Forman Jason L, Lopez-Valdes Francisco J, Dennis Nate, Kent Richard W, Tanji Hiromasa, Higuchi Kazuo
Center for Applied Biomechanics, University of Virginia European Center for Injury Prevention, University of Navarra School of Medicine Center for Applied Biomechanics, University of Virginia Takata Corporation.
Ann Adv Automot Med. 2010;54:111-26.
Frontal-impact airbag systems have the potential to provide a benefit to rear seat occupants by distributing restraining forces over the body in a manner not possible using belts alone. This study sought to investigate the effects of incorporating a belt-integrated airbag ("airbelt") into a rear seat occupant restraint system. Frontal impact sled tests were performed with a Hybrid III 50th percentile male anthropomorphic test device (ATD) seated in the right-rear passenger position of a 2004 mid-sized sedan buck. Tests were performed at 48 km/h (20 g, 100 ms acceleration pulse) and 29 km/h (11 g, 100 ms). The restraints consisted of a 3-point belt system with a cylindrical airbag integrated into the upper portion of the shoulder belt. The airbag was tapered in shape, with a maximum diameter of 16 cm (at the shoulder) that decreased to 4 cm at the mid-chest. A 2.5 kN force-limiter was integrated into the shoulder-belt retractor, and a 2.3 kN pretensioner was present in the out-board anchor of the lap belt. Six ATD tests (three 48 km/h and three 29 km/h) were performed with the airbelt system. These were compared to previous frontal-impact, rear seat ATD tests with a standard (not-force-limited, not-pretensioned) 3-point belt system and a progressive force-limiting (peak 4.4 kN), pretensioning (FL+PT) 3-point belt system. In the 48 km/h tests, the airbelt resulted in significantly less (p<0.05, two-tailed Student's t-test) posterior displacement of the sternum towards the spine (chest deflection) than both the standard and FL+PT belt systems (airbelt: average 13±1.1 mm standard deviation; standard belt: 33±2.3 mm; FL+PT belt: 23±2.6 mm). This was consistent with a significant reduction in the peak upper shoulder belt force (airbelt: 2.7±0.1 kN; standard belt: 8.7±0.3 kN; FL+PT belt: 4.4±0.1 kN), and was accompanied by a small increase in forward motion of the head (airbelt: 54±0.4 cm; standard belt: 45±1.3 cm; FL+PT belt: 47±1.1 cm) The airbelt system also significantly reduced the flexion moment in the lower neck (airbelt: 169±3.3 Nm; standard belt: 655±26 Nm; FL+PT belt: 308±19 Nm). Similar results were observed in the 29 km/h tests. These results suggest that this airbelt system may provide some benefit for adult rear seat occupants in frontal collisions, even in relatively low-speed impacts. Further study is needed to evaluate this type of restraint system for different size occupants (e.g., children), for out-of-position occupants, and with other occupant models (e.g., cadavers).
正面碰撞安全气囊系统有可能通过以仅使用安全带无法实现的方式将约束力量分散在身体上，从而为后排乘客带来益处。本研究旨在调查将安全带一体式安全气囊（“安全气带”）纳入后排乘客约束系统的效果。使用Hybrid III第50百分位男性人体模型（ATD）坐在2004年中型轿车车身右侧后排乘客位置进行正面碰撞雪橇试验。试验在48公里/小时（20g，100毫秒加速脉冲）和29公里/小时（11g，100毫秒）下进行。约束系统包括一个三点式安全带系统，其中圆柱形安全气囊集成在肩带的上部。安全气囊呈锥形，最大直径为16厘米（在肩部）并在胸部中部减小到4厘米。一个2.5千牛的力限制器集成在肩带卷收器中，并且在腰部安全带的外侧锚点处有一个2.3千牛的预紧器。使用安全气带系统进行了六次ATD试验（三次48公里/小时和三次29公里/小时）。将这些试验与之前使用标准（无力量限制、无预紧）三点式安全带系统和渐进式力量限制（峰值4.4千牛）、预紧（FL + PT）三点式安全带系统进行的正面碰撞、后排座椅ATD试验进行比较。在48公里/小时的试验中，安全气带导致胸骨相对于脊柱的向后位移（胸部偏移）明显小于标准和FL + PT安全带系统（安全气带：平均13±1.1毫米标准差；标准安全带：33±2.3毫米；FL + PT安全带：23±2.6毫米）（p < 0.05，双尾学生t检验）。这与肩带上部峰值力的显著降低一致（安全气带：2.7±0.1千牛；标准安全带：8.7±0.3千牛；FL + PT安全带：4.4±0.1千牛），并且伴随着头部向前运动略有增加（安全气带：54±0.4厘米；标准安全带：45±1.3厘米；FL + PT安全带：47±1.1厘米）。安全气带系统还显著降低了下颈部的弯曲力矩（安全气带：169±3.3牛米；标准安全带：655±26牛米；FL + PT安全带：308±19牛米）。在29公里/小时的试验中观察到了类似的结果。这些结果表明，即使在相对低速碰撞中，这种安全气带系统可能为正面碰撞中的成年后排乘客提供一些益处。需要进一步研究以评估这种约束系统对于不同体型乘客（例如儿童）以及失位乘客和其他乘客模型（例如尸体）的适用性。
