DUMMY HEAD KINEMATICS IN TRIPPED ROLLOVER TESTS AND A TEST METHOD TO EVALUATE THE EFFECT OF CURTAIN AIRBAG DEPLOYMENT. IN: OCCUPANT AND VEHICLE RESPONSES IN ROLLOVERS

Developing a side curtain airbag system for occupant protection in tripped rollover accidents requires the knowledge of the occupant kinematics prior to tripping. In this chapter, from a comprehensive text about occupant and vehicle responses in rollovers, the authors report on a study that used the Deceleration Rollover Sled (DRS) to evaluate the effectiveness of the curtain airbag system deploy and position during the onset of a tripped rollover event. The DRS consist of a sled and a set of pulse generation deceleration brakes. The vehicle is supported by the sled and travels by a tow cable from a stationary position along a track until a certain velocity is achieved. On the leading side of the sled, there are a set of adjustable height curbs; these are used for the tripping. The deceleration brakes are preset to a calculated reaction force that is applied to the sled to simulate the desired deceleration of a tripped rollover event. Results show that as a vehicle experiences lateral deceleration prior to the trip initiation, the unrestrained dummy head is already in motion and may be close to the vehicle interior or at the side glass plane. If the vehicle is equipped with a curtain airbag system, it may be difficult to trigger the curtain deployment prior to the dummy interacting with the vehicle side structure (it is difficult to determine if the event is a roll or no-roll situation early in the event). However, for such conditions, a curtain airbag restraint system should be designed so that it deploys and positions itself properly as the dummy head is approaching the side glass plane or in the deployment zone. The authors discuss the dynamic rollover tests they used, as well as an out-of-position static test that simulates the dummy head kinematics observed in the low g (<1.5 g) dynamic test. The authors conclude that the Deceleration Rollover Sled demonstrated a repeatable test method in analyzing dummy head travel in simulated tripped rollover events.