Assessment of Bilateral Thoracic Loading on the Near-Side Occupant Due to Occupant-to-Occupant Interaction in Vehicle Crash Tests

<b>Objective:</b> This study aims, by means of the WorldSID 50th percentile male, to evaluate thoracic loading and injury risk to the near-side occupant due to occupant-to-occupant interaction in combination with loading from an intruding structure.<b>Method:</b> Nine vehicle crash tests were performed with a 50th percentile WorldSID male dummy in the near-side (adjacent to the intruding structure) seat and a THOR or ES2 dummy in the far-side (opposite the intruding structure) seat. The near-side seated WorldSID was equipped with 6 + 6 IR-Traccs (LH and RH) in the thorax/abdomen enabling measurement of bilateral deflection. To differentiate deflection caused by the intrusion, and the deflection caused by the neighboring occupant, time history curves were analyzed. The crash tests were performed with different modern vehicles, equipped with thorax side airbags and inflatable curtains, ranging from a compact car to a large sedan, and in different loading conditions such as car-to-car, barrier, and pole tests. Lateral delta <i>V</i> based on vehicle tunnel acceleration and maximum residual intrusion at occupant position were used as a measurement of crash severity to compare injury measurements.<b>Result:</b> In the 9 vehicle crash tests, thoracic loading, induced by the intruding structure as well as from the far-side occupant, varied due to the size and structural performance of the car as well as the severity of the crash. Peak deflection on the thoracic outboard side occurred during the first 50 ms of the event. Between 70 to 150 ms loading induced by the neighboring occupant occurred and resulted in an inboard-side peak deflection and viscous criterion. In the tests where the target vehicle lateral delta <i>V</i> was below 30 km/h and intrusion less than 200 mm, deflections were low on both the outboard (20–40 mm) and inboard side (10–15 mm). At higher crash severities, delta <i>V</i> 35 km/h and above as well as intrusions larger than 350 mm, the inboard deflections (caused by interaction to the far-side occupant) were of the same magnitude or even higher (30–70 mm) than the outboard deflections (30–50 mm).<b>Conclusion:</b> A WorldSID 50th percentile male equipped with bilateral IR-Traccs can detect loading to the thorax from a neighboring occupant making injury risk assessment feasible for this type of loading. At crash severities resulting in a delta <i>V</i> above 35 km/h and intrusions larger than 350 mm, both the inboard deflection and VC resulted in high risks of Abbreviated Injury Scale (AIS) 3+ injury, especially for a senior occupant.

<b>研究目的：</b> 本研究借助第50百分位男性WorldSID侧面碰撞假人（WorldSID），评估乘员-乘员交互作用结合侵入结构载荷对近侧乘员造成的胸部载荷与损伤风险。<b>研究方法：</b> 共开展9次车辆碰撞试验：近侧座椅（紧邻侵入结构的一侧）放置第50百分位男性WorldSID侧面碰撞假人（WorldSID），远侧座椅（与侵入结构相对的一侧）放置THOR碰撞假人（THOR）或ES2碰撞假人（ES2）。该近侧座椅上的WorldSID假人于胸部/腹部区域配备左、右两侧各6组的红外轨迹传感器（IR-Traccs），可实现双侧位移测量。为区分侵入结构引发的位移与相邻乘员引发的位移，研究人员对时间历程曲线进行了分析。试验所用车辆涵盖紧凑型轿车至大型轿车等多款现代车型，均搭载胸部侧气囊与充气帘，且涵盖车对车碰撞、壁障碰撞、柱碰撞等多种碰撞工况。研究以基于车辆隧道加速度得到的侧向ΔV以及乘员位置处的最大残余侵入量作为碰撞严重程度的评价指标，用于对比各项损伤测量结果。<b>试验结果：</b> 在9次车辆碰撞试验中，由侵入结构与远侧乘员共同引发的胸部载荷，会因车辆尺寸、结构性能以及碰撞严重程度的不同而存在差异。胸部外侧（靠近侵入结构侧）的峰值位移出现在碰撞事件的前50毫秒内；在70~150毫秒区间内，相邻乘员引发的载荷开始作用，进而导致胸部内侧（靠近相邻乘员侧）出现峰值位移与粘性准则（VC）数值升高。当目标车辆侧向ΔV低于30 km/h且残余侵入量小于200 mm时，胸部外侧（20~40 mm）与内侧（10~15 mm）的位移均处于较低水平。当碰撞严重程度提升，ΔV达到35 km/h及以上且残余侵入量大于350 mm时，由远侧乘员交互引发的内侧位移幅值可与外侧位移（30~50 mm）持平，甚至更高（30~70 mm）。<b>研究结论：</b> 搭载双侧红外轨迹传感器（IR-Traccs）的第50百分位男性WorldSID侧面碰撞假人，可检测到相邻乘员对胸部施加的载荷，使得此类载荷下的损伤风险评估具备可行性。当碰撞严重程度达到侧向ΔV超过35 km/h且残余侵入量大于350 mm时，内侧位移与粘性准则（VC）均会导致乘员面临较高的简明损伤定级标准（AIS）3级及以上损伤风险，老年乘员尤为显著。