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A Bus for Denver?셲 Mall | A unique shuttle bus is being constructed by Minicars, Inc., and Walter Vetter Karosserie-werk for Denver?셲 Transitway/Mall. The bus is designed for frequent stop, low speed service in a downtown pedestrian environment. It features a very low floor and multiple wide doors for rapid passenger boarding and deboarding. Two versions will be supplied for comparative evalation, a low noise diesel configuration and a battery-electric configuration. Either version can subsequently be converted to the alternative propulsion system. |
State-of-the-Art-Ergonomics and Motor Vehicle Safety | The use of ergonomics in the design of vehicular equipment is presented. It is proposed that the wider use of the principles and methods of this discipline might aid in the more effective integration of the driver and his equipment. It has been shown that the effectiveness of any man-machine system depends upon the integration of the biological characteristics of the operator with the mechanical design of the equipment and working areas. The initial phase of a program in ergonomics should always consist of an advance analysis of the equipment, including a survey of the nature of the task, the work surroundings, the location of controls and instruments, and the way the operator performs his duties. In highway safety the application of human engineering principles has been shown to be of great importance in the design of windshields, rear view mirrors, and vehicle lighting, and other visual aids to the drivers. The field of crash injury research is proving to be especially important in understanding the parts of the vehicle most likely to give rise to injury. Current research is tending to give more precise measurements not only in regard to the forces involved, but also to the thresholds and patterns of injury. The various research programs in the field of ergonomics as related to highway safety in various parts of the world have greatly increased in recent years. |
Reducing Construction Equipment Cooling System Noise to Meet the French Noise Requirement | A major noise source on construction equipment is the cooling system when tested according to the French Noise Test Procedure. This paper describes the procedure and methods used to reduce economically the Case 580B CK loader-backhoe cooling system noise to 75 dB(A), well below the French limit of 80 dB(A) for the whole vehicle, and remain within the desired physical and performance constraints. This was accomplished primarily by reducing fan speed and using a larger capacity radiator to maintain adequate cooling. |
Experimental Studies of the Space Shuttle Payload Acoustic Environment | Two series of experiments were conducted to reduce the uncertainties concerning the Space Shuttle payload bay acoustic environment. Tests using a one-fifth scale model showed large changes in level below 125 Hz with the introduction of typical payloads. The changes were associated with particular acoustic modal behavior and were sensitive to the type of acoustic excitation. Another series of experiments evaluated the noise reduction of the first orbiter vehicle (OV-101). The results showed consistently greater noise reduction for grazing excitation than for diffuse excitation. The results were extrapolated to OV-102 using mass law relations and acceleration measurements. |
Light Vehicle Frontal Impact Protection | This paper addresses the protection of occupants in light vehicles. It presents data and techniques for identifying and measuring potential crashworthiness improvements that would mitigate injuries to occupants striking frontal interior components such as the steering wheel, instrument panel and windshield. Both restrained and unrestrained occupants can be injured by frontal interior components in crashes. The focus of this paper is on the unrestrained occupant. However, performance criteria and associated countermeasures will have to be developed considering the differences in the mechanisms of injury to both the restrained and unrestrained occupants. Work on the restrained occupant and the similarities and differences between both conditions remains to be considered. The paper presents information on the magnitude and types of injuries received from frontal interior components and on how the performance of these components and the vehicle structure affect the resultant injuries. |
GMC Fiberglass Truck Door | A new fiberglass door was designed to replace steel doors on GMC heavy duty trucks as a quality improvement while reducing cost and weight. A feasibility study led to the selection of SMC for the door material. The new design incorporated unique design features and innovative materials applications. Finite element analysis was used to determine optimum material distribution for reducing stress and weight and for increasing stiffness. A test program was conducted which verified the design criteria and objectives were met. |
A Subjective Assessment of Truck Ride Quality | A subjective assessment of ride quality was undertaken in order to estimate the relationships among 22 factors that affect concepts of ride quality and to assess the interaction of these factors with 7 ride quality issues. Nine line-haul drivers drove and rated each of 16 tractor-trailer vehicles. The factors, driver vibration, ease of steering, and interior cab noise determined overall impressions of ride quality. Of the issues, front axle load, tractor configuration, tractor rear suspension, trailer suspension, trailer load, wheel base length, and newer and older cab designs, the latter evoked the clearest differentiation of ride quality between paired vehicles. |
Reduction of Traffic Noise Impacts Via Path Controls | Path control measures to reduce traffic noise impacts include roadway alignment, site planning, noise barriers, and building insulation. Roadway alignment and site planning are most effective when included during the project planning stages. For existing noise problems, roadside noise barriers are effective, providing reductions of up to 15 dB(A). Some sites require building insulation to reduce traffic noise impacts. Three levels of modifications are considered: (1) sealing leaks, (2) modification of small structure elements, and (3) wall panel modifications. |
Side Impact Modelling Using Lumped Mass and CAL-3D CVS Simulations | Experimental research to improve protection levels offered to automobile occupants in lateral collisions has focused on the study of responses of the 50th percentile male as a result of the availability of the Side Impact Dummy of that size. The question of the suitability of protective measures developed for the 50th percentile male for the other occupant sizes is of concern. Hence, a major objective of this study was to analytically evaluate injury potential of a broad range of occupant sizes in lateral collisions in combination with various types of padding. Two computer models were used in the study. The first was a one-dimensional lumped mass model. The CAL-3D crash victim simulation was also configured to represent an occupant in a lateral collision with intruding door motion. Results of the study indicate that padding on the interior of the door surface is beneficial to all occupant sizes. |
Interior Noise Reduction in a Recreational Van | A study was made to determine the effect of combinations of acoustic treatments on the interior noise levels in a 3/4 ton van. The effect of barriers, absorbers and vibration dampers in various combinations on the dBA levels are given for both idle and highway operating conditions. A noise reduction of up to 10 dBA was obtained for certain barrier and absorber combinations. |
APPLICATION OF THE FINITE ELEMENT METHOD TO THE DOOR INTRUSION AND ROOF CRUSH ANALYSIS OF A PASSENGER CAR | In order to satisfy the various international safety standards which currently exist, it is necessary that nearly all new vehicles be subject to a number of destructive tests before being made available to the public on the open market. Development programmes involving a series of such tests are very expensive and there is a growing need that reliable and economical design/analysis methods be made available. This paper attempts to present such a method. Using a relatively simple finite element computer program which has been adapted to the particular needs of the motor industry, the analysis of a new prestige limousine is described. A background to the analytical method is presented, but the emphasis of the paper is on the engineering aspects of using the method. Reference is made to practical design considerations in several instances. The results of calculations predicting the performance of the structure when subject to FMVSS 214 and 216 are presented. |
External Surface Noise Radiation Characteristics of Truck Diesel Engines - Their Far-Field Signatures and Factors Controlling Abatement | The engine is an important source of diesel powered vehicle noise, and becomes dominant after proper treatment of exhaust and cooling system noise at vehicle speeds below fifty miles per hour. This paper presents the results of a comprehensive study dealing with surface noise radiation characteristics and the ranking of sources on three truck diesel engines. A special acoustic facility constructed to emphasize the acquisition of diesel engine noise data is describad. Information is presented on measurement methodology and its viability for quantification of engine noise, directivity, and radiation patterns from engine surfaces. Acoustic measurements, conducted over a range of engine loads and speeds, include spectral analysis of the sound pressure field derived from a thirtytwo microphone spherical array. Various noise identification techniques are explored under comparative testing to ascertain potential candidates for quantification and ranking of engine external surface radiation. For the engines studied, the sound power output varies, depending on design; the loudest being the naturally aspirated; and the quietest being of prechamber design. This range varies between 8 and 10 dB (A) at maximum throttle and is speed dependent. Turbocharged engines exhibit a marked change in sound power output under increased load conditions. This is most pronounced at lower engine speeds. The sound pressure field of two in-line turbocharged four-stroke diesel engines contained a high degree of asymmetry whereas the sound pressure field of a two stroke vee configuration engine appeared representative of a finite monopole acoustic radiating source. Major external engine surface acoustic radiators, common to all engines tested, included engine front, block sides, and valve covers. Other major external sources were after-coolers and exhaust manifolds for specific engine designs. Oil pan noise, although a lesser contributor to overall engine noise, depends on factors which include the design, material and construction. Finally, comparisons are made of noise data acquired for the acoustic facility and data acquired for the same engine installed in a typical highway truck chassis located out of doors. |
