This content is not included in your SAE MOBILUS subscription, or you are not logged in.
The New Car Assessment Program Has It Led to Stiffer Light Trucks and Vans over the Years?
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 01, 1999 by SAE International in United States
Annotation ability available
Since model year 1983, one hundred and seventy five light trucks, vans, and sport utility vehicles (LTVs) have been included in the New Car Assessment Program (NCAP) frontal crash tests. In this frontal test, vehicles are crashed at 35 mph such that the entire front impacts against a rigid, fixed barrier. Instrumented anthropometric dummies are placed in the driver and right front passenger seats. Accelerometers are placed on the vehicle to record the response of the structure during the crash.
A number of recent papers have examined the compatibility of LTVs and cars in vehicle-to-vehicle collisions. The studies in these papers, generally, consider three factors for vehicle-to-vehicle compatibility: (1) mass, (2) stiffness, and (3) geometry. On June 5, 1998, Transport Canada and the National Highway Traffic Safety Administration held a forum entitled “Transport-NHTSA International Dialogue on Vehicle Compatibility,” in Windsor, Canada. At the forum, representatives of major vehicle manufacturers expressed the view that NCAP has led to the design of more aggressive stiffness parameters for LTV front structures. With crash data on 175 LTVs distributed over the last 15 model years, it is possible to examine and analyze the actual trends of the stiffness and structural characteristics of this class of vehicles. In this paper, the acceleration data from accelerometers in the occupant compartment and from the dummies are analyzed to determine:
- 1the trend of total stiffness or aggressivity characteristics of LTVs since MY 1983,
- 2the trend of the approximate linear stiffness of LTVs during the first 200 mm of crush since MY 1983, and
- 3the effect of these structural characteristics on the NCAP safety ratings.
Three parameters, that are associated with energy management and with the crushing of the front structure (the crash signature of crash pulse) of the vehicle, are studied relative to the total stiffness or aggressivity of LTVs. These three parameters are (1) maximum dynamic crush, (2) maximum acceleration of the vehicle structure, and (3) the time period of the acceleration pulse. Approximate linear stiffness values are calculated from the occupant compartment accelerations and the vehicle masses for the first 200 mm of vehicle crush during the rigid barrier impact. The stiffness of these first 200 mm is an approximate measure of the structural aggressivity of the striking vehicle in front to side impacts. The effect of these aggressivity and stiffness parameters on the dummy responses is examined. It is shown that, on the average,
- 1the maximum dynamic crush and the time period of the acceleration pulse have increased over time. The maximum acceleration of the vehicle structure has decreased over time.
- 2the approximate linear stiffness in the first 200 mm of crush has decreased over time, and
- 3there is a correlation between lower stiffness and aggressivity parameters and better NCAP scores.
These findings indicate that NCAP may have influenced manufacturers to design less aggressive, and, therefore, more compatible LTV front structures for both front to front and front to side impacts.
|Technical Paper||Sled Testing Procedure for Side Impact Airbag Development|
|Technical Paper||Injury and Response of the Thorax in Side Impact Cadaveric Tests|
|Technical Paper||Comparison of Frontal Crashes in Terms of Average Acceleration|
- Brian T. Park - National Highway Traffic Safety Administration
- James R. Hackney - National Highway Traffic Safety Administration
- Richard M. Morgan - National Highway Traffic Safety Administration
- Hansun Chan - National Highway Traffic Safety Administration
- Johanna C. Lowrie - ALCOSYS, Inc.
- Heather E. Devlin - ALCOSYS, Inc.
CitationPark, B., Hackney, J., Morgan, R., Chan, H. et al., "The New Car Assessment Program Has It Led to Stiffer Light Trucks and Vans over the Years?," SAE Technical Paper 1999-01-0064, 1999, https://doi.org/10.4271/1999-01-0064.
Vehicle Aggressivity and Compatibility in Automotive Crashes
Number: SP-1442; Published: 1999-03-01
Number: SP-1442; Published: 1999-03-01
- Hackney, J. R. “The Effects of FMVSS No. 208 and NCAP on Safety as Determined from Crash Test Results,” Proceedings of the Thirteenth International Conference on Experimental Safety Vehicles Paris, France November 1991
- Prasad, P. Mertz, H. “The Position of the United States Delegation to the ISO Working Group 6 on the Use of HIC in the Automotive Environment,” SAE Paper 851246 , presented at the SAE Government/Industry Meeting and Exposition Washington, DC May 1985
- Viano, D. C. Arepally, S. “Assessing the Safety Performance of Occupant Restraint Systems,” Proceedings of the 34th Stapp Car Crash Conference, SAE Paper 902328 Warrendale, PA November 1990
- Traffic Safety Facts 1996 National Highway Traffic Safety Administration, U.S. Department of Transportation, Report No. DOT HS 808 649 17 December 1997
- Shopping for Safety: Providing Consumer Automotive Safety Information Transportation Research Board, National Research Council, Special Report 248 National Academy Press Washington, DC 1996
- GAO Highway Safety: Reliability and Validity of DOT Crash Tests GAO/PEMD-95-5 May 1995
- Kahane, C. J. Hackney, J. R. Berkowitz, A. M.. Correlation of NCAP Performance with Fatality Risk in Actual Head-On Collisions Report No. DOT HS 808 061, National Highway Traffic Safety Administration Washington, DC 1994
- Hackney, J. R. Kahane, C. J. “The New Car Assessment Program: Five Star Rating System and Vehicle Safety Performance Characteristics,” SAE Paper 950888 , presented at the SAE International Congress and Exposition Detroit, Michigan February 1995
- Hollowell, W. T. Gabler, H. C. “NHTSA's Vehicle Agressivity and Compatibility Research Program,” Proceedings of the Fifteenth International Enhanced Safety Vehicle Conference Melbourne, Australia 1996
- Hollowell, W. T. Gabler, H. C. “The Aggressivity of Light Trucks and Vans in Traffic Crashes,” SAE Paper No. 980908 , SAE International Congress & Exposition Detroit, Michigan February 1998
- Insurance Institute for Highway Safety “Status Report on Crash Compatibility,” Arlington, VA 33 1 February 14 1998
- Faerber, E. Cesari, D. Hobbs, A. C. Huibers, J. van Kampen, B. Paez, J. Wykes, N. J. “Improvement of Crash Compatibility Between Cars,” Proceedings of the Sixteenth International Enhanced Safety Vehicle Conference Windsor, Canada June 1998
- Schoenburg, R. Pankalla, H. “Implementaion and Assessment of Measures for Compatible Crash Behavior using the Aluminum Vehicle as an Example,” Proceedings of the Sixteenth International Enhanced Safety Vehicle Conference Windsor, Canada June 1998