ROLLOVER AND DROP TESTS - THE INFLUENCE OF ROOF STRENGTH ON INJURY MECHANICS USING BELTED DUMMIES. IN: OCCUPANT AND VEHICLE RESPONSES IN ROLLOVERS

This chapter on roof strength and injury mechanics is from a comprehensive text on occupant and vehicle responses in rollovers. In this chapter, the authors report on a 1985 study that examined the effects of roof strength on belted occupants in rollovers. The authors present the results of three test programs: human volunteers statically inverted in a 1983 Chevrolet Malibu to measure head excursion while wearing the lap/shoulder belt; eight dolly rollover tests with lap/should belted dummies (four cars had rollcages and four had production roofs); and five inverted vehicle drop tests using rollcaged and production roof vehicles in combination with belted and unbelted dummies. Data are presented showing dummy neck loadings resulting from head impacts to the vehicle interior as the vehicle contacts the ground. Results showed that the rollcaged and production roof vehicles rolled essentially the same distances with the same number of rolls. The centrifugal force of rollovers tends to maintain the belted occupant erect with his head upward and outboard. Neck loads resulted from diving type impacts where the head stops and the torso momentum compresses the neck. Safety belts prevented both ejections and projected impacts with the vehicle interior in the rollover tests. However, safety belts did not result in reduction of head/neck loads for dummies in the area of ground impacts.