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Cyclic oligomers of butylene terephthalate (CBT™)† represent a new chemical route to semi-crystalline thermoplastic polybutylene terephthalate (PBT). The oligomers of interest melt completely at about 150°C to produce a low viscosity fluid that is ideal for wetting and dispersing fibrous fillers and reinforcements thereby enabling the development of composites that were previously not possible when working with high viscosity commercial PBT. Introduction of catalyst to undiluted molten cyclic oligomer leads to rapid ring opening polymerization and the formation of high molecular weight thermoplastic PBT without the generation of volatile organic compounds. The polymer resulting from this polymerization will be hereby referred to as pCBT. Treatment of cyclic oligomers in this fashion results in pCBT thermoplastic resin with a high melting point (230°C) and physical performance similar to that of other commercially available PBT resins.

Welding has been used extensively in automotive components design due to its flexibility to be applied in manufacturing, high structural strength and low cost. To improve fuel economy and reduce material cost, weight reduction by optimized structural design has been a high priority in auto industry. In the majority of heavy duty vehicle's chassis components design, the ability to predict the mechanical performance of welded joints is the key to success of structural optimization. FEA (finite element analysis) has been used in the industry to analyze welded parts. However, mesh sensitivity and material properties have been major issues due to geometry irregularity, metallurgical degradation of the base material, and inherent residual stress associated with welded joints. An approach, equilibrium-equivalent structural stress method, led by Battelle and through several joint industrial projects (JIP), has been developed.

Wear characteristics of four bearing materials have been investigated under different sliding conditions. The bearing materials used were CDA 954, CDA 863, CDA 932, and CDA 938. Using a Taber Wear Tester, a cylinder on a flat geometry was used as a tribo contact pair. All bearing materials in the form of a thick cylindrical disk were subjected to combined sliding-rolling motion against a rotating flat disk. The flat disk was either an abrasive disk, or a very soft steel disk, or a hardened steel disk with and without lubrication. Wear was measured as weight loss after several thousand cycles of rotation. Maximum wear of the bearing materials occurred when the counter body was a very soft steel disk. These results together with the wear rate of each bearing material sliding against four different counter bodies are presented. These results are found to be of practical importance in the design and application of journal bearings made of materials used in this investigation.

The existing instrumentation of a soil bin was retrofitted with virtual instrumentation techniques to achieve improved repeatability and more precise measurements. Current-loop sensors were added to the prime mover for improved speed control. Soil preparation operations were instrumented to determine penetrometer forces as a function of soil penetration depth, soil surface smoothness, compaction force, and soil surface elevation. Test hitch-points for agricultural implements were instrumented with wheatstone bridge force transducers. Implement depth was found with ratiometric linear transducers. Distance and speed determinations utilized an optical encoder with a resolution of 3.0 × 10-4 m. Temperature measurements were also recorded with solid state current transducers.

This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.

Outboard Marine Corporation (OMC) developed its own vacuum die casting process to produce true T6 heat treatable aluminum die castings. This process was initiated by OMC Research and developed jointly with OMC Waukegan. The project began 1990 and was put into production in 1992 on the outboard motor lower mount bracket shown in figure 1. OMC is producing vacuum die cast aluminum parts made with 356.0 alloy and T6 heat treated which meet or exceed the strength of similarly alloyed and processed permanent mold or lost foam cast parts. The application of this process is being expanded within the realm of structural outboard motor parts to include other mounting brackets, as well as fuel system components. An automotive die caster is using the technology and equipment provided by OMC to produce leak tight air conditioner compressor housings.

Several methods have been developed which use rapid prototyping techniques to assist in the creation of prototype metal castings. Methods exist for a number of casting processes such as sand casting, die casting, investment casting, and evaporative pattern casting. In many cases, these methods can reduce both the time and cost required to create prototype castings.

The conceptualization, design, analysis, prototyping, and testing of a steel casting are described. The methods used include 2D CAD, 3D solid modeling, finite element analysis, Solid Ground Curing rapid prototyping, and laboratory prototype testing. The part was successfully delivered to field testing on time. The use of the MCAE techniques provided a more optimal part more quickly than the use of standard CAD techniques would have provided. A minor cost penalty was paid for the prototype pattern versus conventional prototyping.

A new 12.5 L four-valve heavy duty diesel engine has demonstrated that Powdered Metal (PM) is an effective material alternative to wrought steel for the valve bridge. The valve bridge, an element that spans the pair of intake or exhaust valves, allows a single rocker arm to actuate the pair of valves. The component is subjected to a high number of cycles at a moderately high load and geometry precision is essential for desirable wear characteristics. The PM material selected, MPIF FL4605-120HT, has replaced 8620 steel after making component geometry changes. The PM part has a higher load capacity than the original design with equivalent wear characteristics and offers a 80% cost saving over the original design. This paper presents the geometry changes defined by FEA analysis and component testing performed to verify the change from wrought steel to PM. A required characteristic of this component is moderately high fatigue strength.

