Search Results

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.

This SAE Recommended. Practice provides uniform laboratory procedures for fatigue testing certain production disc wheels, spoke wheels, and demountable rims intended for normal highway use on trucks, buses, truck-trailers, and multipurpose passenger vehicles. Standardized fatigue tests are yet to be developed for wheels/rims not covered in this recommended practice.

This SAE Recommended Practice provides uniform laboratory procedures for fatigue testing certain production disc wheels, and demountable rims intended for normal highway use on trucks, buses, truck-trailers, and multipurpose passenger vehicles. This document does not cover bolt together divided wheels or other special application wheels and rims.

This SAE Recommended Practice provides uniform laboratory procedures for fatigue testing certain production disc wheels, wheels for demountable rims, and demountable rims intended for normal highway use on trucks, buses, truck-trailers, and multipurpose passenger vehicles. Standardized fatigue tests are yet to be developed for wheels and rims not covered in this recommended practice.

This SAE Recommended Practice includes wheel mounting elements subject to standardization in a series of industrial and agricultural disc wheels. The disc may be reversible or nonreversible and concave or convex. (See Figure 1 and Table 1.)

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.

This SAE Recommended Practice provides the following for the windshield washer system for trucks, buses, and multipurpose vehicles with GVW of 4500 kg (10 000 lb) or greater: a Minimum performance requirement b Uniform test procedures. The test procedures are limited to those tests that can be conducted with uniform test equipment by commercially available laboratory facilities. c Uniform terminology of windshield washer system characteristics and phenomena. The minimum performance requirements and test procedures, outlined in this document, are based on currently available engineering data. It is intended that all portions of the document will be periodically reviewed and revised as additional data on windshield washer system performance are developed.

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.

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.

We present standardized test results indicating that ToughMet® copper-nickel-tin alloy will outlast traditional transmission thrust bearing materials without increasing frictional power loss or endangering mating components. Sleeve bearing tests show the PV (bearing pressure × linear speed) limit of ToughMet is more than three times that of leaded tin bronze. In thrust washer wear rate testing ToughMet provided 4 and 14 times reduction in wear rate as compared to leaded tin bronze at speeds and pressures found in transmissions. The performance advantage is related to differences in physical and mechanical properties between the two materials.