Optimization Study on Driver Lower Tibia Injury in MPDB

This study addresses the issue of excessive lower leg injury to the THOR dummy driver in a 50 km/h frontal 50% overlap rigid barrier collision (MPDB) for a specific vehicle model. A method to reduce lower limb injury by optimizing the foot support foam is proposed. Through simulation analysis, the effects of foam stiffness, installation angle, and other parameters on the axial force (Fz) and bending moment (My) of the lower leg are investigated. The results show that when ethylene-vinyl acetate (EVA) foam with a foaming rate of 30% and an installation angle of 45° is used, the axial force Fz of the lower leg decreases from 1.98 kN to 1.03 kN, and the tibia index (Ti) improves from 0.69 to 0.53. The lower leg score increases by 26.2%, meeting the C-NCAP target requirements. The optimization solution is validated through sled tests, demonstrating a significant reduction in lower leg biomechanical loads. This study provides a theoretical basis for the design of vehicle restraint systems.