Head protection with cyclist helmet in impact against vehicle A-pillar
Head protection with cyclist helmet in impact against vehicle A-pillar
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DOI：
10.1080/13588265.2016.1259952
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发表时间：
2017-05
影响因子：
1.9
通讯作者：
K. Mizuno;D. Ito;Keiji Oida;Goichi Kobayashi;Yong Han
中科院分区：
文献类型：
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作者：
K. Mizuno;D. Ito;Keiji Oida;Goichi Kobayashi;Yong Han
摘要在车辆与骑自行车的人的碰撞中，骑自行车的人的头部经常撞击车辆的挡风玻璃和a柱。事故分析表明，刚性a柱撞击造成头部损伤的风险较高。本文从试验和有限元分析两方面研究了自行车头盔在撞击a柱时的头部保护作用。头部碰撞试验采用带头盔和不带头盔的行人头部进行。在35 km/h的a柱碰撞中，HIC从无头盔（4815）大幅降低到有头盔（3000），但远高于损伤可接受水平（1000）。由于头部的高冲击速度和a柱的刚度，头盔在撞击a柱时对头部的保护可能受到限制。头罩撞击有限元模拟结果表明，a柱撞击时头罩衬垫局部变形并呈底变形，而a柱的变形较小。在对带顶帽的人头模型进行有限元分析时，未发生颅骨骨折，但脑应变较大。通过对a柱撞击头部加速度的简单模型分析，得出头盔衬垫对头部碰撞加速度的影响较小，而a柱在5 ~ 7 kN的变形力水平下可使头盔撞击头部碰撞加速度减小到1500以下。
ABSTRACT In vehicle–cyclist collisions, the head of cyclists impacts frequently against the windshield and the A-pillar of the vehicle. Accident analyses show that the head injury risk is high in impacts with stiff A-pillars. In this research, the head protection with cyclist helmets in impacts against the A-pillar was investigated from experiments and finite element (FE) analyses. The headform impact tests were conducted using the pedestrian headform with and without a cyclist helmet. In the A-pillar impact at 35 km/h, the HIC reduced substantially from without helmet (4815) to with helmet (3000) though it was far above the injury acceptance level (1000). The head protection by helmets in impacts against A-pillars might be limited because of high impact velocities of the head and A-pillar stiffness. The FE simulations of the headform impacts indicated that the helmet liner deformed locally and bottomed-out in the A-pillar impacts, whereas the A-pillar deformation was small. In the FE analysis of a human head model with a capping helmet, the skull fracture did not occur but the brain strain was large. From a simple model of the head acceleration in the A-pillar impact, it was shown that the helmet liner has little effect on the HIC, whereas a deforming A-pillar with a force level of 5–7 kN could reduce the HIC of the head with helmets less than 1500.