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The debate surrounding roof deformation and occupant injury potential has existed in the automotive community for over 30 years. In analysis of real-world rollovers, assessment of roof deformation and occupant compartment space starts with the post-accident roof position. Dynamic movement of the roof structure during a rollover sequence is generally acknowledged but quantification of the dynamic roof displacement has been limited. Previous assessment of dynamic roof deformation has been generally limited to review of the video footage from staged rollover events. Rollover testing for the evaluation of injury potential has typically been studied utilizing instrumented test dummies, on-board and off-board cameras, and measurements of residual crush. This study introduces an analysis of previously undocumented real-time data to be considered in the evaluation of the roof structure's dynamic behavior during a rollover event.

The mechanics of on-road, friction-induced rollovers were studied with the aid of a three-dimensional computer code specifically derived for this purpose. Motions of the wheels, vehicle body, occupant torso, and head were computed. Kane's method was utilized to develop the dynamic equations of motion in closed form. On-road rollover kinematics were compared to a dolly-type rollover at lesser initial speed, but generating a similar roll rotation rate. The simulated on-road rollover created a roof impact on the leading (driver's) side, while the dolly rollover simulation created a trailing-side roof impact. No head-to-roof contacts were predicted in either simulation. The first roof contact during the dolly-type roll generated greater neck loads in lateral bending than the on-road rollover. This work is considered to be the first step in developing a combined vehicle and occupant computational model for studying injury potential during rollovers.

Testing methods and SAE Recommended Practices were developed for evaluating both the ability of a truck cab to resist roof loading in a rollover environment and the occupant kinematics and injury potential for occupants in a 90-degree heavy truck rollover. In evaluating a heavy truck roof for its ability to resist rollover loads, real-world accident data was analyzed and full-scale tests were performed to define the rollover environment. It was found that testing methods currently in place for passenger cars were not sufficient to represent the loading mechanisms that typically occur in a heavy truck rollover. An SAE Recommended Practice (RP) for both dynamic and quasi-static roof load testing was developed, and tests were conducted to evaluate their use. To evaluate heavy truck occupant safety in a 90-degree rollover, independent of roof intrusion, a rollover simulator was developed. The simulator allows occupant restraints, seats, and interiors to be evaluated for injury mechanisms.