The influence of increased roof strength on belted and unbelted dummies in rollover and drop tests

This report condenses and summarizes two related and previously published reports. These two reports analyzed the effect of added roof strength on both belted and unbelted dummies. The reports, which have been dubbed Malibu I and Malibu II, respectively, presented data from a total of 16 rollover crash tests and four test conditions in which vehicles were dropped on their roofs. To evaluate the effect of roof strength, half of all test vehicles were modified to incorporate rigid rollcages, the other half were production vehicles. To evaluate the effect of belt restraints, half of all tests incorporated restrained dummies, the other half were unrestrained. The data from these tests clearly demonstrated that increased roof strength provided no reduction in dummy neck loads for belted or unbelted dummies when they were located over the area of the roof that impacted the ground. The tests also demonstrated that the neck loads resulted from "diving" type impacts, where the head stops and the torso momentum loads the neck. Roof deformation never caused the dummy to be compressed between the roof and seat.