Safety Performance of a Rear Seat Belt System with Optimized Seat Cushion Design

A rear seat belt system with a submarining-preventing seat design was developed. The seat has a contoured floor pan with a pronounced ridge at the front end and a seat belt with carefully located attachment points.

Sled tests simulating 30 mph barrier crashes were run with both a standard Part 572 dummy and a Part 572 dummy with a modified pelvis. Both dummies had pelvis mounted submarining indicators.

Comparative tests were run with a rear seat with a flat floor pan.

The tests proved the efficacy of the ridge type seat in preventing submarining as well as giving low injury criteria.

The modified pelvis was found to have submarining characteristics slightly different from the Part 572 pelvis. Under certain conditions the submarining indicators were capable of detecting when the lap belt loads the abdomen, but failed in some cases where the pelvis rotation was excessive.