Noise Reduction of a U.S. Army 5-Ton Truck | Research is demonstrating that it is possible to significantly reduce the in-cab noise levels of the Army's current truck fleet, with accompanying exterior noise reduction. Results are applicable to future Army trucks as well and are reported on a program utilizing a 5-Ton Army Truck. This type of truck was found generally to exceed the applicable limits established in the new MIL-STD 1474, ?쏯oise Limits for Army Material.??The program identified major noise sources and important paths for sound to enter the cab and resulted in the selection of optimum sound absorption, sound barrier and vibration damping materials. The effect of a prototype exhaust system and its placement relative to the cab and the importance and optional means of controlling cooling fan and engine noise were also investigated. |
The Evolution of Sound Testing at Kohler Co. | The purpose of this paper is to discuss the development of Kohler Company's Small-Engine Noise Test Program. Particular emphasis will be placed on noise instrumentation and analysis techniques. The paper will not dwell on the specifics of each noise study technique, but will be an overview, describing the evolution of Kohler's Noise Test Program in general. |
Development of Lightweight Door Intrusion Beams Utilizing an Ultra High Strength Steel | Door intrusion beams have been fabricated from an ultra high strength steel resulting in an efficient side impact protection system. Despite the ultra high strength (yield strength??50 ksi) the steel may be roll formed into beams from thin gauge material (0.035 in) resulting in significant vehicle weight savings while still meeting all federal specifications. This paper covers the development of this door intrusion beam system and includes detailed descriptions of beam design, beam testing and steel properties. |
Hailstone Response of Body Panels - Real and Simulated | The dent resistance of aluminum and steel autobody panels has been studied under controlled laboratory conditions and by field observations and measurements of actual hailstone damage. Analysis of the results shows that very nearly the same response occurred in the lighter weight aluminum components as occurred in the steel panels. The autobody components were all 1977 model year production panels. Laboratory testing included four steel and four aluminum hoods, both painted and unpainted. The hailstone damaged components included a steel hood, aluminum doors and an aluminum fender. The aluminum and steel panels were damaged in the same hailstorm during May 1977. The analysis of denting resistance presented in this paper is based on insight and experience gained from a four-year cooperative program of Reynolds Research and several automobile companies. The results given here supplement previously published laboratory data and confirm the conclusion that lighter weight aluminum autobody panels can be designed to give at least comparable, if not better, dent resistance than conventionally used steel panels, and at a weight savings of 50 percent. |
New Designs Through Vibration Welding | A new plastics assembly technique has been developed which offers new opportunities in product design and assembly as well as new solutions to existing problems. This method, based on friction welding, overcomes many limitations of conventional welding processes such as part size, shape, material and speed of operation. It produced strong, pressure tight joints. |
Evaluation of Cooling System Design for a Portable Air Compressor Designed to Meet EPA Noise Requirements | A cooling system design for a gasoline engine powered portable air compressor designed to meet EPA noise standards is evaluated. This paper covers the development that took place in order to devise an adequate cooling system for a silenced compressor with noise reduced by shrouding of the machine with a sound attenuating housing. The successful cooling system consisted of resolving maximum engine coolant temperature and maximum compressor discharge temperature while maintaining a compressor noise level of 76 dBA at 7 m. The cooling system design procedure involved is outlined. Noise evaluation at Sullair Corporation, and cooling system testing at McCord Corporation are reported. |
Highlights of UMTA's Rail Program | This paper highlights the role rail research programs of the Urban Mass Transportation Administration (UMTA). Included are descriptions of several recently developed commuter transit cars-the state-of-the-Art Car, The Advanced Concept Train and dual-powered, gas turbine/electric cars. Also discussed are efforts by UMTA in developing test facilities for urban rail vehieles and in furthering research in tunneling technology and noise abatement. |
Designing Body Panels for Corrosion Prevention | To aid in avoiding the corrosive elements of the environment, the designer of sheet metal body panels should consider principles which provide optimal drainage and access for the application of protective coatings. Major vehicle body components are considered individually or in closely related pairs such as door inner and outer panels. The general guidelines for preferred construction of drain holes, shingling, shielding and access for material application are outlined for each major component. |
A Method for Assessing Turbine Engine Run-Up Noise Impact on Airport Neighbors | A methodology for assessing ground run-up noise exposure/impact resulting from turbine engine performance testing on outdoor facilities was developed. The overall methodology consists of three calculation procedures using dBA levels (measured or estimated) to predict the Day-Night Level (LDN) at any location across existing terrain. The methodology provides the analysis capability required to 1) study noise suppressor requirements in order to minimize costs, 2) locate run-up and test-cell pads, and 3) study the impact of run-up operations changes. It also provides a potential capability for assessing noise exposure from 1) takeoff power check run-ups, or 2) other (non-turbine) static noise sources. |
Experimental Approach to Reduction Technique for Engine Noise in Passenger Compartment | This paper deals with high frequency noise in the passenger compartment which are caused by transmitted engine noise. For the purpose of noise reduction, several evaluation methods are developed. For the evaluation of a body transmission loss, a combination of a reverberant room and an anechoic room is used. The noise absorption of the compartment is evaluated under the concept of the saturated sound pressure level. And sufficient standard samples are measured to support the noise reduction development. |
Noise Control on a Heavy-Duty Mobile Crane | The intent of this paper is to illustrate how simple testing techniques and application of elementary noise concepts helped attenuate the noise in the operator cabs of a heavy-duty mobile crane to within the 8 hour/90 dBA limit established by the Occupational Health and Safety Act of 1970. |
A Modern Technology, Open-Ocean Seaplane Design | Modern technology has been applied to derivation of a viable open-ocean seaplane design capable of operation from, and sea sitting in, sea state 5. Beginning with a delineation of traditional seaplane limitations and philosophically unencumbered by orthodoxy, the design features a blended catamaran-fuselage hull, hydrofoil, high wing, twin boom, and Vee tail with top-mounted engines. Weighing 1.25 million pounds including weapons and avionics suite, the design has been applied to a Sea Control mission. Consideration has been given to concepts for inhibition of motion sickness. |
Flight Displays for the Next Generation Aircraft | The influence of the increasing complexity of the commercial transport operating environment is cited as the reason for applying advanced display technology to new aircraft design. Principal factors are the fuel crisis, sensitivity of the environmental noise, and the need for increased traffic capacity. Industry-wide development programs for fully configured flight decks, as well as specific subsystems, are reviewed. |
Reduction of JT8D Powered Aircraft Noise By Engine Refanning | The purpose of the Refan Program is to establish the technical feasibility of substantially reducing the noise levels of existing JT8D powered aircraft. This would be accomplished by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdB for the B727-200 aircraft and from 10 to 12 EPNdB for the DC-9-32 aircraft at the FAR Part 36 measuring stations. These noise levels are lower than both the FAR Part 36 noise standards and the noise levels of the wide-body DC-10-10. Corresponding reductions in the 90 EPNdB footprint area are estimated to vary from about 70% for the DC-9 to about 80% for the B727. The refanned aircraft should perform typical range/payload missions with a negligible effect on block fuel. Production retrofit kits could be available in 1976 for the DC-9 at a unit cost of about $1.0 million and in 1977 for the B727 at a unit cost of $1.7 million. |
