Real world older occupant crash data and sensitivity of THOR-NT and WorldSID dummy thoraces

Rhule, Heather; Mallory, Ann; Hagedorn, Alena

Affiliations

¹National Highway Traffic Safety Administration

²Transportation Research Center Inc., United States

Abstract

Thoracic injury to elderly occupants in motor vehicle crashes is a serious concern. If these injuries to elderly occupants are to be reduced, several things need to be considered: 1) How is crash severity (Delta V) related to serious thoracic injury of older occupants? 2) Are crash test dummies sensitive enough for use in estimating thoracic injury risk to older occupants? and 3) What are the injury measurements in advanced dummies related to injury risk for older occupants?

Analysis of National Automotive Sampling System Crashworthiness Data System (NASS CDS) cases was performed to study the relative risk of serious thoracic injury among younger and older males and females, examine the distribution of Delta V (velocity change) for older occupants with serious thoracic injury, and identify Delta V’s with the largest percentage of older occupant serious thoracic injury cases in frontal and side impacts. Cases of occupants in motor vehicle crashes were drawn from NASS CDS for vehicle model years 1997-2008 for side impacts (all seat positions) and for vehicle model years 1994-2008 for frontal impacts (front seat only). Age groups utilized for data analysis included 20-39 and 65+ for side impacts and 20-39 and 60+ for frontal impacts.

To evaluate sensitivity of current midsize male crash test dummies, certification-type pendulum impacts to the thorax of the Thor-NT and the WorldSID dummies were conducted at impact velocities between 1.0 and 6.5 m/s.

Age-adjusted injury risk curves for the WorldSID midsize male were generated based on data by Petitjean et al. (2009). Injury risk curves for the Thor-NT dummy are not yet available.

Results of the current study show that occupant gender has a negligible effect on injury vulnerability in side impacts, whereas in frontal impacts, gender appears to play a more important role than age. In recent model year vehicles, the distribution of Delta V for older occupants with serious thoracic injury was approximately 10 km/h lower than that for seriously injured younger occupants in side impacts, but they were similar among seriously injured older and younger occupants in frontal impacts. The rate of older female injury was 6.5 times higher than that for younger females in frontal impacts, warranting further research. In real-world side impacts, 70% of older occupants with serious thoracic injuries were in crashes with a Delta V of 26 +/- 10 km/h in the current data set. In real-world frontal impacts, 42% of older occupants with serious thoracic injuries were in crashes with a Delta V of 29 +/- 10 km/h in the current data set. The WorldSID and Thor-NT dummies demonstrate excellent sensitivity and could potentially be used for evaluating injury risk for elderly occupants in lower severity impact tests. Injury risk curves for the WorldSID dummy have been generated for 65 year old mid-sized male occupants, from which a risk level can be established for use in evaluating injury risk to older occupants in side impact.

Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv22/22ESV-000397.pdf

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Cited By (4)

Year	Entry
2013	Hong SW, Park W, Hong S. Thoracic injury characteristics of elderly drivers in real world car accidents. In: Proceedings of the 23rd International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 27-30, 2013; Seoul, South Korea.
2012	Ridella SA, Rupp JD, Poland K. Age‐related differences in AIS 3+ crash injury risk, types, causation and mechanisms. In: Proceedings of the 2012 International IRCOBI Conference on the Biomechanics of Injury. September 12-14, 2012; Dublin, Ireland.43-60.
2012	Donnelly BR, Moorhouse K. Optimized phasing of PMHS response curves for biofidelity targets. In: Proceedings of the 2012 International IRCOBI Conference on the Biomechanics of Injury. September 12-14, 2012; Dublin, Ireland.418.
2018	Albert DL. Biomechanical Responses of Human Surrogates Under Various Frontal Loading Conditions With an Emphasis on Thoracic Response and Injury Tolerance [PhD thesis]. Virginia Polytechnic Institute and State University; April 19, 2018.