In keeping with the Department of Energy's mission of national energy conservation and environmental preservation, higher combustor operating temperatures are required. The DOE's strategy envisions gas turbines with improved performance, lower emissions, and greater temperature durability. The high temperature properties of continuous fiber reinforced ceramic composites make them ideal for combustor applications. Potential has been demonstrated in endurance tests on composite subscale combustor liners.

Sliding wear tests were conducted with silicon nitride (Si3N4) against five retainer materials using different lubricants. The sliding wear tests were conducted with the Torrington Tribology tester at three normal loads and one sliding speed at an ambient lubricant oil temperature and one hour duration. The retainer materials were polyetheretherketone (PEEK) with glass fill, PEEK with carbon graphite/PTFE (polytetrafluoroethylene) fill, machined aluminum with a WS2 coating, machined steel with a silver plating, and machined bronze. The Si3N4 ceramic specimens (both NBD-100 and NBD-200) did not experience any measurable or observable wear. Friction coefficients varied between 0.03 and 0.16 depending upon the retainer material and the lubricant; the lowest values were obtained with the PEEK materials. Large wear scars were generated on the machined bronze, along with high friction coefficients and slip-stick behavior.

E-spring is an optimized trend of springs for vehicle suspension systems. Experimental and transmissibility analyses of laminated fibrous composite E-springs are conducted. The mechanical and frequency-response-based properties of these springs are investigated experimentally at both of the structural and constitutional levels. Thermoplastic-based and thermoset-based fibrous composite structures of the E-springs are modified at micro-scale with various additives and consequently they are compared. The experimental results reveal that additives of micrometer-sized particles of E-glass fibers as well as mineral clay to an ISO-phthalic polyester resin of the composite E-spring can demonstrate superior characteristics. The transmissibility analysis of laminated fibrous composite E-springs reveals superior frequency ratio.

Agricultural tractor work rate depends on tire tractive performance, and crop growth depends on soil degree of compaction. The concept of tire footprint efficiency ratio, based on tire footprint and mean ground pressure studies, is introduced to evaluate tire performance. Effects of mean ground pressure on soil degree of compaction and relative crop yield are presented. A method is proposed to compare various tire mount alternatives, with respect to tractive performance and crop revenue. A sample tire equipment comparison scheme is presented.

Designed to support the need of engineering, management, and other professionals for information on titanium by providing an overview of the major topics, Titanium: A Technical Guide provides a concise summary of the most useful information required to understanding titanium and its alloys. The author provides a review of the significant features of the metallurgy and application of titanium and its alloys. All technical aspects of the use of titanium are covered, with sufficient metals property data for most users.

Past tillage practices in the Corn belt were primarily based on the moldboard plow. The chisel plow, disk, and other forms of reduced tillage are now used extensively. The trend toward less tillage has occurred from the desire to reduce costs and to utilize plant residue to control erosion. The trend is hampered by the goal to maintain consistent high yield levels. Yields often decrease due to soil compaction, inadequate weed control, insufficient nutrient incorporation, and other factors. New tillage practices will be tried by farmers but before being widely adopted will be critically evaluated economically and for effects on erosion.

Polypropylene is typically reinforced with commodities that are non renewable and require a great deal of energy to produce. The marketplace needs a reinforcement that can offer beneficial physical properties, such as impact, while being attained from a renewable green source. Compounding flax fiber, which is traditionally an agricultural waste product burned by farmers, with polypropylene yields physical properties similar to traditional glass filled polypropylene. This combination should lead to cost saving opportunities while not sacrificing part performance. Presenter James Preston, Rhetech Inc.

Recently high heat resistant friction materials containing synthetic fibers have been developed to meet the requirements from heavy-duty vehicle manufactures. However, traditional cut in groove process (hereafter, CIG process) cannot cut grooves on these materials clearly. Projection near groove and fuzz inside of groove exist after the CIG process. The projection and fuzz are generally considered the reason of high drag torque during idling [1]. But very little information was provided to deal with the projection and fuzz and how to reduce the drag torque caused by projection and fuzz. In this paper, various processes will be discussed to reduce drag torque and an optimized groove specification will also be proposed for high heat resistant friction materials for heavy-duty vehicles.

This paper discusses steels and heat treatments that have and are being used in John Deere tractors. Some of the development test work is described which led to a given selection in three specific cases. Stress levels and other tractor gear design factors are mentioned.