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This paper describes the development of a heavy-duty light-weight truck drive axle air suspension for use on single and tandem axles. A review and evaluation of various air suspensions is made to establish design parameters and their application to the new Series 400 unit. Mathematical analysis and detail photographs are included.

A technique is described for diagnosing the vibration source in a vehicle as it is driven on the road. The basic problem is to determine whether the vibration is related to excessive engine or transmission vibration, driveshaft imbalance, driveline misalignment, U-joints, differential, or whell assembly imbalance; and, in the latter case, to isolate which faulty wheel. The technique developed is to integrate samples of the vibration signal taken synchronously with the various rotating parts. The feasibility of the technique was demonstrated on two heavy trucks and several passenger vehicles.

In common with other owners and operators of large fleets of vehicles, the U.S. Army is faced with a major maintenance task. A significant part of this task is the correct and timely diagnosis of the vehicle faults which cause down time and those which can propagate into secondary, and usually more serious, damage. The Army, of course, has two operational situations which differ in type and degree from those of commercial fleets. First, the duty cycle for Army vehicles is less predictable and instant availability is essential. The second is that Army vehicles are armored, shielded and waterproofed (fordable) to an extent that test point access is severely limited in comparison to commercial vehicles. To grapple with this situation, the U.S.

The Maintenance Indicator System (MIS) is a completely automatic system that monitors the condition and performance of critical subsystems and accessories of a vehicle and its engine. Although designed specifically for the military 2-1/2 ton and 5 ton trucks, the indicator system can be adapted to most military and commercial vehicles with minor modifications to suit the particular requirements. MIS consists of a dashboard-mounted display panel located in full view of the operator and connected through a wiring harness to sensors permanently mounted on or within various systems and accessories of the engine and vehicle. The sensors monitor critical parameters and alert the driver or mechanic by a light activated on the panel when service is required or a malfunction has occurred.

Enactment and enforcement of stringent smoke emission regulations has created need for a method to determine if the exhaust opacity of in-service vehicles exceeds legal limits as they are driven on the road. This can be accomplished by running a 3 min chassis dynamometer test cycle, which is based upon the Environmental Protection Agency diesel engine certification procedure. Simultaneous recordings of speed and exhaust opacity permit modal analysis for identification of specific malfunctioning components and consequent improved cost effectiveness of maintenance expenditures.

This paper defines the need for more complete diagnostic systems as options for heavy commercial vehicles. Areas and indicators are defined for current and future operator requirements. Return on the operators investment is demonstrated on the basis of vehicle utilization. Current prototypes and pilot evaluations are discussed.

A digital signal analysis system to aid in compiling vibration test data is described. The objectives of the system are explained, mathematical properties are derived, and system operation is discussed with respect to hardware, characteristics, and sample output. This method for digital filtering of time series data has proved to be fast, effective, and an easily implemented method of analyzing structural properties. In addition to providing the design engineer with all of the traditional forms of output offered by analog systems, the computer-based nature of the digital filter system facilitates the use of large-scale dynamic simulations requiring mode identification and other analytical software.

The objective of this paper was to establish the degree of correlation between the results obtained from a 3/8 scale plastic model, an actual frame, and a mathematical computer model. Results showed that a satisfactory dynamic simulation can be obtained from a scaled plastic model of the structure and that a mathematical model composed of beam elements is accurate at the lower frequencies but begins to differ with the actual frame at higher frequencies.

This paper presents the performance of epichlorohydrin homopolymer (CO), the epichlorohydrin/ethylene oxide copolymer (ECO), and a polypropylene oxide elastomer (PPO) when subjected to various environments at elevated temperatures. Comparisons with other oil-resistant specialty elastomers before and after aging in air and oil are discussed. Low-temperature flexibility, elongation, and other properties are included, as well as permeability evaluations. The data demonstrate the improved performance of polyether elastomers for a service temperature range of -40° to 300°F, especially for under-the-hood applications.

Using several variations of a basic finite element model, the dynamic displacement response and mode shapes of an automotive frame have been predicted. Small improvements in accuracy were noted when higher-order mass representation and allowance for shear deformation were included in the analysis. Modeling accuracy was significantly increased, however, by including certain effects which are normally ignored. These include an allowance for the less-than-perfect rigidity of siderail-to-crossmember joints; for the torsional behavior of short, open cross-section beams; and for the reduction of flexural inertia in welded, double-channel cross-sections. With the introduction of these factors, the predicted natural frequencies for the first eight flexural modes can be correlated with test results to within 4%. For this level of agreement, the finite element model appears to be sufficiently accurate to be used in design evaluation of frames, prior to prototype construction.

This paper reviews development work in optimizing the heat resistance of polyacrylate elastomers. An expansion of the range up to 400°F, from the present 325-350°F, is currently being explored with the evaluation of fillers, curing systems, and other compounding ingredients. Data are presented comparing soap-sulfur and ammonium-type curing systems, and also for different combinations of carbon black and reinforcing mineral fillers using a soap-sulfur curing system.

