The association between vehicle rim type and risk of occupant injury

Modern vehicles generally use steel fabricated or alloy blended rims. The manufacturing process and atomic structure of the rim both yield different responses under destructive loading. The aim of this research was to investigate to what extend the type of vehicle rim may influence occupant injury risk. A matched cohort study of frontal German In-Depth Accident Study collisions was devised. The risk of injury to various body regions was compared between vehicles with steel and alloy rims. Occupants in vehicles with alloy rims were at a greater risk of thoracic injury (relative risk [RR] = 1.57; 95% confidence interval [CI], 1.01–2.42) and thoracic abdomen injury (RR = 1.62; 95% CI, 1.10–2.39) at the Maximum Abbreviations Injury Scale (MAIS) 2+ severity. Risk of thoracic injury was greatest for the cluster of occupants seated on the nonimpacted side in frontal collisions (RR = 2.21; 95% CI, 1.01–4.86). MAIS 2+ injury to the head/face/neck yielded no association (RR = 0.98; 95% CI, 0.66–1.47). Alloy rims are more brittle and, as a result, destructive loading is realized with less severe impact. The critical failure increases the amount of loading that needs to be distributed by the restraint system and results in injury.

现代乘用车普遍采用钢制加工轮毂或合金复合轮毂。轮毂的制造工艺与原子结构在承受破坏性载荷时，会表现出截然不同的力学响应。本研究旨在探究车辆轮毂类型对乘员损伤风险的影响程度。本研究设计了一项针对德国深入事故研究（German In-Depth Accident Study）中正面碰撞事故的匹配队列研究，对比了装配钢制轮毂与合金轮毂的车辆中乘员各身体部位的损伤风险。在简明损伤定级标准（Maximum Abbreviations Injury Scale, MAIS）2级及以上损伤严重程度下，装配合金轮毂的车辆乘员发生胸部损伤（相对危险度[RR]=1.57；95%置信区间[CI]：1.01~2.42）与胸腹联合损伤（RR=1.62；95%CI：1.10~2.39）的风险显著更高。正面碰撞中，坐在非碰撞侧的乘员群体发生胸部损伤的风险最高（RR=2.21；95%CI：1.01~4.86）。头/面/颈部发生MAIS 2级及以上损伤的风险与轮毂类型无显著关联（RR=0.98；95%CI：0.66~1.47）。合金轮毂脆性更高，因此在相对更低烈度的碰撞中即可发生破坏性载荷失效。这类临界失效会增加约束系统所需承担的载荷总量，进而导致乘员损伤。