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Magnesium die-cast alloys are known to have a layered microstructure composed of: (1) An outer skin layer characterized by a refined microstructure that is relatively defect-free; and (2) A “core” (interior) layer with a coarser microstructure having a higher concentration of features such as porosity and externally solidified grains (ESGs). Because of the difference in microstructural features, it has been long suggested that removal of the surface layer by machining could result in reduced mechanical properties in tested tensile samples. To examine the influence of the skin layer on the mechanical properties, a series of round tensile bars of varying diameters were die-cast in a specially-designed mold using the AM60 Mg alloy. A select number of the samples were machined to different final diameters. Subsequently, all of the samples (as-cast as well as machined) were tested in tension.

This report is a comprehensive investigation into the use of resin transfer molded glass fiber reinforced plastics in a structural application. A pickup truck cab structure is an ideal application for plastic composites. The cab is designed to fit a production Ranger pickup truck and uses carryover frame and front end structure. The cab concept consists primarily of two molded pieces. This design demonstrates extensive parts integration and allows for low-cost tooling, along with automated assembly.

Creep-resistant magnesium alloys for automotive powertrain applications offer significant potential for vehicle weight reduction. In this study permanent mold casting, microstructure and creep behavior have been investigated for a series of ternary magnesium alloys (Mg-4Al-4X (X: Ca, Ce, La, Sr) wt%) and AXJ530 (Mg-5Al-3Ca-0.15Sr, wt%). A permanent mold was instrumented with twelve thermocouples and mold temperature was monitored during the casting process. Average mold temperature increased from 200°C to 400°C during a typical alloy casting series (fifteen to twenty castings). The cast microstructure for all alloys consists of primary α-Mg globular phase surrounded by eutectic structure which is composed of intermetallic(s) and α-Mg magnesium phases. The primary cell size of the AXJ530 increased from 18 to 24 μm with increasing mold temperature and a similar trend is expected for all alloys.

A material selection including a natural material is conducted using a Simplified Life Cycle Assessment (SLCA) according to SETAC within the framework of Ford's Design for Environment (DfE) process. The aim has been to check both, the environmental performance of a design option concerning a specific component and the feasibility of methodology. The result of the simplified LCA is the recommendation to substitute glass fibers by hemp fibers in a specific insulation. The methodology provides differentiated environmental information and seems to be feasible. However, a lot of LCA experience is necessary to be enabled to simplify LCA.

The application of SEA (Statistical Energy Analysis) to the sound package design for a convertible is presented. SEA modeling was used optimize the soft-top construction and the acoustic insulation in the top-stack area (where the soft-top is stored) which were shown to be important transmission paths for tire noise. Correlation between measurement data and predictions from the SEA model is presented and good agreement shown. It is concluded that SEA can be applied to determine the special sound package requirements for convertible vehicles.

For an automotive exhaust system, analytical evaluation of coatings, dual wall, multiwall, and blanket insulation methods indicated that the blanket insulation provided the best method for heat containment. An experimental vehicle was tested with and without a blanket insulation on the exhaust system over a demanding heat protection cycle. The exhaust gas, pipe wall, surrounding air, and adjacent component temperatures at 25 locations along the pipe are reported indicating reduced outer wall temperatures and good containment of the heat. A comparison of the heat lost through the exhaust system walls is presented.

The design and composition of heat shields is becoming a major factor in the design of future automobiles. The optimization of heat insulation materials is crucial in keeping size, mass, and cost to a minimum. The purpose of this paper is to describe the testing of four different fibrous insulating materials simulating 150,000 miles of the Underbody heat shielding that a light duty truck may experience. The materials were tested before and after the thermal durability experiment to show the degraded conduction performance of each sample.

The backlite molding squeak noise is caused by the stick-slip type of friction between the window molding and the body panel. To predict if the molding would squeak a finite element analysis technique which uses the nonlinear explicit code LS-DYNA3D has been developed. The three dimensional finite element simulation technique is based on the threshold displacement velocity spectrum and the relative movement of the window glass with respect to the body panel. Comparisons between FEA analysis and tests are also presented in this paper.

This paper presents the design and operation of a new stepped bore master cylinder (fast-fill) which also integrates the rear brake proportioning valves and brake failure warning device in one major assembly. This design optimizes weight, performance and package together with several unique design features. It incorporates a combination of a plastic reservoir, permanent mold aluminum body, steel pistons, and minaturized steel proportioning valves resulting in a significant weight and cost reduction versus equivalent hydraulic actuation systems.

Development of the 1984 Ford Escort thermoplastic bumper is reviewed. This bumper consists of an injection-molded facebar and backplate which are friction-welded together to form a box beam. This design provides the necessary stiffness and load-management capability to meet 5-mph bumper impacts without a metal reinforcement beam, thus providing substantial weight and cost benefits compared to alternative systems. In addition, benefits of bumper resiliency, corrosion resistance, styling freedom and component integration are obtained.

Composite materials present automotive designers with unique opportunities for reduction of weight and increased performance when applied to vehicle structures. In addition these materials, through large-scale part integration, may also enable cost effective low volume production of derivative vehicles likely to be desired in the future marketplace. The development and demonstration of rapid composite processing techniques which provide cost effective manufacture of such structures is a requirement for the exploitation of the technology. A key process currently being investigated is High Speed Resin Transfer Molding (HSRTM). In HSRTM resin is injected into a heated tool that contains a three dimensional glass preform in the net shape of the final part. At this time, fabrication of the preform itself appears to be the major barrier for near-term implementation of this process. Currently most preforming of complex three dimensional shapes has been done with a cut and place process.

Investigations of the non-flame oxidation of exhaust gas hydrocarbons and carbon monoxide are reported. These investigations cover basic studies of the relationship of temperature, oxygen, and residence time to oxidation rates with external, supplementary, exhaust gas heating. Reaction (oxidation) is then shown to be possible without supplementary heat in the test installation of a homogeneous reactor on one cylinder of a V-8 engine on an engine dynamometer. Vehicle tests were then conducted to determine the operational characteristics and oxidation performances of a series of multi-cylinder reactors mounted on 292-cubic-inch-displacement engines. Unique methods of air introduction and heat conservation are described. These reactors were capable of effectively decreasing exhaust concentrations of hydrocarbon and carbon monoxide while the vehicles were driven over a traffic route. Tests of two reactors designed especially for fast warm-up are reported.

Vehicle sound package serves two basic functions: general acoustic insulation and local problem treatment. The former is often done at the up-front phase of the vehicle development process, and the latter at the downstream phase when representative prototype hardware becomes available and specific noise problems are identified. This paper examines the goals and key tasks of practical SEA CAE applications in the two phases of the sound package development process. Topics on CAE model requirement, typical analysis applications, and ways to improve the effectiveness of SEA applications to compliment hardware testing are discussed.