Development of a Detailed Vehicle Finite Element Model Part I: Methodology

Abstract on September 29, 1993, President Clinton and the Chief Executive Officers of the major domestic automakers (Chrysler Corporation, Ford Motor Company, and General Motors Corporation) announced the formation of the Partnership for a New Generation of Vehicles (PNGV). The long-term goal of PNGV is to develop vehicles that will deliver up to three times today's fuel efficiency (80 miles per gallon or BTU equivalent) and cost no more to own and operate than today's comparable vehicles. At the same time, this new generation of vehicles should maintain the size, utility and performance standards of today's vehicles (i.e., the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina) and meet all mandated safety and emission requirements [1,2]. As part of the PNGV program, The National Highway Traffic Safety Administration (NHTSA) intends on developing a vehicle finite element model representing each vehicle class and size. These FE models will be used in compatibility studies to ensure that PNGV vehicles meet safety standards and that crashworthiness and crash avoidance attributes are not compromised by their lightweight and use of advanced materials. A detailed finite element model of a 1996 Plymouth Neon was developed at the FHWA/NHTSA National Crash Analysis Center as part of the PNGV program. The Neon represents the sub-compact vehicle class. The three dimensional geometric data of each component was obtained by using a passive digitising arm. The geometric data was imported into a preprocessor for mesh generation, parts connection, and material properties. Tensile testing was conducted on specimen to obtain the material properties of the various sheet metal components. Sheet metal thickness was obtained by using an ultrasonic thickness measurement gauge. The non-linear explicit finite element code LS-DYNA, was used to perform the various simulations. This paper will conclude on the following issues; describing and efficient methodology for reverse engineering vehicles; importance of maintaining geometric accuracy; issues concerning material characterization; significance and necessity of component wise testing.