A Noise Control Study of Certain Diesel-Powered Strip Mine Vehicles | This paper describes the work performed in three distinct noise studies on typical diesel-powered strip mining equipment and discusses their results. Mufflers lowered diesel exhaust noise exposure for adjacent workers and the community at large, but had little effect on the noise level at the operator's position. Properly designed and installed noise control kits can be an effective method of reducing the operator's exposure to an acceptable level, and can simultaneously dampen vibration inside the cab. |
An Investigation of the Noise and Overpressure Generated by the Safety Air Cushion | The results of an experimental study of air cushion noise and overpressure are presented, and methods to reduce these effects are investigated. Free-field studies of inflator noise are made in an open anechoic room, and various silencing devices are tested. Studies are also made of the combined inflator noise and overpressure in a closed passenger compartment. Tests are made for different window openings in the compartment. Results are presented for a new experimental air cushion that draws in air from the passenger compartment as it inflates. Some of the implications of the data with regard to risk criteria for damage to human hearing are discussed. |
Experimental and Theoretical Study of the Rolling Noise in a Passenger Car | This paper presents an analysis of low frequency noise production by experimental measurements and mathematical model calculations. It shows vibration coupling between train, body and cavity modes and it points out different possibilities to reduce noise in the passenger compartment. |
A Method of Sound-Field Simulation for Automobile Passenger Compartments | By estimating the sound field characteristics of an automotive cabin at a period prior to the actual manufacture of a car using available information on interior size, shape and acoustic materials, it is possible to realize a car audio system of high quality through appropriate placement of loundspeakers and determination of best electrical compensation networks, among others. We have established a computer-aided method based on the sound ray-tracing method and digital signal processing techniques usually applied to the analysis of large concert hall acoustics, which simulates the transmission characteristics between a loundspeaker and a listening position. |
Advances in Vibration Welding Technology | The primary objective of this paper will be to focus attention on recent major advances in vibration welding technology which directly apply to the automotive industry. Breakthroughs in large part welding capabilities, combined with product improvements, now extend the range of current joining possibilities, opening the way for new and innovative automotive product design. Welding reinforcements up to 50??(127cm) long, to an all plastic bumper, has become a reality with the development of a large part vibration welder (LPVW). Currently in production, this new technology and equipment can also be applied to other large part applications, such as welding structural or support members onto large exterior components, i.e.: hood and trunk lids, quarter panels, valence panels and spoilers. Improvements in standard sized welders such as advanced process controls and built-in flexibility will offer significant gains in weld quality, automation, adaptation and overall productivity. A discussion of basic theory and principles of operation will be essential for background Information, along with equipment descriptions ranging from standard welders to special large part vibration welders. Details such as part size capabilities, operating parameters, and equipment selection relative to specific types of applications will be described thoroughly. Examples of successful assembly applications in areas such as fuel management, exterior lighting, ducts, and under-the-hood components will be used for capability familiarization. |
Dolby Noise Reduction in Automotive Applications | In the past decade, the high frequency response of automotive tape playback equipment has been extended, the efficiency of loudspeakers has increased and the cost of high power amplifiers has been reduced. Consequently, tape noise can be a significant problem when listening in the car. This paper discusses the design philosophy of the Dolby B-type and C-type noise reduction systems that are now widely used throughout the in-car entertainment industry to overcome the tape noise problem. Information relating to basic tape parameters, to other approaches to noise reduction and to noise reduction system defects is also included. |
Recent Development of Plastic Material for Automotive Interior Application | In addition to weight reduction and cost reduction, maintenance of the initial quality has become an important subject including color matching after long years of use since automobiles are used for longer years these days. This paper decsribes an outline of our manufacturing process of instrument panel pads, characteristics of the new surface material which we developed for above requirements, quality comparison of the surface material with those by other methods, possibility of applying this new method to other interior parts, for example, door trim, and so on. |
Noise and Vibration Reduction Measures Applied to Diesel Engine Cars | Some instances of the corrective activities concerning the noise and vibration problems such as idle noise, idle shake, driveline rattle, intake noise and booming noise experienced in the development stage of new diesel engine passenger cars are introduced here. |
Application of Acoustic Modeling Methods for Vehicle Boom Analysis | This paper describes a system modeling technique for predicting passenger compartment ?쐀oom??for a specific car design prior to the building of a prototype vehicle. Since ?쐀oom????defined here as auditory response in the 20 Hz to 80 Hz frequency range ??is dependent on body panel vibrations as well as air acoustic properties, three-dimensional finite element models of both body and air are constructed. These models are incorporated in existing vehicle models which include powertrain and chassis representations of the type previously used for performing shake and harshness analyses. To avoid non-symmetric mass and stiffness matrices, a modal method using auxilliary variables is utilized to couple the acoustic and body models. Included in the paper are discussions of modeling issues unique to structural acoustic simulation as well as several examples of studies in which sound pressure level response to realistic inputs is predicted and reduced by simulated design modifications. Test results are presented for comparison. Finally, graphical presentation of panel acoustic contributions is shown to be a useful tool in selecting possible body structure design changes for ?쐀oom??improvement. |
A Review of Glazing Road Use Conditions and Laboratory Simulations | This paper addresses glazing road use conditions and presents the results of a research program which investigated laboratory simulations of road use A review of current testing requirements for glazing used in locations through which driver vision is required is presented to introduce the development of improved glazing performance factors. The focus of this paper is the perceived need to insure the continuing use of realistic safety performance tests as new glazing technology emerges. This paper presents results of test simulations on glass, plastic, and glass-plastic materials using elements of a road use exposure model. Both sequential and non-sequential types of testing were evaluated. |
Application of Finite Element Methods to Vehicle Interior Acoustic Design | This paper describes the capabilities of the finite element method for vehicle interior acoustic analysis. Structural and acoustic finite element models of a van-type vehicle are employed to illustrate the implementation of the method in the design stage. Included as representative examples are studies of the acoustic resonances and forced acoustic response of the compartment cavity, which provide preliminary guidelines for initial compartment acoustic design. At a later stage, when the vehicle structural model has been developed, the finite element models of the structure and the passenger compartment cavity can be coupled for a total vehicle system evaluation. The paper illustrates the accuracy of the coupled model by comparison with the measured response in the van. Finally, the systematic application of this finite element methodology in a computer-aided procedure for the acoustic design of the passenger compartment is discussed. |
Analysis Systems for Acoustic Intensity Noise Measurements | The sound intensity calculation techniques have been implemented on a variety of instruments, but an integrated system application of the intensity technique offers more functional freedom and expandable processing options. This paper deals with a brief background of the system implementation of sound intensity methodology and its general application. |
Development of Sound Localization Control System for Car Stereo | In a two-loudspeaker stereophonic reproduction system of a passenger car, the geometrical configuration of the right and left loudspeakers has the disadvantage of being asymmetrical to the listener. For this system, we have made both theoretical and experimental verifications of the effects of strongly reflected sounds on the sound pressure level difference and phase difference between two ears which determine the location of sound image in a small compartment of a passenger car. On the basis of these verifications, we have developed a new sound localization control system. With this system, acoustical effects such as sound expansion and ambience have been greatly improved in a passenger car. In this system, input signals to the loudspeakers are controlled so that the sound image produced by the loudspeaker nearer to the listeners may acoustically move so as to position itself symmetrically with the other loudspeaker with regard to the listeners. The corner-mounted loudspeaker and the sound localization control circuit constitute the distinctive features of this system. The corner-mounted loudspeaker suppresses strongly reflected sounds, which are characteristic of the sound fields in a passenger car, and improves the definiteness of acoustical sound localization. The corner-mounted loudspeakers are installed toward the corners of the intersections of the instrument-panel near the right and left doors so that the directivity axis of loudspeakers makes an equal angle of 45 degrees with the two vertical planes passing through the instrument-panel and each door. The sound localization control circuit consists of an inverter, a pre-amplifier and a delay circuit unit. This control circuit is connected to the power amplifier output stage of a conventional audio components. With this circuitry, acoustical effects such as sound expansion and ambience are greatly improved. |
