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A new Blow-Molded Roll-Bond (BMRB) aluminum technology has been developed to produce a durable, light-weight, double-wall heat shield with high performance characteristics. The resulting heat shield product is known as an Airgap heat shield. Theoretical results indicate that radiation heat shields should be made from materials with low emissivity and designed to maintain low emissivity levels. Wind tunnel testing showed that Airgap heat shields provide adequate thermal protection and road test results verified the thermal performance and durability of these heat shields. This heat shield technology is currently being used for volume production on a minivan platform.

The implementation of aluminum in today’s automotive body panels is an engineering problem seeking resolution of conflicting objectives including structural integrity, manufacturability and cost. This paper utilizes the results of a computer modeling technique to show the effects of differing aluminum alloy properties on body panel characteristics including: stiffness, dent resistance, oil canning, draw-die overcrown, minimum thickness, cost and weight. Minimum cost aluminum alloy selection is shown to be sensitive to panel curvature, inner panel support, yield strength and draw-die overcrown limits. Two case studies are presented comparing 1100, 3004, 5182-SSF, 2036-T4 and 6010-T6 aluminum alloys for varying design configurations of a typical automotive hood.

The most effective time to optimize an automotive body panel is early in its development. A full size clay model is one of these initial stages. The computer program developed minimizes the panel thickness and still maintains corporate quality levels. Stiffness, dent resistance, oil canning, and springback are the corporate quality requirements considered in this analysis. The program also generates weight and cost ratios for alternate material comparisons. This technique will not only reduce cost and weight, but also help guarantee customer satisfaction.

Successful automotive weight reduction with high strength-to-weight ratio steels has caused re-evaluation of the basic structural design parameters. This paper introduces the new concept of “Kinetic Modulus” which describes the nature of materials in motion. Kinetic modulus is influenced by stress and strain amplitude, yield strength and the number of loading cycles. The scope of kinetic modulus encompasses: elastic, secant, dynamic and tangent moduli; each of which is a specific case of kinetic modulus at a particular condition. Theoretical and experimental results are presented to support this concept. They show that high strength steel has higher dynamic stiffness and improved vibration response in structures as compared to that of lower strength steel. Thus, high strength steel (“Stiff Steel”) can be used advantageously in stiffness controlled automotive structures to achieve greater weight reductions.

This paper introduces a new technique, developed at Chrysler Corporation, for analyzing forming strains induced in sheet metal stampings. This technique, designated as the Photoelastic Stamping Analysis, employs thin plastic, photoelastic coatings to visually illuminate the overall forming strain distributions and magnitudes, on the surface of formed parts. This is accomplished by modifying an established photoelastic coating technique, whereby, photoelastic strain measurement capabilities are extended from the elastic region to cover the total range of plastic deformation. This technique was developed to assist in resolving design and manufacturing problems related to developing materials for stamped sheet metal parts. Current formability tests are described, followed by the presentation and discussion of the Photoelastic Stamping Anaylsis.

The substantial development efforts made by the steel and aluminum industries have resulted in high strength-to-weight ratio materials that can be employed to achieve significant vehicle weight reduction. This total vehicle weight reduction is the sum of the initial weight savings attributable to lightweight material substitution and the iterative weight savings resulting from component weight interactions. The theoretical concept of vehicle interactive weight reduction was presented in a previous work. The present work reviews this theoretical concept and presents an experimental application: Charger XL, a lightweight materials development vehicle. Charger XL is 630 lb. (286 kg) lighter than its current, standard production counterpart. Lightweight materials substitution accounts for 375 lb (171 kg) while the interacting savings accounts for the remaining 255 lb (115 kg).

The use of aluminum in automobiles can significantly reduce vehicle weight. This paper discusses factors that relate to why aluminum will be used in automobiles. These factors are fuel economy, fuel cost, federal regulations, and increasing weight trends. The cost of reducing weight is analyzed by the overall economy concept. Overall economy includes operating cost and initial purchase price. The role of inertia weight class and interacting weight reduction are discussed and exemplified by two vehicles. One is a production vehicle, the Feather Duster and the other is a prototype called the Charger XL. The substitution of aluminum into conventional applications sometimes requires the developing of new technology in design and manufacturing. These aspects of how aluminum will be used in automobiles is also discussed.