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The performance of inflatable toepan padding for mitigating lower limb injuries was investigated. A rigid multi-body model was used to describe the scenario of an occupant in an automobile frontal crash with toepan intrusion. The emphasis was placed on the lower limb responses during impact. The interaction between the lower limbs and the inflatable toepan padding was described by the contact between the feet and the load distribution plate of the padding. Computational simulations were performed to analyze the effects of the controlled motion of this plate on the lower limb impact responses.

Two series of tests were conducted to investigate the performance of ejection seat cushions for safety and comfort, respectively. In the safety study, seven operational and prototype cushions were tested on the vertical deceleration tower, where the cushions were placed between the seat pan and the occupant (a 50th percentile Hybrid III manikin) and subjected to +Gz impact at 8, 10, and 12 g, respectively. In the comfort investigation, twenty volunteer subjects (12 females and 8 males) with a range of anthropometry were tested on four operational and prototype cushions over eight-hour durations. The safety performance of a cushion is evaluated by the impact transmissibility from the carriage acceleration to the peak lumbar load, whereas the sitting comfort performance is assessed in terms of the peak contact pressure and subjective survey data.

Validation methods for the finite element automobile crash modeling were developed using wavelet analysis. Based on the decompositions on wavelet packet bases, two types of signal energy distributions were established with respect to: (a) frequency index, and (b) time position and frequency index, which provide a common basis for the comparison between the simulation results and the test data in terms of the variation of amplitue with respect to frequency and time. Based on the decompositions on wavelet bases, correlation analysis was used to evaluate the differences in pulse shape and peak timing between the simulation results and the test data for the gross motions and major impact pulses. The use of the methods was illustrated in the validation of a 1997 Honda Accord finite element model for full frontal impact.