Despite the considerable rollover crashworthiness research carried out to date, there is still a need to establish exactly how spine and neck injuries occur to a seat-belted occupant during a rollover. This paper details an experimental and Finite Element (FE) analysis aimed at demonstrating how a stronger vehicle roof can reduce the potential for neck injuries to a seat belted occupant seated in the front on the rollover far-side.
An analysis was carried out of the head-torso kinematics of a seat-belted Anthropomorphic Test Device (ATD) measured during two rollover crash tests conducted on a weak- and strong-roof sport utility vehicle (SUV), respectively. Both experimental laboratory rollover tests were performed under the same nominal conditions using the original Center for Injury Research (CFIR) Jordan Rollover System (JRS) located in Goleta, California. Further, a comparison of the ATD kinematics was then carried out using data obtained from detailed FE simulations of vehicle rollovers carried out using the FE model of the University of New South Wales (UNSW) JRS located in Sydney Australia, and an FE model of a SUV, first with the original production roof and then with a reinforced roof.
The analysis of the experimental tests indicated that an excessive roof crush would likely cause the head to be captured within the crush zone long enough for the torso to apply a large inertial axial-compression load to the neck. In contrast, a stronger roof continuously guides the occupant’s head moving it along an arc in a smoother manner, thus reducing any significant change in velocity between the head and torso, and any consequent inertial axial-compression loading. However, preliminary computer simulations confirm this mechanism only in part, and further simulations of the refined computer model of the UNSW JRS and SUV models are being conducted and will be reported on when completed.