An experimental investigation was conducted to determine the effects of certain seating and restraint parameters on the tendency for an adult rear seat passenger to submarine (i.e., for the lap belt to ride over the pelvic iliac crests and penetrate the abdomen) in a 30 mph delta-v frontal collision. Four parameters were investigated: (1) type of restraint (lap belt only or three-point belt), (2) seat cushion stiffness, (3) seat cushion height, and (4) lap belt angle (with the range from 20 to 75 degrees, as specified in FMVSS 210, "Seat Belt Assembly Anchorages"). The experiments were done on the HYGE sled, using a Hybrid III dummy with a "submarining pelvis" which contains three load cells mounted on each iliac crest to indicate lap belt location. The test matrix was a fractional factorial design, which enabled determination of the statistical significance of the parameters on submarining tendency and other occupant responses. Lap belt angle was found to be a highly significant parameter- the shallower the angle, the greater the submarining tendency. The tendency to submarine also appeared to be greater for three-point belted occupants than for lap-only belted occupants, although lap belt forces were much less for three-point belts. Results indicated that only one injury (AIS 1) would have occurred out of six cases of submarining in three-point belts. (A) For the covering abstract of the conference, see IRRD 837684.
Abstract