Hu Jingwen, Reed Matthew P, Rupp Jonathan D, Fischer Kurt, Lange Paul, Adler Angelo
University of Michigan Transportation Research Institute.
Emory University School of Medicine.
Stapp Car Crash J. 2017 Nov;61:67-100. doi: 10.4271/2017-22-0004.
Recent field data have shown that the occupant protection in vehicle rear seats failed to keep pace with advances in the front seats likely due to the lack of advanced safety technologies. The objective of this study was to optimize advanced restraint systems for protecting rear seat occupants with a range of body sizes under different frontal crash pulses. Three series of sled tests (baseline tests, advanced restraint trial tests, and final tests), MADYMO model validations against a subset of the sled tests, and design optimizations using the validated models were conducted to investigate rear seat occupant protection with 4 Anthropomorphic Test Devices (ATDs) and 2 crash pulses. The sled tests and computer simulations were conducted with a variety of restraint systems including the baseline rear-seat 3-point belt, 3-point belts with a pre-tensioner, load limiter, dynamic locking tongue, 4-point belts, inflatable belts, Bag in Roof (BiR) concept, and Self Conforming Rear seat Air Bag (SCaRAB) concept. The results of the first two sled series demonstrated that the baseline 3-point belt system are associated with many injury measures exceeding injury assessment reference values (IARVs); showed the significance of crash pulse and occupant size in predicting injury risks; and verified the potential need of advanced restraint features for better protecting the rear-seat occupants. Good correlations between the tests and simulations were achieved through a combination of optimization and manual fine-tuning, as determined by a correlation method. Parametric simulations showed that optimized belt-only designs (3-point belt with pre-tensioner and load limiter) met all of the IARVs under the soft crash pulse but not the severe crash pulse, while the optimized belt and SCaRAB design met all the IARVs under both the soft and severe crash pulses. Two physical prototype restraint systems, namely an "advanced-belt only" design and an "advanced-belt and SCaRAB" design, were then tested in the final sled series. With the soft crash pulse, both advanced restraint systems were able to reduce all the injury measures below the IARVs for all four ATDs. Both advanced restraint systems also effectively reduced almost all the injury measures for all ATDs under the severe crash pulse, except for the THOR. The design with the advanced-belt and SCaRAB generally provided lower injury measures than those using the advanced belt-only design. This study highlighted the potential benefit of using advanced seatbelt and airbag systems for rear-seat occupant protection in frontal crashes.
近期的现场数据表明，车辆后排座椅的乘客保护措施未能跟上前排座椅的发展步伐，这可能是由于缺乏先进的安全技术。本研究的目的是优化先进的约束系统，以在不同的正面碰撞脉冲下保护不同体型的后排乘客。进行了三组雪橇试验（基线试验、先进约束试验和最终试验），针对部分雪橇试验对MADYMO模型进行了验证，并使用经过验证的模型进行了设计优化，以研究使用4个人形试验装置（ATD）和2种碰撞脉冲时的后排乘客保护情况。雪橇试验和计算机模拟采用了多种约束系统，包括基线后排三点式安全带、带预紧器的三点式安全带、限力器、动态锁定舌片、四点式安全带、充气式安全带、车顶气囊（BiR）概念以及自适应后排座椅安全气囊（SCaRAB）概念。前两组雪橇试验的结果表明，基线三点式安全带系统与许多超过损伤评估参考值（IARV）的损伤指标相关；显示了碰撞脉冲和乘客体型在预测损伤风险方面的重要性；并验证了先进约束功能对于更好地保护后排乘客的潜在需求。通过优化和手动微调相结合的方式，经相关方法确定，试验与模拟之间实现了良好的相关性。参数模拟表明，优化后的仅安全带设计（带预紧器和限力器的三点式安全带）在软碰撞脉冲下满足所有IARV，但在硬碰撞脉冲下不满足，而优化后的安全带和SCaRAB设计在软碰撞脉冲和硬碰撞脉冲下均满足所有IARV。然后在最终的雪橇试验系列中测试了两种物理原型约束系统，即“仅先进安全带”设计和“先进安全带和SCaRAB”设计。在软碰撞脉冲下，两种先进约束系统都能够将所有四个ATD的所有损伤指标降低到IARV以下。在硬碰撞脉冲下，两种先进约束系统也有效降低了所有ATD的几乎所有损伤指标，除了THOR。先进安全带和SCaRAB的设计通常比仅使用先进安全带的设计提供更低的损伤指标。本研究强调了在正面碰撞中使用先进安全带和安全气囊系统保护后排乘客的潜在益处。