Aerodynamic Characteristics of the Fiat UNO Car | The purpose of this article is to describe the work conduced in aerodynamic field throughout the 4-year development and engineering time span required by the project of the UNO car. A description is given of all the parametric studies carried out. Through these studies two types of cars at present in production were defined and the characteristics of a possible future sports version laid down. A movable device, to be fitted in the back window, was also set up and patented. When actuated it reduces soiling of back window. A description is also provided of the measurements made in the car flow field and some considerations are outlined about the method applied. This method is still in development phase but it already permits some considerations and in-depth investigations to be made on the vehicle wake. |
The National Highway Traffic Safety Administration's Evaluations of Federal Motor Vehicle Safety Standards | A history of the evaluation of existing motor vehicle safety devices by the National Highway Traffic Safety Administration and other researchers. The discussion emphasizes observations of researchers toward the safety standards and the extent to which these have influenced or were influenced by evaluations. Issues concerning energy absorbing steering columns, head restraints, side door beams and windshield glazing and bonding are covered in detail. This paper presents the views of the author and not necessarily those of the National Highway Traffic Safety Administration (NHTSA). |
System Electromagnetic Compatibility Through Component Testing - An Overview | By nature, automotive electronic systems are susceptible to Electromagnetic Interference (EMI). Devices capable of suppressing EMI have become an integral part of the automotive electronic system design. Methods of testing these devices individually and as part of the total electronic system have been developed and used as a design tool by the engineer. These methods range from individual component tests to total electronic system analysis and cover such areas as radiated noise susceptibility and the effects of electrical transients on the electronic system. The ability to test components in the laboratory allows the engineer to assemble reliable subsystems from which a total electronic system may be designed. Components and subsystems may be tested using a TEM cell, anechoic chamber and/or direct injection of noise signals. Computer control of the test provides repeatable results and better turn-around time than can be obtained by manual testing. This paper will present different methods of performing Electromagnetic Compatibility testing on components and electrical subsystems. Procedures for characterizing susceptibility to EMI will be reviewed and its applicability to the design process will be discussed. Case histories will be included to illustrate the advantages of component and subsystem testing to total vehicle analysis. |
Application of Acoustic Intensity Measurement to High Frequency Interior Noise | This paper describes the application of an acoustic intensity measurement method to high-frequency interior noise. Technical problems in applying an averaging technique via surface scanning to high-frequency interior noise were conquered, and detailed quantitative contribution analysis of interior surfaces was made possible. Based on the analysis of a small passenger car, the effectiveness of additional noise control treatment can be roughly estimated, and an acoustic confort of the car was improved by a minimum additional treatment required. |
Aeroacoustic Flight Test of Four Single Engine Propellers | A flight test program has been conat the Aeronautical and Astronautical Research Laboratory (AARL) of The Ohio State University to measure performance and acoustic characteristics of four propellers designed for use on single-engine general-aviation airplanes. Three of the propellers were designed to reduce acoustic noise, while the fourth was a standard production propeller used for comparison. The tests show that notacible reduction in near-field noise was achieved at a constant propeller rpm, and that comparable aircraft performance may still be maintained. |
Application Of The Finite Element Method To The Design Of The Front Door Of A Light Commercial Vehicle | The paper describes the development and application of a relatively fine mesh model, analysed using MSC NASTRAN, to predict absolute values of deflections which correlated closely to the mean measured deflections of the actual door. The model has proved valuable in identifying and correcting at the pre-production stage the problem of the front door fit conditions. The paper then discusses the application of the model for structural analysis using strain energy techniques. The resulting design gives 21% reduction in deflection and stress at critical points with only 3% increase in mass. This contributed to significant savings in proto-type testing and in addition, provided more efficient use of the material in the structure. |
Development of Multiplex Wiring System with Optical Data Link for Automobiles | This paper contains an explanation of a Multiplex Wiring System with Optical Data-Link for cars, which has been installed in the Toyota ?쏞entury??since 1982. In this system, a total of 64 signals related to door wiring are transmitted in a multiplex fashion, and the number of wires from the front right-hand door to the interior could be reduced from 46 wires, which were used with conventional wiring techniques, to 10 wires including 2 plastic optical fibers. This system also has various control functions which includes a door-lock control function. In order to give high reliability to this system, we have developed a new optical data-link as well as a new custom micro-computer. And in the automobile industry, such a large scale multiplex wiring system having high reliability is very innovative in our opinion and will surely have a large impact in the future. |
Maxi-Mini Car | This paper investigates an alternate design for a small car with maximum interior space. The most advantageous design was found to be a three seater vehicle with a possible fourth seat. The driver is positioned in the center of the vehicle. All seats are movable front and aft and sideways and the trunk is variable giving maximum space utilization and versatility. The car has unique folding doors which swing up far into the roof for easy accessability to all seats. Space for 3 or 4 people is provided in a vehicle of less overall dimensions than current designs. Through use of plastic materials weight is also lower guaranteeing excellent fuel economy. |
The Ejection Reduction Possibilities of Glass-Plastic Glazing | Ejection is a major problem in motor vehicle safety, with some 43,000 people per year being ejected from passenger cars, with some 6000 of these killed. About half of these people killed are ejected through glazing areas. The November, 1983, amendment of Federal Motor Vehicle Safety Standard 205 now allows the use of glass-plastic glazing anywhere in a motor vehicle. Our study has explored the ?쐓afety net??implications of glass-plastic glazing, produced by Saint-Gobain Vitrage, 3M, and DuPont for the anti-laceration implications but tested in our study for reducing ejections by controlled deformation after the glass layer or layers break. The inner plastic layers holds the broken pieces of a tempered side glazing together enough to reduce adult head partial ejection in side impacts, with the plastic layer trimmed to the glazing edges. By extending the plastic layer and securing it to the window channels, a 44 pound child moving at 20 mph toward the window may be stopped without ejection, with severe but possibly tolerable neck loads. Plastic layers which allow a greater deformation without failure appear desirable, to give glass-plastic glazing both a reduced laceration and a designed reduced ejection capability. This paper presents the views of the authors and not necessarily those of the National Highway Traffic Safety Administration (NHTSA). |
The Performance of Automobile Glazing in Urban Accidents | Laminated glass windshields have not yet been demonstrated to be safer than a less expensive, single sheet of tempered glass. Data from injury-producing urban traffic accidents in Australia, involving tempered glass windshields, reveal that while the windshield is a major cause of injuries, they were generally slight and rarely disfiguring. By modifying the method of mounting the tempered windshield and by controlling the particle count near the periphery of the windshield, the risk of laceration may be greatly reduced. |
Correlation Between Windshield Head Injuries and Laboratory Tests Part I: Feasibility of Relating Headform Impacts to Clinical Head Injuries | By duplication of glass fracture patterns, the feasibility of relating 22 lb headform impacts to head injuries sustained by occupants contacting the windshield in crashed vehicles has been established. For each suitable windshield sample selected from available 1966 to 1969 crashed automobiles, a vehicle analysis was performed. The unbroken sections of 33 selected windshields were subjected to dynamic loads using the 22 lb portable headform. This portable device mounted in a van is described. At impact, the deceleration and velocity were measured and lacerations rated on the basis of damage to simulated tissue and moist chamois. Achievement of duplication between headform and occupant head impacts permits a numerical assessment of windshield lacerative injuries and presents a tentative method for future programs involving correlation between laboratory and service performance. |
