A parametric study of a side airbag system to meet deflection based criteria.

A side airbag system comprising of 12 liter bag to cover the BioSid chest and the abdomen down to the arm rest level, and 75 mm of padding to cover the pelvic/thigh area was evaluated by a series of sled tests at two different velocities, 10 m/s and 12 m/s. The initial bag (over) pressure was varied from 0 to 80 kPa and the bag ventilation area was varied from zero to 1500 mm2. Compressed air was used to fill the bag. It was found that the ventilation of the bag reduced the maximum chest deflection by 30 percent and the maximum viscous criterion, VC, by 50 percent (comparison was made with the same bag without ventilation). A suitable initial bag (over) pressure was found to be about 50 kPa, when the loading of the abdomen was also taken into consideration. The results indicate that the chest deflection is proportioned to the door average velocity (during the first 20 ms of deflection) to the power of about 2 and that the VC is proportional to the same velocity to the power of about 4. It was also found that a 12 liter ventilated side airbag resulted in 30-40 percent lower chest deflection and about 60 percent lower VC than 50 mm of chest padding (Ethafoam 220).