Design activity on the University of Detroit's (U of D) entry in the 1972 Urban Vehicle Design Competition began in September 1971 with 60 senior engineering students in an interdisciplinary design course. Preliminary design considerations for powerplant, power train, emission controls, safety features, and styling were completed by December 1971. Development of hardware started in January 1972 with a 15-man team. Final configuration resulted in the modification of a 1970 Ford Maverick, shortened approximately 5 ft to a final length of 121 in and widened 1 ft to a width of 80 in. Features include 5 mph bumpers, automatic transmission, stratified charge engine, offset driveline, high level exterior lighting, side door beams, three occupant capacity, roll bar, front disc brakes, and electrically driven fan for cooling system.

Chemical vapor deposition (CVD), the deposition of solids by chemical reaction of gaseous feed materials, is older and more complex than vacuum coating. For a long time it remained a laboratory curiosity; however, in recent years, it has become firmly established in many areas of technology, and new applications are being found. CVD is a versatile process, yielding deposits of many metals, alloys, semimetals, oxides, carbides, nitrides, and borides, and it has several advantages, the greatest of which is superior throwing power. However, to use it effectively requires an understanding of such factors as the chemistry of the available coating reactions, the chemical and thermal stability of the substrate being coated, and the effects on mass transport of the various vapor flow patterns encountered in coating objects of simple to complex shape. The range of applicability of CVD is discussed with examples, and guidelines are given for successful coating.

An experimental urban car was designed and built by Western Washington State College as an entry in the international Urban Vehicle Design Competition. The car was designed with a novel form of mid-engine rear drive chassis. A novel (pyramid link) rear suspension solves many problems. Extreme Ackerman steering allows a 9 ft turning radius. New systems were developed for adjustable pedals, steering, and seat squab height. The chassis quick-disconnects into three major sections to facilitate servicing. A bias beam brake linkage allows easy adjustment of front-rear brake bias. The low emission engine runs on propane and is equipped with a thermal reactor and an EGR system. The body chassis center unit is made from epoxy fiberglass surface aluminum honeycomb. Passive restraint seat belts are attached to semigull wing doors. Five mph bumpers are fitted to each end. The front uses extrusion bolts and the spare tire; the rear uses beverage cans in compression.

A team of industrial design students designed and built a prototype urban taxi that overcomes several disadvantages of contemporary production taxis including: inadequate interior driver and passenger space, bulky exterior dimensions, and inconvenience to physically handicapped passengers. The vehicle employs a diesel powerplant in the interest of operating economy, reliability, and decreased air pollution. The body, consisting of flat panels fastened to a simple steel rollcage, is suited to low volume production and simple maintenance. Aesthetically, the vehicle was designed to harmonize visually with the urban environment.

Recent advances in electron beam evaporation, using automated vacuum coating systems, are dramatically increasing the use of physical vapor deposition for both decorative and functional coating applications. Some examples of these applications are: 1. The use of new metals, including alloys, to provide improved corrosion and/or abrasion-resistant coatings for plastic substrates. 2. The use of new metals and oxides to provide new decorative effect. 3. The use of evaporated thick coatings of clear glass-like materials to protect thin metal coatings. 4. The use of evaporated thick coatings of clear glass-like materials to provide a hard surface on clear plastics used for glazing and opthalmic applications. 5. The use of evaporated copper as a strike-coating for subsequent chromium electroplating. 6. The use of multicomponent alloys to coat gas turbine engine vanes and blades to provide improved sulfidation and oxidation protection. 7.

The purpose of this paper is to describe the design and simulation of the urban vehicle power train system of the University of Wisconsin at Madison. The objective of the power train is high fuel efficiency as well as low emissions. Fuel efficiency is achieved by an on-off operation of the internal combustion engine with the “on” operation at only the minimum brake specific fuel consumption area. Emission control is partially achieved by utilizing an electric drive system for transient response. Furthermore, low emissions and fuel efficiency are bettered by techniques such as special starting without choke, no deceleration, and no idle requirements on the internal combustion engine.

The sputter coating process is reviewed, with particular emphasis on applications in the mechanical sciences. In addition to principles and methods of d-c and RF sputtering, the techniques of reactive, bias, and getter sputtering are described. Special attention is given to the plasma discharge as it relates to the achievement of high deposition rates and large substrate areas. The current state of development of sputtering equipment is examined from the point of view of its influence on coating properties and applications to production. Future prospects are discussed. It is concluded that significant increases in both deposition rate and area of coverage can be expected for d-c sputtering systems operating with cylindrically symmetric geometries. Less spectacular improvements are projected for RF sputtering.

The design and construction of a Wankel-powered, rear-engine, rear-drive urban vehicle was undertaken by students in the engineering and industrial design curriculums at The University of Michigan. The goal of this group was to submit a competitive entry to the Urban Vehicle Design Competition conducted in August 1972, and hopefully to provide some fresh solutions to the problems of urban transportation. Constraints set by the UVDC Committee as well as proposed federal emission and safety standards were considered as governing parameters in the design process. This report describes some of the many features of the University of Michigan entry and includes a discussion of the primary merits of the project.

In the past 20 years in the United States, the demand for energy has doubled, and it is expected to increase by 3.6% annually until the end of the twentieth century. This paper discusses the implications of the increased demand, and the resources needed to meet it. Nuclear power is seen as a partial answer, as is low-sulfur coal. Some untapped oil reserves are available in the United States, but oil will undoubtedly have to be imported to meet the demand. A concerted effort to conserve energy is needed to help hold imports to acceptable levels.