Side Impact Structures | New side safety structural changes have been developed for some 1969 model General Motors cars. The research covered two years, during which time crash situations were simulated and analyzed, field data were studied, and various approaches to side protection were investigated. A low-weight, high-strength steel beam was developed and positioned horizontally in the door. In addition, the supporting body structures were reinforced. The resultant structure reduced penetration into the passenger compartment during side collision tests by causing a deflecting action between the two cars, and by preventing ride-over of the striking vehicle into the struck car. Fisher Body has recently developed the basis for a static laboratory technique of testing that measures the strength of side impact structure in such a way as to allow tryouts of designs early in the program. Because of the number of GM cars designed each year, this will curtail the extensive time and cost factors previously involved in dynamic testing. |
Elastic Vibration Analysis of Passenger Car Bodies (Bending and Torsion) | This paper presents the outline of a theoretical analysis of bending and torsional vibration of passenger car bodies. Body structure is simulated by a framework with tension rigs and additional panel stiffnesses. The framework is a three-dimensional model for the bending and torsional vibration, or two-dimensional for the bending vibration, and is analyzed by the lumped mass system. All input data are calculated from drawings, and therefore characteristics of body structure are forecast and controlled in the design process. The analysis is also applicable to coupled vibration and forced vibration problems. |
Perforation Corrosion at Lapped and Cold Formed Portions in Cold Rolled and Galvanized Sheet Steels | In order to prevent corrosive parts such as hood, trunklid, door and side sill in an automotive body from corrosion, a new perforation corrosion test to simulate the corrosion at lapped and cold formed portions was conducted on cold rolled, galvanized, and zinc rich primer coated steels. Anti-perforation of galvanized steels with zinc of 95 or 128 g/m2 and galvannealed steel with zinc-iron of 59 g/m2 is remarkably improved compared to cold rolled DDQ mild steel so that they decrease the reduction in thickness to about 1/2 or 1/3. Especially galvannealed steel showed the highest protectivity. On the other hand, effect of steel itself on perforation is also observed among three uncoated steels. The EDDQ high strength steel has excellent resistance. The reason can be attributed to low manganese content and lack of surface segregation of manganese due to short time continuous annealing. |
Realization of Pedestrian Protection Measures on Cars | For the first time a working group of german universities developed an efficient, environmentally compatible and safe passenger car. The design of the UNI-CAR was specifically adjusted to the safety of persons outside the vehicle. Thus, for protecting pedestrians and drivers of two-wheeled vehicles, several of the bodywork components were primarily developed on the basis of polyurethane integral skin foam to cushion the impact of a person upon the car from outside. For instance, the car was given a reversibly deformable front end and a cushioned bonnet as well as cushioned window frames and roof edges, without impairing the design or aerodynamics of the vehicle. The report explanes the aspects of materials selection and vehicle design, the problems and experiences associated with the manufacture and application of these plastics components as well as test results. |
The All-Aluminum Auto Body - A Study Based on the Porsche 928 | An all-aluminum body in a unitized construction of a sportscar has been developed as a prototype. Design features, forming, welding, and surface treatment have been studied as well as the results of the test trials. A weight-saving of 47 % compared to an all-steel body was achieved with good characteristics of static and dynamic stiffness, operational reliability, passive safety properties, corrosion resistance, noise level, and repairability. |
Electric Vehicle Operational and Impact Safety Testing-Presentation of Test Results and Safety-Related Vehicle Problem Identification | The National Highway Traffic Safety Administration has completed safety-related testing of 13 electric vehicle models which are presently on the market. This report summarizes the results of the hydraulic brake, windshield defroster, and 30 mph frontal barrier impact tests which were conducted. Performance trends are discussed and safety-related problems and defects are identified. |
RIM Urethane/Vinyl Composites as interior Trim Parts | Approximately four years ago, new production process for automobile door liners was introduced in Europe. The process consisted of stretching a sheet of unsupported, expanded PVC over the mold cavity. The mold was closed and clamped and a polyurethane structural foam mixture was injected by the RIM method through the top half of the mold. The pressure and temperature of the expanding mixture forced the vinyl to conform to the contours of the cavity thus producing a finished door liner (polyurethane foam/vinyl composite). This process showed promise but had several drawbacks. Over the past two years, cycle times have been reduced to 2 minutes, intricate surface detail has been achieved and other formable surfaces have been substituted for the vinyls. These improvements have made it a candidate product for the U.S. auto industry. |
Quantitative Measurement and Predictive Techniques for Radio Frequency Interference | A technique for measuring and predicting radio frequency interference has been developed which can quantify an individual component?셲 performance, The assessment of a quantitative performance objective for each component provides a means to acheive a desired level of noise rejection for the system independant of environmental variances. |
Materials for Panel Damping in Motor Vehicles | This paper describes the application possibilities of materials for panel damping in modern motor vehicle construction. The basic parameters which govern damping are given; it is shown how they relate to motor vehicles. Two laboratory test methods are discussed for determining the damping performance of materials typically used in motor vehicles. Examples of the effectiveness of such treatment in the motor vehicle under normal operating conditions is presented and discussed. The influence of damping materials when combined with other typical noise control materials is shown in regards to performance and weight optimization. |
Torsional Vibration Measurement and Analysis: A New Technique | Torsional vibration measurements, while varying in complexity, are probably the least familiar type of vibration measurement. The high output demands imposed on today's engines require a complete understanding of torsional vibration. This understanding is necessary to insure proper function and durability of these engines and their components. The need for an accurate, reliable and durable measurement system that could be used for the evaluation of any engine application is essential. The measurement system has two basic components, an engine mounted transducer and signal conditioning/data reduction equipment. The transducer must be selected before other system components can be identified or developed. A prototype transducer has been evaluated and proven to meet the above criteria. Its performance has been verified with the use of redundant test methods. This instrumentation included proximity probes, linear accelerometers, an angular velocity transducer and optical methods. The linearity response of the transducer was excellent on all the subjected test set-ups. The device responded equally well to either rotating or non-rotating inputs. Eccentric locations of the transducer were shown to have minimal effects on the output response. Temperature compensation must be built into the production transducer and accurate readings can be expected from 25째F (??.8째C) to 250째F (121째C). The future of this device looks very promising and the range of applications extend from torsional testing and machinery diagnosis to continuous systems monitoring. |
Evaluation of the Acoustic Intensity Approach to identify Transmission Paths in Aircraft Structures | The new two-microphone acoustic intensity technique has been applied to the determination of the transmission paths of sound into an airplane cabin interior. It appears that, provided sufficient care is taken in the measurements, accurate quantitative information can be obtained with this technique on the dominant paths of acoustic energy transmission. This information can be used to make design changes to the fuselage wall to reduce interior cabin noise. |
Brief Status Summary for Automatic Speech Recognition at the start of the 80?셲 | Automatic speech recognition has demonstrated high capability, first in the laboratory and now in field operations. This summary presents the characteristics of today?셲 research and commercial systems, and discusses issues and trade-offs affecting their performance. Independently conducted tests of Dialog System?셲 new speaker dependent, real time continuous speech recognition system demonstrated 99.5% word recognition accuracy in a task with a vocabulary of 10 digits plus 10 control words. The words were spoken by 5 speakers (3 male, 2 female) in a variety of regional American dialects against a background of heavy machine clatter and other noise. |
