Experimental Analysis of Head and Neck Loads for the Out-of-Position Occupant with Single and Dual-Stage Depowered Airbags

This study measures the head and neck responses of a 50^th percentile Hybrid III dummy subject to the deployment of a dual-stage driver airbag using the first stage only. Since the airbag is deployed using the first-stage only, the tests are representative of low-severity collisions where airbag deployment is warranted. This would correspond to a rigid barrier test for a belted driver at a speed greater than 14 mph and less than 30 mph. The responses are compared with equivalent deployments of single-stage ‘depowered’ driver airbags. The airbag modules used in this study were taken from two similar sized production vehicles of the same model year that were produced by the same manufacturer. The occupant was placed in a position with the head 9 - 9.5 cm from the steering wheel. The objective was to investigate how a dual-stage production airbag reduced neck loading on an occupant who was in close proximity to a deploying airbag.

Six tests were performed; three for each airbag type. The dummy head, neck and torso were repositioned after each test to a tolerance of ±5mm. The injury responses for the dual-stage driver airbag were significantly lower than the single-stage ‘depowered’ airbag. Maximum upper neck extension moment was reduced by 55%. Maximum upper neck axial forces were reduced by 67%. Maximum upper neck shear force was reduced by 60%. N_ij for tension-extension was reduced from 0.19 to 0.09. The injury assessment reference values were not exceeded in any of the tests.