Initial Occupant Kinematics in the High Velocity Vehicle Rollover

Predictions of occupant motion in passenger vehicles undergoing rollovers have been hampered by the uncertainties of the vehicular motion. These uncertainties arise due to a host of factors which may be difficult to quantify, such as trip conditions, vehicle/terrain interaction dynamics and mass eccentricities. In this paper the initial segment of a roll sequence of high angular velocity (greater than 4 radians per second) about a longitudinal axis is examined. The resultant unrestrained motions of the near and far side occupants are studied. To facilitate this analysis a mathematical model has been developed which incorporates dynamic characteristics of the occupant, the vehicle and the terrain surface. The analysis is carried through the first significant vehicle/ground impact following roll initiation. Occupant kinematics are described.