Wu Taotao, Kim Taewung, Bollapragada Varun, Poulard David, Chen Huipeng, Panzer Matthew B, Forman Jason L, Crandall Jeff R, Pipkorn Bengt
a Center for Applied Biomechanics , University of Virginia , Charlottesville , Virginia.
b Department of Mechanical Design Engineering , Korea Polytechnic University , Siheung-si , Gyeonggi-do , Korea.
Traffic Inj Prev. 2017 May 29;18(sup1):S148-S154. doi: 10.1080/15389588.2017.1318435.
The goal of this study was to evaluate the biofidelity of the Total Human Model for Safety (THUMS; Ver. 4.01) pedestrian finite element models (PFEM) in a whole-body pedestrian impact condition using a well-characterized generic pedestrian buck model.
The biofidelity of THUMS PFEM was evaluated with respect to data from 3 full-scale postmortem human subject (PMHS) pedestrian impact tests, in which a pedestrian buck laterally struck the subjects using a pedestrian buck at 40 km/h. The pedestrian model was scaled to match the anthropometry of the target subjects and then positioned to match the pre-impact postures of the target subjects based on the 3-dimensional motion tracking data obtained during the experiments. An objective rating method was employed to quantitatively evaluate the correlation between the responses of the models and the PMHS. Injuries in the models were predicted both probabilistically and deterministically using empirical injury risk functions and strain measures, respectively, and compared with those of the target PMHS.
In general, the model exhibited biofidelic kinematic responses (in the Y-Z plane) regarding trajectories (International Organization for Standardization [ISO] ratings: Y = 0.90 ± 0.11, Z = 0.89 ± 0.09), linear resultant velocities (ISO ratings: 0.83 ± 0.07), accelerations (ISO ratings: Y = 0.58 ± 0.11, Z = 0.52 ± 0.12), and angular velocities (ISO ratings: X = 0.48 ± 0.13) but exhibited stiffer leg responses and delayed head responses compared to those of the PMHS. This indicates potential biofidelity issues with the PFEM for regions below the knee and in the neck. The model also demonstrated comparable reaction forces at the buck front-end regions to those from the PMHS tests. The PFEM generally predicted the injuries that the PMHS sustained but overestimated injuries in the ankle and leg regions.
Based on the data considered, the THUMS PFEM was considered to be biofidelic for this pedestrian impact condition and vehicle. Given the capability of the model to reproduce biomechanical responses, it shows potential as a valuable tool for developing novel pedestrian safety systems.
本研究的目的是使用一个特征明确的通用行人碰撞模型，评估全身体安全行人有限元模型（THUMS；版本4.01）在全身行人碰撞条件下的生物逼真度。
根据3次全尺寸尸体行人碰撞试验的数据评估THUMS有限元模型的生物逼真度，在这些试验中，一个行人碰撞模型以40公里/小时的速度横向撞击受试者。行人模型按比例缩放以匹配目标受试者的人体测量学特征，然后根据实验期间获得的三维运动跟踪数据进行定位，以匹配目标受试者的碰撞前姿势。采用一种客观评分方法来定量评估模型响应与尸体行人碰撞试验数据之间的相关性。分别使用经验损伤风险函数和应变测量方法对模型中的损伤进行概率预测和确定性预测，并与目标尸体行人碰撞试验数据的损伤情况进行比较。
总体而言，该模型在轨迹（国际标准化组织[ISO]评分：Y = 0.90±0.11，Z = 0.89±0.09）、线性合成速度（ISO评分：0.83±0.07）、加速度（ISO评分：Y = 0.58±0.11，Z = 0.52±0.12）和角速度（ISO评分：X = 0.48±0.13）方面表现出生物逼真的运动学响应（在Y-Z平面），但与尸体行人碰撞试验数据相比，腿部响应更硬，头部响应延迟。这表明有限元模型在膝盖以下和颈部区域存在潜在的生物逼真度问题。该模型在碰撞前端区域也表现出与尸体行人碰撞试验数据相当的反作用力。有限元模型通常能预测尸体行人碰撞试验数据中所受的损伤，但高估了脚踝和腿部区域的损伤。
基于所考虑的数据，THUMS有限元模型在这种行人碰撞条件和车辆情况下被认为具有生物逼真度。鉴于该模型具有再现生物力学响应的能力，它显示出作为开发新型行人安全系统的有价值工具的潜力。
