Abstract: With the increasing insurance institute for highway safety (IIHS) and China insurance automotive safety index (CIASI) requirements for 25% small-offset frontal collisions, this scenario has become a critical test for vehicle front-end crashworthiness. A simulation model is established for a specific vehicle, and baseline results were analyzed. Optimization measures are proposed focusing on load path continuity, structural stiffness matching, and energy-absorbing structure coverage, including curving and integrating the upper front rail with the front longitudinal beam, adding floor longitudinal supports, and reinforcing the A-pillar and sill beam. Simulations show that these measures significantly reduce occupant compartment intrusion, improve A-pillar and sill beam deformation, and enhance overall crash performance, providing an effective reference for front-end structural design under small-offset conditions.

Key words: small overlap crash; structural optimization; crash simulation; load path

摘要： 随着美国公路安全保险协会（IIHS）和中国保险汽车安全指数（CIASI）对 25%小偏置 正面碰撞评价要求的不断提升，该工况已成为检验车身前端结构抗撞性能的关键场景。针对 某车型建立小偏置碰撞仿真模型并分析基准结果后，文章从传力路径连续性、结构刚度匹配 和吸能结构有效覆盖三个方面提出优化方案，包括上指梁弧形化并与前纵梁整合、地板下纵 梁新增支撑件、A 柱与门槛梁加强。仿真结果表明，优化方案显著降低了乘员舱关键部位的 入侵量，改善了 A 柱与门槛梁的变形模式，提升了车身在小偏置工况下的整体抗撞能力，为 该类碰撞工况下车身结构设计提供了有效参考。

关键词: 小偏置碰撞；结构优化；碰撞仿真；传力路径