NASS/CDS delta-V estimates: the influence of enhancements to the WinSmash crash reconstruction code

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Hampton, Carolyn E.¹; Gabler, Hampton C.¹

NASS/CDS delta-V estimates: the influence of enhancements to the WinSmash crash reconstruction code

53rd Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM)

Affiliations

¹Center for Injury Biomechanics, Virginia Tech
Abstract

The change in velocity (delta-V) crash severity metric in the NASS/CDS (National Automotive Sampling System / Crashworthiness Data System) is computed using the WinSmash crash reconstruction code. Beginning in 2008, NASS/CDS investigators have started to use an enhanced version of WinSmash, WinSmash 2008, which features a comprehensive vehicle specific library for over 5000 vehicle make-model-year combinations and updated categorical stiffness values. The use of WinSmash 2008 is expected to greatly improve delta-V estimates. However, there is concern that this may result in a step change in the NASS/CDS delta-V estimates, making it difficult to compare NASS/CDS 2008 with earlier years. A total of 1,808 collisions were recomputed using data from NASS/CDS 2007. The new version of WinSmash shows improved accuracy, but still underpredicts delta-V. The use of WinSmash 2008 increased the delta-V by 7.9% or 1.9 kph on average. The changes in delta-V were not evenly distributed. Delta-V increases were larger for side impacts (8.3%) than for back impacts (5.3%). The calculation type had little effect on the delta-V changes. For vehicles, pickup trucks showed a small increase (3.3%) and utility vehicles increased the most (9.6%). This jump in delta-V may prevent the data from NASS/CDS 2008 and later from being readily aggregated with previous years.

Cited Works (2)

Year	Entry
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2010	Hampton CE, Gabler HC. Evaluation of the accuracy of NASS/CDS delta-V estimates from the enhanced winsmash algorithm. In: 54th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 17-20, 2010; Las Vegas, NV.241-251.
2010	Kusano KD, Gabler HC. Potential occupant injury reduction in pre-crash system equipped vehicles in the striking vehicle of rear-end crashes. In: 54th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 17-20, 2010; Las Vegas, NV.203-213.
2011	Rhule H, Mallory A, Hagedorn A. Real world older occupant crash data and sensitivity of THOR-NT and WorldSID dummy thoraces. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.
2017	Gabler HC, Sharma D. Accuracy of WinSMASH in rear crashes using event data recorders. In: Proceedings of the 25th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 5-8, 2017; Detroit, MI.
2016	Klinich KD, Flannagan CAC, Hu J, Reed MP. Potential safety effects of low‐mass vehicles with comprehensive crash avoidance technology. In: Proceedings of the 2016 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2016; Malaga, Spain.755-764.
2020	Chen W, Zhou Q, Gan S, Nie B. Generating a large-scale numerical database of motor vehicle crashes for rapid injury severity prediction. In: Proceedings of the 2020 International IRCOBI Asia Conference on the Biomechanics of Injury. 2020; Beijing, China.25-28.
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