Citation

Tanaka Y, Yonezawa H, Hosokawa N, Matsui Y, Mizuno K, Yamaguchi M, Yoshida R. Proc. Int. Tech. Conf. Enhanced Safety Vehicles 2009; 2009.

Copyright

(Copyright © 2009, In public domain, Publisher National Highway Traffic Safety Administration)

DOI

unavailable

PMID

unavailable

Abstract

There are various types of child restraint systems (CRSs), and the child kinematic response behavior during a crash is different according to which CRS type is being used. In general, P3, Q3 and Hybrid III 3-year-old (3YO) dummies are used to evaluate the performance of the forward-facing CRSs in sled and crash tests. In this study, the Hybrid III 3YO and Q3 dummies were seated in 7 types of CRSs and were tested under the impact conditions specified in ECE R44. The tested CRSs include a 5-point harness and an impact shield, and their installations on the vehicle seat were accomplished by using the seat belt or the ISOFIX with a top tether. The dummy response and injury measures were compared. The neck flexed in the 5-point harness CRS and the chest deflection was small due to the shoulder harness restraint. In the impact shield CRS, the chest was loaded and the chest deflection was large. The chest deflection in the impact shield CRS depends on the shield structure, and it was small when the shield supported the pelvis. For the 5-point harness CRS, the injury measures of the dummy were smaller in the ISOFIX CRS with a top tether than in the seat belt installed CRS, especially that for the head excursion. For the impact shield CRS, the injury measures were comparable between the ISOFIX CRS with a top tether and in the seat belt installed CRS. The global dummy kinematic behavior was comparable between the Hybrid III 3YO and Q3 dummies, though the Q3 showed more flexible behavior. The less-stiff characteristics of the Q3 affected the head kinematic behavior. In the 5-point harness CRS, the neck tension force of the Q3 was higher than that for the Hybrid III 3YO, possibly because the Q3 head severely contacted the chest due to its less-stiff neck. The chest deflection of the Q3 was larger than that of Hybrid III 3YO. This large chest deflection was more prominent for the impact shield CRS where the chest was directly loaded. The bottoming-out of the chest occurred for the Hybrid III 3YO seated in the impact shield CRS. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0242.pdf