On the Synergism of the Driver Air Bag and the 3-Point Belt in Frontal Collisions

Abstract

Forty-eight kph frontal collisions were performed using human cadavers. The results show, that by using a combined standard 3-point belt (6% and 16% elongation)/driver air bag, the thoracic injury pattern remained located under the shoulder belt. Chest contours derived from the chest bands showed high local compression and deformation of the chest along the shoulder belt path. In tests where the air bag was the only available torso restraint, forces were distributed uniformly over the front of the chest. This study investigates if it is possible to obtain both the thoracic injury mitigating benefits of an air bag only restraint and the all-impact-direction benefits of the belt from a combination restraint system by adding a force limiter to the shoulder belt. For this reason, tests with force limiters were performed. Initially, the investigation was carried out with Hybrid III dummies using two different levels of force limiters: 4 kN and 5 kN.By using the same restraint combination and force limiter, comparable vertebral accelerations and chest compressions were measured in cadaver testing. Analytical simulations were also conducted using different size occupants in both the baseline and the optimized belt/air bag restraint and in other crash conditions. For the covering abstract of the conference see IRRD 882980.