The Effect of Noise Legislation on Vehicle Diesel Engine Design | Proposals in both Europe and the United States for future reductions in vehicle noise limits can be expected to have radical effects on the design and installation of truck diesel engines. A review of published accounts of quietened trucks shows that mostly engine enclosure has been used. There are short term incentives for manufacturers to use this approach, but it is not the most cost effective solution in the long term and has numerous problems including that of maintaining noise levels throughout the service life of the vehicle. Greater incentive is needed for radical redesign of the diesel engine to make it inherently quiet and to minimise both the on-cost and the energy penalty of noise reduction. This paper develops the theoretical background to this problem. Starting from the basic characteristics of vehicle noise, a philosophy of noise control is developed and practical means of achieving the desired noise control are discussed. |
700 H.P. TRUCK TRANSPORT | SIGNIFICANT REDUCTION IN THE TRANSPORTATION COST PER TON MILE OF BULK PRODUCTS IS ATTAINABLE BY THE PROPER ADAPTATION OF A TRUCK TRAIN TRANSPORT. IMPROVED HAUL ROADS, GREATER DISTANCES, AND INCREASED DEMAND FOR MINE PRODUCTS AT COMPETITIVE PRICES ARE RESULTING IN A RE-EVALUATION OF ALL COST ASPECTS OF MATERIAL MOVEMENT. THE TRUCK TRAIN CONCEPT USING RELATIVELY SMALLER TIRES THAN LARGE PIT TRUCKS OPENS THE DOOR TO REDUCED OPERATING COSTS BY LOWERING CYCLE TIMES AND COST PER MILE OF TIRES AND CAPITAL INVESTMENT. |
Analysis of 30 MPH Frontal Barrier Utilizing Half-Scale Metal Models | A cost-effective early indicator of frontal barrier performance relative to government and corporate goals has been provided by half-scale metal models. These models provide direct indications of steering column kinematics and performance of specific components with respect to the windshield intrusion zone. Some indications of fuel system integrity and windshield retention evaluations have been inferred from half-scale model barrier tests. Model tests have provided early standard barrier data on vehicle crush modes and distances, barrier loads, and deceleration rates, in addition to generating data beyond what is available in standard barrier tests. |
Rollover, Ejection, and the Potential Effectiveness of Restraints in Heavy-Truck Occupant Fatalities | Rollover and ejection are associated with heavy-truck occupant fatalities almost twice as frequently as with passenger-car occupant fatalities. A panel reviewed 41 in-depth cases to assess the possible effectiveness of restraint use and the contribution of rollover and ejection to the fatal injuries. The panel's responses indicated that belt use was expected to be particularly effective in preventing fatalities resulting from occupant ejection. A review of the proportion of ejections by model year indicated that 1972 model year and newer heavy trucks have about 20 percent fewer ejections than pre-1972 heavy trucks. Ejection through the doors was reduced by 80 percent. This difference seems to reflect the effectiveness of FMVSS 206, which required stronger door latches. |
The Basic Design of Two-Stroke Engines | This informative publication is a hands-on reference source for the design of two-stroke engines. The state-of-the-art is presented in such design areas as unsteady gas dynamics, scavenging, combustion, emissions and silencing. In addition, this comprehensive publication features a computer program appendix of 28 design programs, allowing the reader to recreate the applications described in the book. The Basic Design of Two-Stroke Engines offers practical assistance in improving both the mechanical and performance design of this intriguing engine. Organized into eight information-packed chapters, contents of this publication include: Introduction to the Two-Stroke Engine Gas Flow Through Two-Stroke Engines Scavenging the Two-Stroke Engine Combustion in Two-Stroke Engines Computer Modelling of Engines Empirical Assistance for the Designer Reduction of Fuel Consumption and Exhaust Emissions Reduction of Noise Emission from Two-Stroke Engines |
Case Studies Involving the Use and Non-Use of Seatbelts | This paper presents the case study results of several actual motor vehicle accidents which occurred in the western U.S. Each case was analyzed to determine the characteristics of impact to the vehicle and the resulting occupant injuries. The most frequent injury was facial laceration from impacting the windshield. The main benefit of restraint systems lies in their ability to reduce or prevent contact between the occupant and the interior during the crash. |
MF 60 TDL | This paper provides a brief review of some of the more significant features of the new Massey-Ferguson MF 60 Backhoe Loader. The machine incorporates a new ?쐋oad sensing??hydraulic system and a low noise cab. These features together with the basis for its structural design are reviewed. |
A History of Headlining | This paper describes the history of the design and method of installation of cut-and-sew headlining and how it is affected by the design of the body beginning with the all-wooden construction of the first Chrysler up to the present day design. Construction of the headlining listing seam, the drafting procedure for determining their location and trim off around the window and door openings is described. |
A Modular Cab for Farm Tractors | This paper discusses the design of the modular cab for the White Farm A4T tractor. The modular concept creates new problems in cab and tractor design and has a significant effect on tractor assembly line operations. The cab is particularly quiet and well sealed. Data regarding operator noise levels are presented with comparisons shown to similar products and recent legislative activities in the area of noise control. Operator environmental control is improved with the modular concept, and performance data and specifications are discussed. The end product is the result of a close cooperative effort by the tractor manufacturer and cab manufacturer brought forth by the need to provide the customer with a greatly improved cab. |
A Balanced Approach - A Lawyer's Viewpoint | Laws controlling noise and the role of various local, state and federal agencies must be balanced against their respective interests, limitations of technology and environmental goals. Past attempts to control noise sustain the need for a balanced approach. The interest of obtaining realistic, uniform standards which are enforced by realistic, uniform procedures will advance the cause of noise control. Inconsistent standards and enforcement procedures will only impede effective noise control. |
Control of Diesel Engine Exhaust Noise | The contribution of exhaust noise to total vehicle noise is identified by isolation and near field techniques. Control of exhaust noise by using the principles of absorptive, reactive, and dispersive mufflers and their combinations is examined. Guidelines are presented to help the engine designer in the selection of mufflers within the design limitations of size, weight, and engine performance loss. |
Establishment of Roof Rail Sealing Parameters for Automobile Bodies | The reduction of sound levels in modern automobiles has called attention to wind whistles in the body side sealing systems. Methods employed to establish sealing design parameters are reviewed and the primary cause of wind noise in the body side sealing system is defined as a loss of glass-to-weatherstrip contact, produced by door glass ?쐀lowout??in vehicles traveling at highway speeds. A program of controlled dynamic testing resulted in design parameters that have produced body side sealing systems which, together with improved assembly techniques, have increased the first test-run wind noise acceptability rate for 1970 model year vehicles. |
Minimum Noise Pod Design | The necessity for realizing a major reduction in community noise from that produced by the current air transport fleet was recognized at the inception of the design of the Lockheed L-1011 Trijet wide-bodied transport. This paper summarizes the technical considerations and design procedures used to ensure attainment of the low-noise objective. It is shown that the Rolls-Royce RB.211 engine selected for the L-1011 incorporates the latest state of the art noise reduction features, including the novel shaft-slowing provision. These features result in a significant reduction in basic noise level compared to low by-pass ratio engines currently in service, even at the considerably increased size required for the L-1011. The additional noise reduction required to satisfy the low community noise objective and the FAR Part 36 limits is attained by incorporation of advanced noise suppression materials into an efficient propulsion pod design. The technology, design restraints, and system requirements which must be combined into the practical optimum minimum noise pod design are described. |
An Ultrasonic Leak Detector for Automotive Field Service | A wind noise, dust, and water leak detector has been developed for use in the automotive dealership service environment. The detector effectively indicates the precise location of leaks and presents a quantitative indication of the magnitude of the leaks in any body compartment. The new kit embodies a unique application of advanced ultrasonic detection techniques by employing an ultrasonic source and an ultrasonic detector. The device is inexpensive, relatively simple to operate and results in a significant reduction in the manhours required to detect wind noise, dust, and water leaks in automobiles. |
The Case for V/STOL Aircraft in Short-Haul Transportation | The case for a VTOL transport system is presented primarily against the background of European requirements, based on the use of fast low noise fan lift V/STOL aircraft. The main benefits are: 1. Passenger and airline appeal - time saving, convenience, competitive fares. 2. Community acceptance - reduced noise, reduced proliferation of large airports. 3. Operational advantages - flexibility, enhanced all-weather operation, safety and ATC. 4. Reduced investment - on a total system basis. The fan lift formula leads to a wide range of V/STOL aircraft to meet worldwide STOL, V/STOL, and VTOL requirements, with excellent long-term development prospects. |
