Development of rollover injury assessment instrumentation and criteria

Paver, J. G.; Friedman, D.; Carlin, F.; Bish, J.; Caplinger, J.

Abstract

This study is part of an ongoing research project aimed at mitigating catastrophic human neck injuries in rollovers. To date, U.S. rollover standards test only vehicle structural crashworthiness; there is no regulatory rollover occupant protection requirement based on dummy injury criteria, as there are for frontal and side crashes. Dynamic vehicle rollover test devices have been developed like the Controlled Rollover Impact System and the Jordan Rollover System, which realistically recreate rollover neck injury impact scenarios and use human surrogates to evaluate occupant protection. At present, the Hybrid III dummy is considered to be the best available human surrogate for dynamic rollover tests. However, there are known biofidelity and instrumentation limitations associated with the use of this dummy to predict known catastrophic human neck injury potential in real-world rollover crashes. The biggest challenges have been:

the interpretation of occupant data measured with this non-biofidelic dummy, and
the development of injury criteria for its stiff aligned neck that correlate to the more compliant human neck.

Recent research questions the use of peak injury measures (i.e., upper neck compression and, more recently, the Nij) as the criteria for catastrophic human neck injury in rollover tests.

This study investigated the use of the non-biofidelic Hybrid III dummy in a dynamic rollover test to accurately predict the predominant human neck bending injury sustained in real-world rollover crashes. The Hybrid III dummy was specially instrumented to measure biomechanical parameters to evaluate human neck bending injury potential in rollovers. An empirical relationship between upper and lower Hybrid III neck loading was derived. The effects of neck preflexion angle, roof impact speed, roof crush, onset-to-peak neck axial forces and moments, and impact duration on neck bending injury were identified. The “nutcracker effect” was investigated. Peak neck injury measures were rejected and a neck flexion injury criteria, the integrated bending moment (IBM), was proposed that related catastrophic human neck bending injury to Hybrid III lower neck moment-time histories. Dynamic validation and comparison of the IBM with other injury criteria in dynamic tests was discussed.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/bio/proceedings/2008_36/36-4.pdf

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Cited By (1)

Year	Entry
2011	Friedman D, Mattos G, Paver J. The development of a dynamic rollover rating test. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.