Development and validation of a parametric child anthropomorphic test device model representing 6-12-year-old children

Jun Wu, Jingwen Hu, Matthew P. Reed, Kathleen D. Klinich (University of Michigan Transportation Research Institute), Libo Cao (Hunan University)

Children from 6 to 12 year-old (YO) restrained in motor vehicles by seatbelts designed for adults often experience poor belt fit that results in adverse outcomes in crashes. Computer modelling provides a means to investigate the effects of body size on the injury risks in crashes beyond the few sizes of anthropomorphic test devices (ATDs) that are available. In this study, a parametric ATD model capable of representing 6–12 YO children was developed using MADYMO. A more realistic representation of pelvis and abdomen geometry, modified joint stiffness and improved contact characteristics were  added to a MADYMO model of the Hybrid-III 6 YO ATD. The new parametric ATD model was validated against results from 12 sled tests using real second-row vehicle seats with Hybrid III 6 YO and 10 YO ATDs under different restraint configurations using a multi-objective optimisation method. The model validity was evaluated by statistical assessments of output measurements between the tests and simulations. Results showed that the model-predicted ATD head, chest and pelvis accelerations, as well as the seatbelt forces were in good agreement with those from the tests. This validated parametric child ATD model provides a useful tool to investigate the body size effects and to develop restraint system design guidelines for 6–12 YO child occupants.