Legal Aspects of Military Sonic Booms | Sonic booms from aircraft are a relatively recent phenomena. However, the law has developed to meet the new challenges and old rules of liability have been modified to fit the changed conditions. The following paper is an attempt to show some of the legal developments which have resulted from military supersonic flight, since only military or government type aircraft have flown supersonically in the United States to date. Various theories of liability for sonic boom damages have been considered by the courts and these are set forth in this article for comparison purposes. From a review of these decisions, we may be able to anticipate how future courts will handle similar problems. |
Earthmoving Equipment Cab Design | The history of the development of enclosed cab design is discussed. The advent of mechanical power meant that attention could be given to making the equipment operator more comfortable with respect to seating, work space, air conditioning, and visibility. These items are discussed, along with the improvements in rollover protection and noise control. |
On the Noise Reduction of a Rectangular Box with Application to Tractor Cabs | The mechanisms by which airborne sound energy is transmitted into a vehicle cab are discussed. Airborne noise reduction of cabs is seen to deviate considerably from the masslaw behavior of the constituent materials. Various acoustical treatments are evaluated experimentally by directly measuring the noise reduction on a cab-like enclosure. The experimental results agree fairly well with available theoretical methods of computing noise reduction. |
Wax Method of Determining Windshield Defroster Performance | This paper describes a procedure for determining defroster performance using wax. The approach is a useful tool for establishing breakthrough points, and developing balanced defroster air distribution patterns prior to cold room testing. Since it can be conducted at room temperature, the wax method is considerably more convenient and can be executed with greater frequency than in a cold room. Although the wax procedure is a good barometer of the relative effectiveness of different defroster systems, and does provide valuable preliminary studies, it does not duplicate cold room conditions. The test method described, therefore, is not a substitute for, nor can it be used in place of, actual cold room testing. The paper provides information on the test facility, test equipment, test preparation, wax mixture and application, and conducting the test. |
The Objective Method of Evaluating Aspiration Wind Noise | The automobile industry places a major emphasis on reducing car interior noise levels to attain a more pleasant and comfortable ride. In recent years, improved superhighways, allowing higher car speeds, have created a rise in the aspiration wind noise due to high aerodynamic pressure differentials causing air to pass by the body seals. No longer is a car body sealed merely against water leaks. With the increased use of air conditioning in cars, the closed side windows have lowered the ambient interior noise, thereby exposing the broad band frequency aspiration wind noise. A need for an objective method for the quality control and development of body seals was imminent. This report analyzes the aspiration wind noise parameters and presents two objective methods of measuring aspiration wind noise. These methods, using a meter, replace the previously used method of subjective evaluation of the loudness of wind noise. |
Rear Axle Noise Quality Inspection Method | For many years axle plants have needed a practical testing method for rating the noise quality of rear axle assemblies before installation in cars. This report describes the development of such a test method. Creation of noise requires an energy source. The energy source of rear axle noise is the periodic variation in tooth meshing action of the gears. The frequency of axle noise is always related to tooth mesh frequency. A previous study of rear axle gear dynamics indicated the existence of a nearly vertical resonance of rear axle pinions excited by tooth meshing action. The dynamic resonant amplitude of the motion of the pinions related directly to the in-car noise quality of the gear sets. In general, other resonances within the drive line-axle housing-suspension system can be excited by gear action and produce ?쏿xle??noise. An indication of the amplitude of the resonant member (or another responsive member within the system) directly relates to the relative noise quality of the gear set. To verify this relationship, the dynamic pinion response of a group of 30 axle assemblies was measured. The in-car noise ratings were obtained by using a jury of three experienced raters. The correlation between the dynamic pinion motion measured in a test stand and the in-car noise ratings was found to be very good, indicating the feasibility of using this method in axle plants. A statistical analysis was made of the data to determine the degree of correlation and the validity of the data. Details of the test stand operation, noise rating method and tests results are included in the report. |
The Uniflo Personal Rapid Transit System | A personal rapid transit system has been developed, capable of providing urban areas with public transportation service that is competitive with the automobile in speed, availability, accessibility, and comfort. The system contributes no pollution in terms of air, noise, or vibration; it is relatively small in size; and it can be installed elevated, on grade, or below grade. These qualities make it an acceptable addition to a community. Because this personal rapid transit system is highly automated, a significant reduction in the amount of labor required to provide transportation service is anticipated. This could mean that it would again be possible to make money moving people. |
A North European Tractor Cab | A farm tractor protection cab made of thin steel sheet pressings is described. The cab is designed and produced using entirely automotive-type procedures. Curved glasses and a dampening suspension of the glasses are found to be an important means of achieving a low noise level in the cab. Using the pressing technique when producing a steel cab makes it possible to give the various cab details rigidity with a minimum of material. When welded together, these details form a very stiff cab body, which gives the necessary mechanical strength. The curved surfaces, the radii, and the round forms, which from a tooling point of view are natural for pressed steel parts, also have a vibration-dampening effect on the entire cab construction, thus making it easier to design a quiet tractor cab. Mounted on a farm tractor of conventional design, the cab meets the noise rating number ISO N85. |
Door Crashworthiness Criteria | A study of the biomechanical factors concerned with the design of side structures and doors for crashworthiness has been made. Questions regarding optimum stiffness, location of reinforcing members, effect of armrests, and padding have been answered within the framework of injury criteria models. Results of animal studies, cadaver studies, and anthropometric dummies have been combined to produce injury criteria for lateral impacts to the head, thorax, and abdomen. Impacts were applied utilizing a specially designed ?쏿ir gun??in a laboratory environment emphasizing reproducibility and control. Full-scale crash simulations were performed on an impact sled to verify the results of the more specialized tests and analyses. Scaled models of current production doors were used in the animal series. Scaling relationships for various species of animals have been developed and extrapolated to man. Significant differences in right and left side tolerances to impact were noted and detailed. Additional verification of the Maximum Strain Criteria Model (MSC) is reported. Critical impact velocities for various body sites have been developed for several categories of impact and are presented in ways thought to be most meaningful to designers. |
Automotive Safety in Review | This paper broadly surveys the continuing research and development by automotive engineers in designing safer automobiles. Door latch redesign, seat belts, energy absorbing steering columns, laminated windshields, energy absorbing instrument panel and its knobs and levers, dual brake systems, seat back impact absorbing tops, head restraints, and bias-ply tires are among the improvements discussed. Passenger restraint remains the most important factor in saving lives, however, and the public has been careless in using such systems. Passive restraints, such as the air bag, are under development. The need for good driver training programs, the problem of alcohol, and the need for continuing improved highway design are also touched upon. |
Power Plant Design for Noise Suppression | The design configuration of turbofan power plant installations for commercial aircraft is significantly influenced by the requirement for reduced aircraft noise. This paper describes the design evolution of the installation of the CF6, high-bypass ratio engine in the McDonnell Douglas DC-10 as it was influenced by the need for noise suppression measures. The candidate alternatives and the basic trade-off criteria leading to the selected configuration are presented. This paper also includes some considerations associated with choice of material, construction, and design techniques applicable to various areas of sound treatment within the nacelle. |
Noise Considerations in the Design of Advanced Subsonic Transport Turbofan Engines | The problems and choices in the design of an advanced subsonic transport turbofan for reduced noise and improved aircraft performance are examined in this paper. The effects of bypass ratio, fan pressure ratio, and fan tip speed on jet noise, fan noise, and acoustic treatment suppression are described. The results do not indicate a clear optimum bypass ratio considering the effects upon installed engine performance and weight as well as acoustic performance. Low fan tip speed designs with the associated high aerodynamic loading are compared to high tip speed low loading designs. Other factors affecting noise such as the installation and other noise sources are discussed. The long duct installation is indicated to have potential advantages over the short duct separate flow installation. The problem of assuring that growth models of an engine also have low noise is discussed. |
