The purpose of this study was to develop the analytical methodology to evaluate the dynamic versus residual roof deformation characteristics of a compact SUV subjected to SAE J2114 dolly rollover tests. Two FMVSS 208 dolly rollover tests with instrumented, restrained driver side Hybrid III dummies were evaluated during the first driver’s side roof rail ground strike. Kinematic targets were mounted on the driver dummy head and tracked via onboard cameras as a means of visual validation of roof rail deformation (assuming rail-to-dummy head contact). Test instrumentation included:​ accelerometers at the vehicle center of gravity (CG), roof rail, pillars and rocker panel, lap and shoulder belt load transducers, triaxial accelerometers at the center of gravity of the head, chest and pelvis of the dummies and six-axis force (and moment) transducers in the neck of the dummy. All data was recorded consistent with SAE J211-1 recommendations

Vehicle angular velocity and attitude were estimated using the data from multiple accelerometers, which correlated well with the test video. The accelerometer data indicate that the driver roof rail dynamic deformation was significantly greater than the residual deformation to which the roof rail rebounded following loss of ground contact. The dynamic deformation was of such magnitude that the rail intruded into the driver’s occupant survival space. A spike in driver dummy head acceleration was observed immediately following the acceleration pulse that caused the rail intrusion The presence of significant dynamic roof rail deformation is new and important quantitative information that should be added to the body of knowledge surrounding reconsideration of FMVSS 216 and catastrophic injury prevention in rollover crashes.