Sensitivity to Different Seating Positions of THOR-NT and Hybrid III in Sled Testing

In this study, the sensitivity to different seating positions of the THOR-NT and the Hybrid III in sled testing was evaluated. In the tests, the THOR-NT or the Hybrid III was installed on the driver seat of a vehicle body fixed on the sled, and a frontal impact of 15.6 m/s (56 km/h) was given to the sled. Dummy installation was subject to Federal Motor Vehicle Safety Standard (FMVSS) 208 and University of Michigan Transportation Research Institute (UMTRI) seating procedures. Furthermore, based on the FMVSS 208 procedure, the seat slide was adjusted forward 30 mm (MP-30). In testing of the three seating positions of the THOR-NT, different responses in the head acceleration were shown. The head accelerations in FMVSS 208 and UMTRI exhibited a sharp high wave of about 110 ms, but that in the MP-30 did not exhibit such a wave. Applying the dummy injury values to provisional injury assessment reference values (IARVs) for THOR used in the research of the National Highway Traffic Safety Administration (NHTSA), kinematic rotational brain injury criterion (BRIC) of the MP-30 was lower than FMVSS 208 and UMTRI. For the acetabulum force, it was large, in the order of the UMTRI, FMVSS 208, and MP-30. For inversion/eversion of the right ankle of the accelerator pedal side, it showed large angles, in the order of the FMVSS 208, MP-30, and UMTRI. Other injury values of the ankles showed large angles, in the order of the UMTRI, FMVSS 208, and MP-30. The difference in the responses to the different seating positions was mainly observed in the head acceleration and lower extremity force responses for both the THOR-NT and the Hybrid III. However, comparing responses of the THOR-NT and the Hybrid III with the same conditions, the upper body of the THOR-NT moved forward more, compared to the Hybrid III, and the torsion about the z-axis was also larger than the Hybrid III. As a result, the head acceleration of the THOR-NT and the Hybrid III exhibited different responses.