Airtransit's First Six Months of Operating The Canadian STOL Demonstration Service | A complete STOL (Short Take-off and Landing) system is currently providing public transportation service between the urban centres of two large Canadian cities. Passenger and public reaction, plus operating experience in a competitive environment is providing some interesting data, useful in developing future STOL systems as an important component in the improvement of transportation in general. The Demonstration is showing that STOL systems are capable of quickly providing fast, convenient, short-haul service, while at the same time respecting the composite concerns of society, encompassing air-pollution, noise, land-use, energy-consumption and economics. |
Planning, Implementation, and Operation of the Philadelphia-Lindenwold Line | Through careful planning and implementation the Delaware River Port Authority has developed a highly successful mass transit system, the Philadelphia-Lindenwold Line. They have realized their goal of creating a rapid transit line which would win the patronage of potential passengers and be constructed and operated within the economic resources of the Authority. The one to six car trains are operated by a one man train crew who is, in fact, part of the automated or computerized process. He notifies the computer as to the length of the train; opens and closes doors; determines the length in time of each stop; initiates acceleration; and can eliminate station stops. The computer prevailing determines train speed for each track section and right of way conditions; causes the train to decelerate at the optimum rate; and stops at the station with the center of the train at the center of the platform. The Lindenwold Line has demonstrated that motorists will leave their cars if superior transportation is provided; quality transit service can reduce air and noise pollution and conserve energy; traffic congestion can be reduced; technology is now available to create desirable rapid transit service, and that rail rapid transit can be planned, constructed, and efficiently managed to meet operating and maintenance costs out of the fare box. |
NASA REFAN PROGRAM STATUS | The objective of the refan program is to demonstrate the technical feasibility of substantially reducing the noise levels of existing JT8D powered aircraft. The program consists of the design, manufacturing and testing of the refan engines and modified nacelles and airplanes. Experimental testing has been completed for the refan engine both at sea level and at altitude conditions. Ground testing for the B727 side- and center-engine installations and flight testing of the DC-9 with refan engines and acoustic nacelles have been performed. Analyses of the test results are in progress. Preliminary results presented in this paper show that substantial noise reductions were achieved. |
A Technique for Measuring Interior Wind Rush Noise at the Clay Model Stage of Vehicle Design | A technique has been developed to evaluate interior wind rush noise during wind tunnel tests of full-size clay models of vehicles. A small, box-like enclosure with acoustic characteristics made similar to those of a typical vehicle interior is inserted into the clay model behind an actual front sideglass. The wind rush noise coming through the sideglass is directly measured by microphones located within the enclosure. The technique can readily detect wind rush noise changes due to body modifications in the vicinity of the windshield-pillar. In addition, the wind tunnel results agree well with those found on-road. |
Interior Noise Problems of Small Diesel-Powered Buses | This paper discusses interior noise problems characteristic of the combination of diesel engines with typical small bus geometries. One noise problem is the potential for low-frequency resonances. Natural air vibration modes for typical small bus interior dimensions are calculated and shown to give frequencies that can be stimulated by noise and vibration at engine firing frequencies. Measurements of noise and vibration at resonance are given. Other noise problems are associated with internal front engine covers, and leaks and low transmission loss paths in the console area. Some practical suggestions, with examples, are given to reduce interior noise. |
Application of Microprocessors to the Automobile | This paper describes microprocessor technology as it may be applied to the automobiles of the future. The microprocessor requirements described in this paper were generated as a result of the evaluation of the Alpha IV vehicle system which utilizes a solid-state, digital 4-bit, microprocessor to perform several vehicle control and display functions. The development of the Alpha IV system encompassed not only the interface circuit design and microprocessor programming, but also, the derivation of the digital algorithms and control laws for the functions which have traditionally been performed in an analog fashion. The control functions performed include: Cruise Control, Four-Wheel-Lock Control, Traction Control, Speed Warning, Speed Limiting, Ignition Spark Advance and Dwell, Automatic Door Locks, and Anti-Theft System. The display functions include: Speedometer (both analog and digital), Odometer, Trip Odometer, Tachometer, Clock, and Elapsed Time. |
The Rovac Automotive Air Conditioning System | The ROVAC air conditioning system, a new system that employs air as the refrigerant, is a combination rotary compressor/expander unit. A prototype has been modeled, designed, fabricated, laboratory tested, and field tested in a full size four door 1973 Dodge Coronet. The description of the new system, the analysis, design and actual test results are reported here. The objective of the engineering program was to demonstrate and prove the capability of the ROVAC system to effectively and efficiently air condition automobiles. The prototype system installed in the Dodge Coronet produces delivered cooling capacity on the order of one to one and a half tons per thousand rpm and has produced delivered coefficients of performance at relatively high humidity levels (150-180 grains water per pound of dry air) rivaling the best developed conventional vapor compression air conditioning systems. While the present system reported herein has not reached the levels of performance predicted by detailed computer models, continued hardware improvement is facilitating actual performance very near the levels predicted to be practically achievable. During actual in-car jury tests, the prototype ROVAC air conditioning system brings the average passenger compartment temperature from a thermally soaked condition of 107째F down to 72째F in less than two min with five passengers at an average road speed of 30 mph. |
Evaluation of Two Convex Mirror Systems by Government Drivers | A nationwide field study of two types of convex mirror systems was made by the National Highway Traffic Safety Administration (NHTSA) with the cooperation of the General Services Administration (GSA) for a 10-month period starting in January 1974. One convex mirror system, called the Type I system, consisted of a non-adjustable convex mirror on the right fender, the original outside mirror on the driver's door, and a larger inside mirror. The Type II mirror system consisted of an adjustable convex mirror mounted on each fender and the original inside rearview mirror. A total of 515 Federal employees evaluated these two convex mirror systems at six major test locations to provide 627 questionnaires. An analysis of the questionnaires shows that drivers preferred the Type II convex mirror system over the Type I. From comments received, it seems that the drivers objected mostly to the non-adjustable feature and restricted field of view of the Type I system rather than to the fact that it was only a one-convex mirror system as compared to a two-convex mirror system. However, neither convex mirror system was rated as highly as the periscope system was evaluated in a previous field test of 50 periscope equipped GSA automobiles (1)*. This suggests that drivers would prefer unit magnification mirror systems with larger rearward fields of view over convex mirror systems with roughly the same view; nevertheless, drivers also prefer the convex mirror systems tested over conventional mirror systems because the convex mirrors provide greater rearward visibility. |
Acoustic Performance of a Large Semi-Anechoic Test Chamber | This paper describes a large indoor semi-anechoic facility for testing construction machines and discusses the procedures used to determine its acoustic performance characteristics. Data were obtained and analyzed employing controlled pure tone and broad band noise sources with varied microphone distances and elevations. The ground-plane microphone proved to be the most practical way to obtain representative data. Comparisons to an outdoor test site are included. |
J58/YF-12 Ejector Nozzle Performance | The Lockheed YF-12 aircraft uses a blow-in door ejector nozzle, which consists of a variable area, primary nozzle mounted on the afterburner of a Pratt & Whitney Aircraft J58 engine and blow-in doors, a convergent-divergent spool piece, and variable exit area free-floating flaps integrated into a Lockheed YF-12 airframe. Performance data from cold-flow, wind tunnel models and hot-flow, static stand models were correlated and compared with actual flight test data. It was found that these data showed agreement when both internal thermodynamic and external aerodynamic effects were considered. |
Environmental Guidelines for the Designer of Automotive Electronic Components | This paper describes the climatic, dynamic, and electromagnetic environments in which electronic packages must survive at various locations in the automobile. Previously available climatic data is organized to be useful to the designer. New dynamic information that provides power spectral information for various locations on the automobile is presented. The electromagnetic information includes power line transients, voltage regulation, and steady-state noise information. |
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