SAE 2014 Commercial Vehicle Engineering Congress
Technical Session Schedule
Thursday, October 9
Lightweighting Commercial Vehicles for Improved Efficiency
(Session Code: CVLW)
Room 53 9:00 a.m.
The focus of this session is on the latest advances in manufacturing strategies, design and materials selection strategies to promote lighter weight, higher performing, fuel efficient vehicles without sacrificing safety or performance. Presentations will address the latest breakthroughs in materials and cutting-edge technology applications. Special emphasis will be on tangible, cost-effective strategies in lightweighting.
Organizers - Claus Daniels, Oak Ridge National Laboratory; Marc LeDuc, SAE International
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|Rational Strategies for Light-Weighting
When considering substituting a lighter material for a heavier material, complex technical issues interact with cost and cultural considerations to make it difficult to make rational light-weighting decisions. This presentation discusses some of the technical issues of light-weighting and attempts to develop a semi-quantitative model that considers cost and other concerns. Case studies are used to demonstrate both successful and unsuccessful light-weighting activities.
David Weiss, ECK Industries Inc.
|Potential Weight Saving in Buses Through Multi Material Approach
Vehicle light-weighting of late has gained a lot of importance across the automotive industry. With the developed nations like the U.S. setting stringent fuel economy targets of 54.5 mpg by 2025, the car industry’s R&D is taking light weighting to a whole new level, besides improving engine efficiency. The commercial vehicles on the other hand are also gradually catching up when it comes to using alternate material for weight reduction. This paper will discuss light-weighting in the context of buses though.
Anil Kumar Cherukuri, Ashok Leyland, Ltd.
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|Heavy Truck Cab Design Using Forged Composite Technology
Recent research has focused on the application of discontinuous carbon fiber/epoxy forging systems to the fabrication of heavy truck cab design. Heavy truck cab designs typically employ sheet metal construction methods but some designs have also employed SMC design approaches. The use of discontinuous carbon fiber/epoxy forging has been utilized to reduce fabrication times and parts integration dramatically. It has been shown that through the use of discontinuous carbon fiber/epoxy forging significantly different design approaches can be implemented and that these approaches are then able to provide substantially improved bending and compressive strength capabilities when compared with traditional sheet metal fabrication design techniques. Here we first describe the background to heavy truck cab design as well as recent developments in discontinuous carbon fiber forging of large structures. Examples of applications are provided. Typical results have been shown to reduce parts integration, lower weight, and reduce final product costs. In this paper, the benefits are shown to be transferable to truck cab design through vastly improved parts integration and significantly reduced vehicle weight. As a result, there are opportunities to provide trucking companies with a tractor that has lower operating and life-cycle costs. This paper provides an analysis of an example baseline cab which details typical construction materials, typical construction techniques, associated weights, manufacturing times, fabrication costs, and operating costs. In comparison, a corresponding illustration and analysis of a forged discontinuous carbon fiber/epoxy cab as well as two alternative designs are provided. The results from the analyses are presented comparing part numbers, weights, final finished part costs and operating costs.
Paolo Feraboli, Automobili Lamborghini Spa; Keith Friedman, Friedman Research Corporation
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|New Materials for High Temperature Exhaust Manifolds
There is a significant interest in improving the break thermal efficiency in the next generation diesel engines in combination with reduced weight to achieve improved freight efficiency. Increased exhaust gas temperatures are anticipated in these next generation high efficiency diesel engines. Traditionally, cast irons such as high Si-Mo cast iron have been used in exhaust manifold applications. However the strength, oxidation resistance, and creep resistance of cast iron may not be adequate for operation at the projected higher temperatures. Furthermore, the increased need to reduce vehicle weight necessitates the use of materials with improved high temperature capability but without any added cost or weight. Thus, new materials are needed for use in exhaust manifolds. An alternative to cast irons are cast, austenitic stainless steels that are protected by the formation of a chromia-scale. Although the creep properties of these alloys are excellent, they are weaker than cast irons at room temperatures. Thus thicker material sections may be needed to withstand the same stress levels, thus increasing the weight and cost of the exhaust manifolds. ORNL has developed two classes of castable, austenitic stainless steel compositions that form a protective alumina scale. Alumina-forming austenitic stainless steel alloys offer the potential for superior high-temperature oxidation and corrosion resistance compared to conventional stainless steels and Ni-base alloys which are protected by chromia-based surface oxides. This is due to the slower growth rate and greater stability of alumina, particularly in the presence of water vapor species encountered in the exhaust and in many industrial process and energy production environments. This talk will compare the oxidation resistance, creep, and thermal fatigue performance of several cast alloys that could be considered for the fabrication of high temperature capable exhaust gas manifolds.
* Research sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, Propulsion Materials Program (managed by J. Gibbs) and partially by the Technology Innovation Program, Oak Ridge National Laboratory.
G. Muralidharan, Oak Ridge National Laboratory