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A study was conducted to identify customer requests of power window sound quality and the primary factors that contribute to customer perception and preference of power window sound. Sound samples recorded from current production vehicles were evaluated by a jury panel on perceived sound quality using a semantic differential scale. Forty-eight subjects participated in this study. Factor Analysis results of the ratings found three factors: intensity, pitch variation and sharpness. Variables in the intensity factor correlated well to overall preference of the sound, while pitch variation and sharpness were secondary in contributing to the overall perception of power window sound quality. Further analysis correlated subjective preference ratings to psychoacoustic measures to develop a rating index for window regulator sound quality assessment.

The 29 papers in this technical paper collection cover topics such as spot welding of advanced high strength steels, weldability improvement, metal inert gas welding process optimization, self-piercing riveting, stir spot welding, and more.

METHODS employed by the author to reduce the weight of the structural frame without sacrificing strength are described in the paper. To obtain this result the best available cross-section must be selected and the members arranged to transmit the load directly to the final supports which should lie approximately in a plane that is parallel to the load vector; also where a bending moment is caused by the loading, the support attachment should produce a moment of the same amount and of opposite sign. Avoiding secondary bending and utilizing the advantages of full continuity over supports can be secured by a simple arrangement of the frame members. Substitution of power tools for hand tools will effect a reduction in assembly costs. Sections suitable for power assembly include closed hollow-sections, which have a high structural efficiency, as well as angles, channels, I-beams and similar shapes.

The objective of this work is analyze the weight influence in super economic vehicle rolling resistance tyre for low velocity. One of the principal factors in fuel consume is the rolling resistance, once, in low velocity the aerodynamic drag is not very pronunciation. The rolling resistance analysis was made using a rolling belt instrumented with velocity between 1.5 km/h and 9 km/h) and weight between 0 (zero) and 300 N. The analysis results, permits an equation elaboration, relationship weight and velocity for one tyre rigidity.

Wedgerolling is a relatively new hot metal forming process that combines the techniques and advantages of forging, hot extruding, screw machining or chucking, into one automatic process for round bar, billets or heavy wall tube. Wedgerolling or transverse hot roll forming as we know it today was really perfected and put to actual production use in the late 1950's, originally in Czechoslovakia. It is now used in Russia and in England. It offers both advantages and disadvantages over currently used metal shaping and metal removal processes. It reduces diameters of material, does not intentionally gather like cold heading. Depending upon the particular part applications, it can offer up to 400% in cost savings over popular processes now in production use.

This SAE Recommended Practice specifies a dynamometer test procedure to be used for the measurement of automotive service brake linings and disc brake pads wear.

This SAE Recommended Practice specifies a dynamometer test procedure to be used for the measurement of automotive service brake linings and disc brake pads wear.

The wear test introduced in this paper can be used to determine and rank PV (pressure time velocity) capability of plastic materials for applications where a plastic part is rotating or reciprocating against a metal surface. It provides an accelerated test method to evaluate the wear performance of plastic materials. A single test can provide tribological information at multiple PV conditions. The tribological information obtained from this method includes coefficient of friction, PV (pressure times velocity) limits, and interface temperature profile. This test is currently used by General Motors Corporation to develop plastic materials for transmission thrust washer and dynamic seal applications. The test is running in two sequences (A & B), capable of a PV range from 50,000 psi-ft/min 500,000 psi-ft/min, under dry conditions. The PV steps in sequence A are combinations of high pressure and low velocity - for applications where high loads are expected, such as thrust washers.

The purpose of this research is to characterize the wear resistance of wheel treads made of polymeric woven and non-woven fabrics. Experimental research is used to characterize two wear mechanisms: (1) external wear due to large sliding between the tread and rocks, and (2) external wear due to small sliding between the tread and abrasive sand. Experimental setups include an abrasion tester and a small-scale merry-go-round where the tread is attached to a deformable rolling wheel. The wear resistance is characterized using various measures including, quantitatively, by the number of cycles to failure, and qualitatively, by micro-visual inspection of the fibers’ surface. This paper describes the issues related to each experiment and discusses the results obtained with different polymeric materials, fabric densities and sizes. The predominant wear mechanism is identified and should then be used as one of the criteria for further design of the tread.

Austempered cast irons have a unique microstructure (ausferrite) that provides for excellent wear properties. This paper will examine the available data in the literature on wear in several modes: abrasive wear, adhesive wear (frictional or sliding and rolling), and erosive wear. Additional wear data, including that from competitive materials as well as from private communications, will be presented along with examples of applications of austempered ductile cast irons where wear properties are of concern

Previous tribology studies on ultra-performance engineering polymers, which include polyetheretherketone, (PEEK), polyamideimide (PAI), and polyimide (PI), have focused on pressure and velocity (PV) conditions lower than those typically seen in automotive transmissions. Thrust washers, seal rings and bearings typically endure severe PV conditions. Although this environment is normally lubricated, actual lubrication conditions can vary and the best polymeric materials will be able to handle a loss of lubrication without failure. This study investigated the ultra-performance class of engineering polymers at high PV conditions (50,000-100,000 ft-lb/in2min), under high velocities (up to 800 ft/min), using the ASTM D 3702 thrust washer test specimen rotating against C1018 steel. Tests were done without external lubrication in order to evaluate the performance of the polymer compounds under extreme conditions.

