Pipkorn Bengt, Subit Damien, Donlon John Paul, Sunnevång Cecilia
a Autoliv Research , Vårgårda , Sweden.
Traffic Inj Prev. 2014;15 Suppl 1:S231-7. doi: 10.1080/15389588.2014.933818.
The objective of this study is to evaluate how the impact energy is apportioned between chest deflection and translation of the vehicle occupant for various side impact conditions.
The Autoliv Total Human Model for Safety (modified THUMS v1.4) was subjected to localized lateral constant velocity impacts to the upper body. First, the impact tests performed on postmortem human subjects (PMHS) were replicated to evaluate THUMS biofidelity. In these tests, a 75-mm-tall flat probe impacted the thorax at 3 m/s at 3 levels (shoulder, upper chest, and mid-chest) and 3 angles (lateral, +15° posterolateral, and -15° anterolateral), for a stroke of 72 mm. Second, a parametric analysis was performed: the Autoliv THUMS response to a 250-mm impact was evaluated for varying impact levels (shoulder to mid-thorax by 50-mm increments), obliquity (0° [pure lateral] to +20° [posterior impacts] and to -20° [anterior impacts], by 5° steps), and impactor pitch (from 0 to 25° by 5° steps). A total of 139 simulations were run. The impactor force, chest deflection, spine displacement, and spine velocity were calculated for each simulation.
The Autoliv THUMS biofidelity was found acceptable. Overall, the predictions from the model were in good agreement with the PMHS results. The worst ratings were observed for the anterolateral impacts. For the parametric analysis, maximum chest deflection (MCD) and maximum spine displacement (MSD) were found to consistently follow opposite trends with increasing obliquity. This trend was level dependent, with greater MCD (lower MSD) for the higher impact levels. However, the spine velocity for the 250-mm impactor stroke followed an independent trend that could not be linked to MCD or MSD. This suggests that the spine velocity, which can be used as a proxy for the thorax kinetic energy, needs to be included in the design parameters of countermeasures for side impact protection.
The parametric analysis reveals a trade-off between the deformation of the chest (and therefore the risk of rib fracture) and the lateral translation of the spine: reducing the maximum chest deflection comes at the cost of increasing the occupant lateral displacement. The trade-off between MCD and MSD is location dependent, which suggests that an optimum point of loading on the chest for the action of a safety system can be found.
本研究的目的是评估在各种侧面碰撞条件下，碰撞能量如何在胸部变形和车辆乘员平移之间分配。
使用奥托立夫全人类安全模型（改良的THUMS v1.4）对上半身进行局部横向等速碰撞。首先，复制在尸体人类受试者（PMHS）上进行的碰撞测试，以评估THUMS的生物逼真度。在这些测试中，一个75毫米高的扁平探头以3米/秒的速度在3个水平位置（肩部、上胸部和中胸部）和3个角度（外侧、+15°后外侧和 -15°前外侧）撞击胸部，行程为72毫米。其次，进行了参数分析：评估了奥托立夫THUMS对250毫米碰撞的响应，碰撞水平不同（肩部到中胸部以50毫米增量变化）、倾斜度不同（从0°[纯外侧]到 +20°[后部碰撞]再到 -20°[前部碰撞]，以5°步长变化）以及撞击器俯仰角度不同（从0°到25°以5°步长变化）。总共运行了139次模拟。计算每次模拟的撞击力、胸部变形、脊柱位移和脊柱速度。
发现奥托立夫THUMS的生物逼真度可以接受。总体而言，模型的预测结果与PMHS的结果吻合良好。在前外侧碰撞中观察到最差的评级。对于参数分析，发现随着倾斜度增加，最大胸部变形（MCD）和最大脊柱位移（MSD）始终呈现相反的趋势。这种趋势与碰撞水平有关，对于较高的碰撞水平，MCD更大（MSD更小）。然而，250毫米撞击器行程的脊柱速度遵循独立的趋势，无法与MCD或MSD相关联。这表明，可作为胸部动能替代指标的脊柱速度，需要纳入侧面碰撞保护对策的设计参数中。
参数分析揭示了胸部变形（以及因此肋骨骨折的风险）与脊柱横向平移之间的权衡：减少最大胸部变形是以增加乘员横向位移为代价的。MCD和MSD之间的权衡取决于位置，这表明可以找到安全系统作用于胸部的最佳加载点。
