Development of child finite element (FE) models and vehicle-to-pedestrian collision simulations

Ito, Keisuke; Tokuyama, Mie; Miyazaki, Hiroshi; Hayashi, Shigeki; Kitagawa, Yuichi; Yasuki, Tsuyoshi

This paper describes the development of child body finite element (FE) models and possible head injury mechanisms in vehicle-to-pedestrian collisions, while comparing the impact kinematics between child and adult models. Total Human Model for Safety (THUMS) Version 4 child models of 3-year-old (3YO), 6-year- old (6YO), and 10-year-old (10YO) were developed. The model geometry was generated based on computed tomography (CT) scan image data of actual pediatric subjects. The material properties of body components were defined for each model considering the age. Forty-eight vehicle-to-pedestrian collision simulations were conducted using three types of vehicle FE models (a sedan, SUV, and minivan), four sizes of pedestrian FE models (THUMS 3YO, 6YO, 10YO, and AM50) and four collision speeds (10, 20, 30, and 40 km/h). Strain based indicators were used for estimating head injuries such as skull fractures and brain injuries. The 3YO model predicted skull fracture in a collision with a SUV or minivan. Skull fractures were not observed with the other models. The child models commonly showed higher cumulative strain damage measure (CSDM) values in the brain compared to the AM50 model. Contact between the head of the child models and the front end of the hood generated stress concentration in the skull and resulted in skull fracture. The head angular acceleration of the child models increased after the shoulder contact. This high angular acceleration resulted in higher CSDM values in the brains of the child models.

Year

Entry

2009

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2011

Loyd AM. Studies of the Human Head from Neonate to Adult: An Inertial, Geometrical and Structural Analysis With Comparisons to the ATD Head [PhD thesis]. Duke University; 2011.

2011

Kent R, Lopez-Valdes FJ, Lamp J, Lau S, Parent D, Kerrigan J, Lessley D, Salzar R. Characterization of the pediatic chest and abdomen using three post-mortem human subjects. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.

2005

Mizuno Y. Summary of IHRA pedestrian safety WG activities (2005): proposed test methods to evaluate pedestrian protection afforded by passenger cars. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.

2003

Okamoto M, Takahashi Y, Mori F, Hitosugi M, Madeley J, Ivarsson J, Crandall JR. Development of finite element model for child pedestrian protection. In: Proceedings of the 18th International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 19-22, 2003; Nagoya, Japan.