Effect of Occupant Position and Air Bag Inflation Parameters on Driver Injury Measures 980637

This paper investigates the effects of driver airbag inflation characteristics, airbag relative position, airbag to dummy relative velocity, and steering column characteristics using a finite element model of a vehicle, air bag, and Hybrid III 50% male dummy. Simulation is conducted in a static test environment using a validated finite element model. Several static simulation tests are performed where the air bag module's position is mounted in a rigid steering wheel and the vertical and horizontal distances are varied relative to the dummy. Three vertical alignments are used: one position corresponds to the head centered on module, another position corresponds to the neck centered on module, and the third position centers the chest on the module. Horizontal alignments vary from 0 mm to 50 mm to 100 mm. All of these tests are simulated using a typical pre-1998 type inflation curve (mass flow rate of gas entering the bag). Simulation tests are then repeated using two other airbag inflation curves. One curve is a simple 75% reduction of baseline and another that has a shorter but wider and more delayed peak that is thought to produce smaller bag pressure. Inertial effects are then explored along with steering column resistance to better simulate real accident environment.

Results indicate the benefit of keeping a minimum distance of 50 mm (2 inches) between airbag and dummy. Results also indicate benefits of less aggressive inflation. A milder inflation curve that supplies the same amount of energy but takes longer to peak may also result in reduced inflation induced injuries.