Creating an Instantaneous Center of Rotation Map to Determine the Influence of Yaw Rate on Occupant Kinematics and Injury Potential in Eccentric Planar Collisions
2022-01-0993
03/29/2022
- Content
- The reconstruction of planar vehicle-to-vehicle collisions often requires a kinematic analysis of post-impact occupant motion to assist with biomechanical injury assessment. When one vehicle imparts an eccentric force on the adverse vehicle, the resulting vehicle kinematics include both translation and rotation. The influence of vehicle yaw on occupant kinematics has been well established. The role that the vehicle yaw has with regard to occupant injury potential is dependent upon a number of factors, including delta-V, vehicle intrusion, occupant seating position, restraint use, and yaw rate. Assuming rotation about the vehicle center of gravity or trivializing post-impact rotation may overlook aspects of the collision dynamics that have important implications for post-impact occupant motion. This study examines the significance of vehicle yaw on occupant kinematics and the evaluation of injury potential in eccentric planar collisions. The paper describes the calculation of the instantaneous center of rotation (ICR) in a yawing vehicle post-impact and then explores the relevant parameters that affect an occupant’s trajectory when using a free-particle “occupant” analysis. The ICR is presented as a useful mechanism to visualize the vehicle kinematics in an eccentric planar collision. The study presents the calculated ICR from eccentric vehicle-to-vehicle crashes to create a geometric characterization map. It was found that the ICR map can inform the crash analyst or the biomechanist about the influence that the post-impact yaw rate will have on an occupant’s motion after the collision impulse has occurred. The study focuses on nine separate occupant seat positions in a minivan and several hypothetical examples of eccentric vehicle-to-vehicle crash configurations with varying delta-V and yaw rate. The ICR map technique is applied to each crash scenario to illustrate which crash conditions and corresponding seating positions are most influenced by post-impact vehicle yaw rate in the analysis of occupant kinematics in these crash modes.
- Citation
- Rapp van Roden, E., and Zolock, J., "Creating an Instantaneous Center of Rotation Map to Determine the Influence of Yaw Rate on Occupant Kinematics and Injury Potential in Eccentric Planar Collisions," SAE Technical Paper 2022-01-0993, 2022, .