Review of the EURO NCAP Upper Leg Test

• The EEVC WG17 upper leg test as used in EuroNCAP was reviewed. Previous work revealedshortcomings of the EEVC WG17 test set-up.Recent published accident data show that injuriesto the lower extremities by the bonnet leading edge,not including ground impacts, only accounted for5% of all AIS2+ injuries and 4% of all AIS3+injuries. Previous work and this data indicate adiscrepancy in importance of the upper leg testbetween Euro NCAP and real-life injuryfrequencies.Suggested legform impactor threshold values haveso far not been based on human injury risktransferred to impactor values. The implications ofthe proposed improvements to the test set-up fromSnedeker et al. (2005) for Euro NCAP test resultshave not been assessed. Both the above issues areaimed at in this study. They are important as onlywith the right targets and evaluation methods,traffic related injuries can be minimized.Human injury threshold values for femur and pelvisimpact were derived from applicable and originalPMHS data. Data was scaled to a mid-sized male,survival analysis with Weibull fit was performedwith exact femur 3-point bending data, logisticregression with doubly censored pelvis impact data.Legform thresholds were derived using a linearregression between impactor and THUMS valuesderived form tests conducted by Snedeker et al.(2005). It is assumed that THUMS and upper legsurrogates have a similar response. Theimplications of the new set-up and thresholds forEuro NCAP test results were assessed for resultspublished 2009 and 2010 using empiricalrelationships between impact energy, measuredforce and moment.Using this approach, the resulting thresholds to beused with the legform were determined to be 7.9-9.0 kN for the pelvis test and 300-365 Nm for thefemur test. These values correspond to 5 and 20%fracture risk, respectively.With the currently used set-up and limits, theaverage score for the upper leg test is 22% of themaximum score. With the proposed method andlimits, the average score calculated is 70%. Withonly 30% missing, the score matches better withthe accident frequency of bonnet leading edgeinduced injuries to lower extremities.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Annan materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Other Materials Engineering (hsv//eng)

Nyckelord

Upper Leg Test

EURO-NCAP

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