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Advanced high-strength steels (AHSS) are a family of steels that are stronger than most steels and have better formability than today’s conventional high-strength steels. New U.S. safety and fuel economy regulations have intensified pressure on OEMs to reduce vehicle weight. These pressures are causing auto companies to rethink alternative material applications and to look for opportunities that steel offers. The purpose of this book is to provide information for engineers who are designing the next generation of lighter vehicles. The material in the book is presented to help them make informed decisions on what basic materials to use and how to optimize those materials to achieve cost-effective weight reduction. The emphasis is on steels in general and AHSS in particular. However, there is much information on comparisons of steel with alternative materials for different subsystems of the vehicle.

This paper describes a joint project between Ford, the American Iron & Steel Institute, the University of Louisville, and the U. S. Army to reduce the weight of a full size pick-up truck by 25%, while keeping incremental costs to a minimum. Several alternate technologies were evaluated for each system, subsystem, and component of the vehicle and based on analysis of all combinations of these technologies, the solution which yielded the best overall cost and weight balance, while meeting all of the functional requirements, was selected. The major focus of the project was to develop new steel architectures and materials, since this would assure the maintenance of the lowest possible cost, though the study was not restricted to steel alone. The project was successful in meeting all of its targets, and a vehicle was built to demonstrate the feasibility of the various concepts.

Impact strength of pickup box floor panels is determined using a test called “The Drum Drop Test”. This drum drop test is one of the key verification requirements in the design of the pickup box floor panels. Non-linear CAE analysis is done in order to assess the performance of the pickup box design for this requirement. In this paper, a sensitivity study of various parameters that affect the performance of the pickup box floor panels is presented. Critical parameters are identified which would drive the design of the floor panels. This paper also highlights the weight reduction opportunity by using high strength steels for the design of floor panels.

Advanced High Strength Steels such as Dual Phase 600 (DP600) are gaining popularity in automotive body structure applications. Given their higher strength, the efficacy of Advanced High Strength Steels for intrusion resistance applications is relatively well accepted. On the other hand, use of Advanced High Strength Steels for energy absorption applications needs to be studied and understood on a case-by-case basis. Based on stress-strain characteristics, one would expect DP600 as a material to have better energy absorbing characteristics than conventional High Strength Steel such as HSLA350 (High Strength Low Alloy Steel) that has comparable yield strength. However, as the energy absorption at the component and system level, in addition to material properties, depends on geometry, as well as manufacturing and assembly related factors, a study was conducted to compare the component level energy absorption characteristics of DP600 and HSLA350 parts.

Squeak and rattle is one of the major concerns in vehicle design for customer satisfaction. Traditionally, squeak and rattle problems are found and fixed at a very late design stage due to lack of up-front CAE prevention and prediction tools. An earlier research work conducted at Ford reveals a correlation between the vehicle overall squeak and rattle performance and the diagonal distortions of body closure openings under a static torsional load. This finding makes it possible to assess squeak and rattle performance implications between different body designs using body-in-prime (B-I-P) and vehicle low frequency noise vibration and harshness (NVH) CAE models at a very early design stage. This paper presents an application of this squeak and rattle assessment method for a design feasibility study concerning a cab structure of a super duty truck for weight reduction using high strength steel and adhesive bonding.

This paper reports on the efforts of the initial phase of the IMPACT program to define the underlying structural theory behind selecting the proper material(s) to reduce weight in the most efficient, cost-effective manner. Following this initial phase, the IMPACT program will proceed to design and build, optimized, proprietary, full vehicle platform prototypes that achieve up to a 25 percent weight reduction total without compromising any customer-driven vehicle attributes. Most importantly, the materials and technologies selected must be implementation ready for high volume, low cost, dual-use applications. The purpose of the initial phase and an in-depth discussion on which material properties should most influence material selection are presented.