The present study amplified findings present ed in “Examination of Rollover Crash Mechanisms” (2003), “Crash Attributes That Influence the Severity of Rollover Crashes” (2003), and “Characterization of Attributes Applicable to a Rollover Crash Severity Metric” (2004) relevant to restrained occupants. Identification of the three crash occupant populations was reviewed: unejected belted, unejected unbelted, and ejected unbelted. Belted occupants involved in multiple-vehicle rollover crashes were studied owing to their elevated serious injury rates. Harm analysis and case reviews were presented for the belted occupants involved in single-vehicle rollover crashes. Two alternate crash populations were studied owing to their injury implications and pure rollover characteristics. Multiple-vehicle rollover crash belted occupants were selected owing to the elevated injury risk associated with this crash configuration. Among belted rollover crash occupants, the injury rate for multiple-vehicle rollover crash occupants was twice as high as for single-vehicle rollover crash occupants. Among unbelted rollover crash occupants, the difference between the injury rates for the crash configurations was negligible. Single-vehicle rollover crashes with nonfixed object impacts were selected because these simulated a pure rollover situation. These impacts also excluded abruptly stopped rollover crashes, especially those for which the roof was stopped by a fixed object. From these crashes, representative cases were selected for analyses of HARM, crash mechanisms, and injury patterns. HARM is a measure of societal cost of injuries sustained by motor vehicle crash occupants. From the HARM analysis, two injured body regions were identified for further study. These were: the head and thorax. Elevated HARM values were noted in rollovers with one roof to ground contact for head injuries and the second roof to ground impact for thoracic injuries. The final section presented hard -copy case review based upon the identified injuries associated with roof to ground impacts. Head injuries in rollovers with one roof to ground contact were consistent with the work of Burel (2003), who found the highest dummy head accelerations during the first revolution. These results were based upon modeling. Thoracic injuries were divided into near-side and far-side injuries. The near-side occupant thoracic injury source was generally associated with the side hardware and the far-side occupant thoracic injury source was generally associated with the safety belt. Further, tripping acceleration was evident in most of these cases. The present work seeks to outline the tripping acceleration and complex motion phenomena predicated on the injury mechanisms identified in Eigen (2004). (Author/publisher)
Abstract