Pickup Truck Rollover Accident Reconstruction Using the ATB Model

To demonstrate the Articulated Total Body (ATB) model's capability to predict complex rollover accidents, a rollover accident was selected from the National Accident Sampling System (NASS) and simulated. This paper focuses on the simulation of the vehicle's dynamics which can in turn be used to specify the vehicle motion for occupant simulations. The selected accident case involved a pickup truck, crashing at high speed and completing three rolls. The pickup truck was modeled as a single rigid segment with fifteen contact hyperellipsoids rigidly attached to it. These hyperellipsoids were sized and positioned to approximate the exterior surfaces of the pickup truck. The force-deflection functions were defined based upon previous simulations of rollover tests. The initial conditions were defined to match the data in the NASS accident report as closely as possible. Angular and linear accelerations, velocities, and displacements of the vehicle were predicted and reported as well as the ground-vehicle contact forces and the resulting vehicle body deflections. The simulation results compared well with the accident description and diagrams in the NASS report. This study demonstrates that the ATB model can be used to provide a reasonable prediction of the vehicle's motion during a rollover accident using the data available in the NASS report.