and then performed system-level tests on assembled components. Through this sequential approach, crashworthiness was enhanced by optimizing the system using finite element analysis. By modifying the thickness and internal structures of the crash box and main bar, the study evaluates the specific energy absorption (SEA) of various cross-sectional shapes as a crashworthiness parameter. The crash box with circular and cross ribs, showed a 15.14% SEA improvement, while the main bar, enhanced with internal ribs, achieved a 22.91% SEA increase compared to the original designs. When combined, the finite element model was validated by comparing with impact test results of the best front impact beam design. The proposed front impact beam demonstrated a SEA value of 4.228 kJ/kg at 15 KPH, indicating a crashworthiness improvement of 26.1% and a weight reduction of 15.58% compared to the original design. These findings show an effective methodology for designing lightweight with crashworthy structures, contributing to the development of more efficient and sustainable electric vehicles.