Trajectory Model of Occupants Ejected in Rollover Crashes
Dr. James R. Funk, Mr. Peter A. Luepke
2007 SAE World Congress (SP-2063), Detroit, MI, April 16-19, 2007. Warrendale, PA. Society of Automotive Engineers. 2007; 9 pp. SAE # 2007-01-0742.
A simple two-dimensional particle model was developed to predict the airborne trajectory, landing point, tumbling distance, and rest position of an occupant ejected in a rollover crash. The ejected occupant was modeled as a projectile that was launched tangentially at a given radius from the center of gravity of the vehicle. The landing and tumbling phases of the ejection were modeled assuming a constant coefficient of friction between the occupant and the ground. Model parameters were optimized based on a dolly rollover test of a 1998 Ford Expedition in which five unbelted anthropomorphic test devices (ATDs) were completely ejected. A generalized vehicle dynamics model was also created assuming a constant translational deceleration and a prescribed roll rate function. Predictions using the generalized model were validated against the results of the full-scale rollover test to estimate the expected error when using the model in a real-world situation. The model was shown to be a useful tool for investigating possible ejection points and occupant trajectories in rollover crashes.
Copyright © 2007 SAE International. This article is posted on this website with permission from SAE International. This article is for viewing only, and may not be reprinted, copied, distributed or forwarded without permission from SAE.