Development and testing of a more realistic pelvis for the hybrid III 6-year-old ATD
Authors: Kathleen D. Klinich, Matthew P. Reed, Miriam A. Manary, and Nichole R. Orton.
Objective: Design and test a new pelvis for the Hybrid III 6-year-old (6YO) anthropometric test device (ATD) with a more humanlike bone structure, flesh contour, and flesh stiffness intended to provide more realistic interaction with belt restraints. Methods: Target geometry for the new pelvis bone was based on a 3D model of the skeletal pelvis derived from statistical analysis of pediatric computed tomography (CT) scans. The current pelvis bone was reshaped to better match the target geometry, with a particular emphasis on the contour in the areas of belt interaction. The prominence representing the anterior-superior iliac spine (ASIS) was lowered by 15 mm. The pelvis flesh was molded using softer vinyl while maintaining a 10-mm flesh margin over the ASIS. A series of 20 sled tests was conducted to compare the performance of the modified pelvis with the current Hybrid III pelvis. Results: In a series of sled tests using a range of belt anchorage locations, a dummy equipped with the new pelvis did not submarine in conditions where the lap belt was positioned below the ASIS. Tests run with the lap belt initially positioned over the ASIS resulted in submarining, unlike tests performed with the standard dummy pelvis. Conclusions: The new pelvis for the 6YO Hybrid III ATD better represents the skeletal and flesh geometry of similar-sized children. The ATD equipped with the new pelvis is more sensitive to lap belt geometry than the standard ATD. The modified ATD may provide an improved assessment of booster seats and belt restraints intended for child occupants.