Rear-Facing Child Restraint Systems in Rear Impact Sled Tests

This study examines the performance of rear-facing child restraint systems (RF CRS) in moderate severity rear impact sled tests. The study also investigates the effects of RF CRS features on CRS kinematics and anthropomorphic test device (ATD) injury metrics in this scenario. Twelve tests were conducted at a moderate severity rear impact sled pulse (approximately 28.2 km/h and 18.4 g). Four models of RF CRS were tested in the rear outboard positions of a sedan seat. The CRABI 12-month-old and Hybrid III 3-year-old ATDs were instrumented with head and chest accelerometers, head angular rate sensors, six-axis upper neck load cells, and a chest linear potentiometer (3-year-old only). The effects of carry handle position, occupant size, presence of anti-rebound bar, Swedish style tethering, and lower anchor vs. seat belt installation were investigated. Data were also compared to pediatric injury assessment reference values (IARV). Head Injury Criterion (HIC15) values ranged from 9.6 to 89.2. Chest resultant accelerations (3 ms duration) ranged from 21.3 to 39.9 g. Neck loads and head contact against seat structures varied depending on the features of the CRS. The results indicate that RF CRS mitigate crash forces with a variety of methods in the moderate severity rear impacts performed in this series. This study provides experimental data to address this crash scenario, which are currently lacking in the literature. These conclusions are supported by epidemiological and field data which indicate RF CRS provide good protection for young occupants.