Characteristics of serious head injuries in pure rollover crashes and an evaluation of their replication in a dynamic rollover test

Abstract

Serious head injuries are a major concern in light passenger vehicle rollover crashes. There are efforts in the US and Australia to assess the feasibility of developing a dynamic rollover test to evaluate the crashworthiness of a vehicle in a rollover. However, detailed information about the characteristics of serious head injuries in single-vehicle single-event, i.e. pure, rollover crashes, and regarding the capabilities of the dynamic rollover test devices chosen for the separate US and Australian investigations, is lacking. To address this knowledge gap, two crash databases are investigated to describe the characteristics of head injuries and associated crash factors for pure rollover crashes in Australia and the US. Results from 80 dynamic rollover tests are analysed to evaluate the effects various test methods have on replicating and measuring ATD head response associated with serious head injury. The structural and kinematic responses of 48 vehicles in 83 tests conducted using the Jordan Rollover System (JRS) are evaluated. Logistic regression analysis is used to assess the relationship between the structural response of JRS-tested vehicles, and the occurrence of incapacitating or fatal injury in single-vehicle rollover crashes. Finally, a human body finite element model is subjected to impact conditions identified from dynamic rollover tests to demonstrate the effect of rollover-related impact parameters on a pattern of head and spine injury observed in crash data. The original findings of this thesis include details about head injury characteristics not previously reported, a re-evaluation of head response in physical rollover tests using brain and skull injury measures that have never been reported in physical rollover tests, the first comprehensive and systematic assessment of JRS test results, the first statistical model describing the relationship between vehicle performance in a dynamic rollover test and the odds of injury in rollover crashes, and the first demonstration of the significance of rollover-related impact parameters on the production of relevant head and spine injury patterns. This thesis demonstrates that it is feasible to replicate the distinct head injury characteristics observed in pure rollover crashes in a dynamic rollover test given that specific protocols for test setup and injury assessment are provided.