Interactions between rearward-facing child restraint systems and the center console in frontal impact sled tests

Objective

To quantify the head and chest injury metrics associated with a pediatric anthropomorphic test device (ATD) in rearward-facing infant child restraint system (CRS) models positioned directly behind a center console during frontal impact sled tests.

Methods

Sled tests using the Federal Motor Vehicle Safety Standard (FMVSS) 213 frontal crash pulse were performed. The test buck comprised a second row middle seat and center console from the same 2023 model mid-size SUV spaced as per the in-vehicle relative dimensions, a force plate covered with an automotive floor mat, a post-mounted shoulder belt simulating the in-vehicle roof-mounted seatbelt and an array of high-speed cameras. The 12-month-old Child Restraint/Air Bag Interaction (CRABI-12) ATD was seated in one of two rearward-facing infant CRS models (model A, rigid lower anchors; model B, flexible lower anchors), which was installed with either the base (support leg or no support leg; attached using lower anchors or the seatbelt) or without the base (attached using the European or US belt path). Conductive foil was attached to the rear surface of the center console and to the shell of the CRS and/or base to quantify contact. The vehicle seat was replaced every second test and the center console was replaced when damaged.

Results

For sled tests of the CRS models with a base attached using lower anchors, there was no contact of the CRS with the center console when the support leg was used, and all head and chest injury metrics were reduced compared to the tests of CRS with no support leg. However, there was contact between the CRS and the center console when the base of the CRS models was attached using the seatbelt, which typically increased head and chest injury metrics compared to the lower anchor attachment method. For CRS model B with the base attached using either the lower anchors or the seatbelt but no support leg, head acceleration 3 ms clip exceeded the injury assessment reference value (IARV) of 80 g. All tests resulted in HIC36 values below the IARV of 1000. The tests of the CRS models without a base using the European belt path did not result in contact and had the lowest head and chest injury metrics of all tests, which were all below IARVs. For the tests of the CRS models with the base attached using the seatbelt and tests using the US belt path, chest acceleration 3 ms clip values exceeded the IARV of 60 g. Peak normal support leg reaction forces in this study ranged from 3.6 to 4.3 kN.

Conclusions

The rearward-facing CRS models with a base and a support leg attached using lower anchors, or without a base using the European belt path, resulted in the lowest head and chest injury metrics due to not contacting the center console.