A human body model of a female post-mortem human subject (PMHS) was created by anthropometric scaling of the THUMS adult male 50th perc. finite element model. The kinematic response of the scaled human model was correlated by means of PMHS sled tests. The force-displacement responses of the seat, the seat belt and an inflatable pelvis restraint cushion (PRC) of the finite element sled model were correlated by means of Hybrid III 50th perc. mechanical sled tests.

The scaled THUMS model was positioned in the sled model and its response correlated in 56km/h by means of one PMHS test with a standard seat and two PMHS tests with a seat-mounted PRC. Accelerations and displacements in the head, chest and pelvis together with pelvis rotations, belt forces and seat forces from the model were compared to that of three PMHS sled tests. For the scaled THUMS models, a CORA rating of 0.75 was obtained using the standard seat and 0.76 using the seat-mounted PRC.

The correlated scaled THUMS model was then used for investigating how the lap belt position and a seat- mounted PRC affects pelvis kinematics and the risk of submarining. The investigation was carried out for a belted passenger side occupant in the vehicle interior of a mid-sized sedan. The risk for submarining was measured by recording the distance between the pelvic bone anterior superior iliac spine (ASIS) points to three points on the lap belt.

Lap belt positions with the belt midpoint 55mm (baseline) and 86mm (upper) above ASIS were investigated. In general, increased pelvis displacements and increased risk of submarining was obtained for the upper compared to the baseline lap belt position. Compared to a system without lap belt pretensioner and PRC, pelvis displacements were reduced by 12% and 9% using a lap belt pretensioner and by 61% using the PRC for the baseline and upper positions respectively. Rearward pelvis rotations were reduced by 56% using the PRC for both lap belt positions while slightly increased rearward pelvis rotations was obtained using the lap pretensioner. Using both the lap pretensioner and the PRC, pelvis displacements were reduced by 71% for the baseline position and by 70% for the upper position. Based on the submarining distance measurement, submarining was prevented using the PRC for both lap belt positions. Additional reduction in the risk of submarining was obtained by combining lap pretensioning with the PRC.