Porous wall permeability is one of the most critical factors for the estimation of backpressure, a key performance indicator in automotive particulate filters. Current experimental and analytical filter models could be calibrated to predict the permeability of a specific filter. However, they fail to provide a reliable estimation for the dependence of the permeability on key parameters such as wall porosity and pore size. This study presents a novel methodology for experimentally determining the permeability of filter walls. The results from four substrates with different porosities and pore sizes are compared with several popular permeability estimation methods (experimental and analytical), and their validity for this application is assessed. It is shown that none of the assessed methods predict all permeability trends for all substrates, for cold or hot flow, indicating that other wall properties besides porosity and pore size are important.

Previous research on both small-scale and full-scale vehicles shows that base extensions are an effective method to increase the base pressure, enhancing pressure recovery and reducing the wake size. These extensions decrease drag at zero yaw, but show an even larger improvement at small yaw angles. In this paper, rear extensions are investigated on an SUV in the Volvo Cars Aerodynamic Wind Tunnel with focus on the wake flow and on the unsteady behavior of the surface pressures near the base perimeter. To increase the effect of the extensions on the wake flow, the investigated configurations have a closed upper- and lower grille (closed-cooling) and the underbody has been smoothed with additional panels. This paper aims to analyze differences in flow characteristics on the wake of an SUV at 0° and 2.5° yaw, caused by different sets of extensions attached to the base perimeter. Extensions with several lengths are investigated with and without a kick.

The early wheels merely rolled, carried weight and resisted side strains; later they were called upon to transmit braking forces and still later the driving force. Prior to the automobile, wire wheels were not called upon to support much weight and the usual type was that used for bicycles. When automobiles were first built, bicycle-type wire-wheels were employed and used until the demand for larger wheels presented unsurmountable obstacles. From that time a development was in progress in this country and in England that resulted in the triple-spoke wire-wheel which has grown in popularity since 1912. The different types of wheels are discussed and the advantages and disadvantages of wire wheels stated; three diagrams are shown. As the wire wheel is a “suspension” wheel, the car weight is hung or “cradled” from scores of resilient, flexible spokes, and the pull is always on three-quarters of the spokes.

This SAE Recommended Practice provides uniform procedures for fatigue testing ferrous wheels intended for normal highway use on travel, camping, boat and light utility trailers drawn by passenger cars and light trucks. For performance requirements, see SAE Jxxx. For procedures and minimum performance requirements for truck-type rims and wheels, see SAE J267a and for passenger car rims and wheels see SAE J328a. Mobile home service is also outside the scope of this recommended practice. There are two basic test procedures described, a cornering fatigue test and a radial fatigue test. The cornering test is directed at the wheel portion of the wheel/rim assembly; whereas the radial test will examine potential deficiencies in the rim portion of the structure. Both test procedures are required to obtain a thorough examination of the wheel/rim assembly.

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 document provides uniform procedures and minimum performance requirements for fatigue testing pressed steel wheels intended for normal highway use on travel, camping, and boat and light utility trailers drawn by passenger cars and light trucks. For procedures and minimum performance requirements for wheels used on trucks, see SAE J267, and for wheels used on passenger cars, see SAE J328. For the application of passenger car and light truck wheels [inset less than 0.33 ft (0.10 m)] to this trailer service, use this procedure. For the application of heavier truck wheels [inset 0.33 ft (0.10 m) or more] use SAE J267. Mobile home service is outside the scope of this document. There are two basic test procedures described, a cornering fatigue test and radial fatigue test. The cornering test is directed at the wheel disc; whereas the radial test also examines the rim and attachment portion of the wheel. Both test procedures are required to obtain a thorough examination of the wheel.

Shimmying is an oscillating motion produced by repeated impacts or forces in the linkage of a mechanism that lacks stability or has become loose because of wear. Although previously existent in chassis in which the steering-gear was imperfect, it has become particularly noticeable since the introduction of low-pressure or balloon tires. But increasing the rigidity means increasing the unsprung weight, which, in turn, means greater impacts, hence, more shimmying. This is apparent in the effect produced by front-wheel brakes. Consequently, as the amount of looseness that can be removed is limited, the periodic forces that cause shimmying must be overcome.

This SAE Recommended Practice provides minimum performance requirements and uniform procedures for nut seat system strength of wheels intended for normal highway use on passenger cars, light trucks, (except dual wheels, which are covered by SAE J1965) and multipurpose passenger vehicles. The nut seat system includes the wheel, wheel bolts, and wheel nuts as applicable. Many factors must be considered in design and validation of wheel attachments for each specific vehicle. The individual components should be evaluated per the SAE standards referenced.

The purpose of this test is to evaluate the axial strength of the nut seat of wheels intended for use on passenger cars, light trucks, and multipurpose vehicles. In addition, a minimum contact area is recommended to ensure enough strength for the rotational force in tightening a nut against the nut seat. While this test ensures the minimum strength of the nut seat, the wheel must also have a degree of flexibility. This flexibility, as well as bolt tension, are important to maintain wheel retention.