Kapoor Tanya, Altenhof William, Howard Andrew, Rasico Jim, Zhu Fuchun
Department of Mechanical, Automotive and Materials Engineering, University of Windsor, 410 Sunset Avenue, Windsor, Ontario, Canada N9B 3P4.
Accid Anal Prev. 2008 Nov;40(6):1880-92. doi: 10.1016/j.aap.2008.07.008. Epub 2008 Sep 5.
This research focuses on the injury potential of children seated in forward-facing child safety seats during side impact crashes in a near-side seated position. Side impact dynamic sled tests were conducted by NHTSA at Transportation Research Center Inc. (TRC) using a Hybrid III 3-year-old child dummy seated in a convertible forward/rearward child safety seat. The seat was equipped with a LATCH and a top tether and the dummy was positioned in forward-facing/near-side configuration. The test was completed using an acceleration pulse with a closing speed of 24.1 km/h, in the presence of a rigid wall and absence of a vehicle body. A fully deformable finite element model of a child restraint seat, for side impact crash investigations, has been developed which has also been previously validated for frontal and far side impacts. A numerical model utilizing a Hybrid III 3-year-old dummy, employing a similar set-up as the experimental sled test was generated and simulated using LS DYNA. The numerical model was validated by comparing the head and the chest accelerations, resultant upper and lower neck forces and moments from the experimental and numerical tests. The simulation results were observed to be in good agreement to the experimental observations. A numerical model of the near-side laboratory tests, utilizing a Q3s child dummy, was also created for parametric studies regarding different ISOFIX configurations. Further, numerical simulations were completed for both the dummy models with rectangular and cross-shaped sections of rigid ISOFIX systems. In addition, studies were conducted to confine lateral movement of the dummy's head by adding energy absorbing foam on the side wings in the vicinity of the contact region of the CRS. It was observed that the use of rigid ISOFIX system reduced the lateral displacement of the CRS and different injury parameters. Addition of energy absorbing foam blocks was effective in further reducing the lateral displacement of the dummy's head. The lateral displacement of the head was reduced by 68 mm by using cross-shaped section ISOFIX with energy absorbing foam near the vicinity of the head of the Hybrid III 3-year-old dummy compared to the flexible LATCH configuration without foam. For the Q3s dummy, the lateral displacement of the head was reduced by 48 mm by utilizing a cross-shaped section rigid ISOFIX system with the addition of energy absorbing foam compared to the flexible LATCH configuration.
本研究聚焦于坐在前向儿童安全座椅上处于近侧就座位置的儿童在侧面碰撞事故中的受伤可能性。美国国家公路交通安全管理局（NHTSA）在运输研究中心公司（TRC）进行了侧面碰撞动态雪橇试验，使用一个安装在可转换前向/后向儿童安全座椅中的Hybrid III 3岁儿童假人。该座椅配备了下固定点和顶部系绳，假人处于前向/近侧配置。试验在有刚性壁且无车身的情况下，以24.1公里/小时的闭合速度使用加速度脉冲完成。已经开发了一个用于侧面碰撞事故调查的儿童约束座椅全可变形有限元模型，该模型先前也已针对正面和远侧碰撞进行了验证。利用LS DYNA生成并模拟了一个使用Hybrid III 3岁假人的数值模型，其设置与实验雪橇试验类似。通过比较实验和数值试验中头部和胸部的加速度、颈部上下合力及力矩，对数值模型进行了验证。观察到模拟结果与实验观测结果吻合良好。还创建了一个使用Q3s儿童假人的近侧实验室试验数值模型，用于关于不同ISOFIX配置的参数研究。此外，针对刚性ISOFIX系统的矩形和十字形截面的两种假人模型都完成了数值模拟。另外，通过在儿童约束系统（CRS）接触区域附近的侧翼添加能量吸收泡沫，进行了限制假人头部横向移动的研究。观察到使用刚性ISOFIX系统减少了CRS的横向位移和不同的伤害参数。添加能量吸收泡沫块有效地进一步减少了假人头部的横向位移。与没有泡沫的柔性下固定点配置相比，在Hybrid III 3岁假人头部附近使用带有能量吸收泡沫的十字形截面ISOFIX，头部的横向位移减少了68毫米。对于Q3s假人，与柔性下固定点配置相比，使用带有能量吸收泡沫的十字形截面刚性ISOFIX系统，头部的横向位移减少了48毫米。
