Mizuno Koji, Iwata Kazuya, Deguchi Takashi, Ikami Takashi, Kubota Masami
Graduate School of Engineering, Nagoya University, Aichi, Japan.
Traffic Inj Prev. 2005 Dec;6(4):361-71. doi: 10.1080/15389580500255922.
Child crash dummies are conventionally used for safety performance evaluations of the child restraint system (CRS) in vehicle crash tests. To investigate injuries to various body regions of a child in detail, mathematical models are useful, and provide information that cannot be analyzed by crash dummies. Therefore, in the present research, a finite element (FE) model of a 3-year-old child has been developed by model-based scaling from the AM50 human FE model, THUMS (Total HUman body for Safety).
The dimensions of each body region were based on the anthropometry data of United States children, and material properties of child bone were estimated from data reported in the literature. Neck flexion, thorax impact responses, and torso flexion were validated against the response corridor of the 3-year-old Hybrid III dummy in calibration tests. A test of lap belt loading to the abdomen was also conducted. FE models of two different types of CRS, a 5-point harness and a tray shield CRS, were also made, and ECE R44 sled impact test simulations were conducted using the child FE model.
The characteristics of the child FE model proved to be close to the Hybrid III and child volunteer corridor. In the ECE R44 sled test simulations using the child FE model, the head movement down and head rotation were large in the 5-point harness CRS, and chest deflection was large in the tray shield CRS. In both CRS types, the whole spine flexed in the child FE model. This behavior is different from that of the Hybrid III, where the thorax spine is stiff and only the cervical spine and lumbar spine flex.
Although this child FE model has several limitations in areas such as the anatomical shapes and material properties of a child, this model can be a useful tool to examine the behavior of a child in impacts, which may be difficult to predict by using the Hybrid III dummy with its stiff thorax spine box.
在车辆碰撞测试中，儿童碰撞假人通常用于儿童约束系统（CRS）的安全性能评估。为了详细研究儿童身体各个部位的损伤情况，数学模型很有用，并且能提供碰撞假人无法分析的信息。因此，在本研究中，通过基于模型的缩放，从AM50人体有限元模型THUMS（用于安全的全人体模型）开发了一个3岁儿童的有限元（FE）模型。
每个身体部位的尺寸基于美国儿童的人体测量数据，儿童骨骼的材料特性根据文献报道的数据估算。在校准测试中，针对3岁混合III型假人的响应走廊对颈部弯曲、胸部撞击响应和躯干弯曲进行了验证。还进行了对腹部施加安全带负荷的测试。还制作了两种不同类型CRS的有限元模型，一种是五点式安全带，另一种是托盘式护罩CRS，并使用儿童有限元模型进行了ECE R44雪橇碰撞测试模拟。
事实证明，儿童有限元模型的特性与混合III型和儿童志愿者走廊接近。在使用儿童有限元模型进行的ECE R44雪橇测试模拟中，五点式安全带CRS中头部向下移动和头部旋转较大，托盘式护罩CRS中胸部变形较大。在两种CRS类型中，儿童有限元模型中的整个脊柱都发生了弯曲。这种行为与混合III型不同，混合III型中胸部脊柱僵硬，只有颈椎和腰椎发生弯曲。
尽管这个儿童有限元模型在儿童的解剖形状和材料特性等方面存在一些局限性，但该模型可以成为研究儿童在碰撞中行为的有用工具，而使用胸部脊柱僵硬的混合III型假人可能难以预测这种行为。
