Abstract: In response to the challenges posed by the updated European new car assessment programme 2026 rating protocol (Euro NCAP 2026), which replaces the Hybrid III 50th male dummy with the Hybrid III 5th female dummy in the front passenger seat for the 50% overlap moving progressive deformable barrier (MPDB) test and introduces lower leg injury assessment, this paper investigates the exceeding tibia index (TI) of the female dummy in a new vehicle model. High-speed video and biomechanical data analysis identified the primary cause as excessive upward rotation of the lower leg and its subsequent rigid impact with the lower dashboard. To suppress this motion, an optimization strategy is proposed by modifying the front footwell carpet block to increase its inclination angle. The original 40°design is adjusted to 43°and 45°for comparative testing. The results demonstrate that as the carpet inclination angle increased, the upward motion of the dummy's lower leg is effectively suppressed, leading to a significant reduction in lower leg bending moments and the tibia index. The 45°configuration proved optimal, reducing the exceeding tibia index in the right lower tibia from 1.35 to 0.29, a decrease of 78.5%, thus meeting regulatory requirements. This study confirmes that increasing the carpet inclination angle is an effective and feasible method for mitigating lower leg injury, and provides a practical reference for vehicle safety development in complying with the new regulation.

Key words: vehicle safety; offset collision; female dummy; lower leg injury; parameter optimization; Euro NCAP 2026

摘要： 针对欧洲新车安全评鉴协会 2026 年测试评级规程（Euro NCAP 2026）新规将正面 50% 重叠移动渐进变形壁障（MPDB）碰撞工况中的副驾假人由 Hybrid Ⅲ 50th 男性假人更换为 Hybrid Ⅲ 5th 女性假人，并新增小腿损伤考核所带来的挑战，文章以某新车型为对象，研究 其副驾女性假人小腿胫骨指数（TI）超标问题。通过高速摄像与力学数据分析，明确损伤主 因为碰撞过程中假人小腿过度上抬，与仪表板下部发生刚性冲击。为抑制该运动，提出了通 过改制前排脚坑处地毯垫块以提高地毯倾角的优化方案，将原 40°倾角分别调整为 43°与 45°进行对比验证。试验结果表明，随地毯倾角增大，假人小腿上抬现象得到有效抑制，小 腿弯矩与胫骨指数显著下降；其中 45°方案效果最优，使超标的右下胫骨指数从 1.35 降至 0.29，降幅达 78.5%，满足法规要求。研究证实提高地毯倾角是一种有效、可行的小腿损伤改 善方法，并为相关车型在应对新规安全开发中提供了实践依据与解决方案。

关键词: 汽车安全；偏置碰撞；女性假人；小腿损伤；参数优化；Euro NCAP 2026