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Viewing 164041 to 164070 of 183635
1968-02-01
Technical Paper
680491
Robert A. Wolf
The first issues of federal vehicle safety standards, stemming from the Highway Safety Acts of 1966, were directed primarily toward passenger cars. Vehicle safety standards for trucks are now receiving the strong attention of the new National Highway Safety Bureau which initiates the standards. Many of the worthwhile safety countermeasures now being treated by standards have been identified through the process of prior accident research. In view of the emerging emphasis on truck safety the author has reviewed accident research and data collection in the United States in order to summarize the present state of knowledge of accident causation and injury causation related to trucking. Commentary is provided on the potential utility of the existing data as well as the urgent need for new accident research to provide knowledge for guiding the specification of future safety countermeasures.
1968-02-01
Technical Paper
680548
Michael C. Kaye
This paper reports and analyzes the results of drive traction tests using 4 × 2,4 × 4, and 6 × 4 type truck tractors on a skid pad. Traction tests using an automobile and a friction trailer were also carried out on the same skid pad and results are compared. Methods for predicting truck drive traction performance in terms of traction limited grades are presented. Also reported and analyzed are results of hill climbing tests on a steep snow covered mountain grade using triples combinations of 27 ft trailers with 4 × 2 and 4 × 4 truck tractors. Traction limited grades are computed for typical intercity truck combinations.
1968-02-01
Technical Paper
680555
Gordon H. Robinson
Accidents and their causation in man-machine control systems are defined using the automobile and driver as an example. The complex tasks performed by the automobile driver are delineated, and arguments are put forward that the driver’s ability to switch from one task to another, his control of attention, is crucial to the system performance.
1968-02-01
Technical Paper
680545
J. B. Beach
The Lockheed 1011 Jet Transport is designed as a “next generation” aircraft to fill an airline need for a profit-making vehice that will meet the challenges of airline travel during the 1970's and beyond. All forecasts made of this period indicate that todays' commercial transport airplanes will be deficient in payload capability, passenger appeal, airport compatibility, operating costs, and community acceptance, and cannot efficiently meet the demands predicted for air travel growth in the 1970 decade. To provide significant improvements over the present well-advanced jet transports required rigorous evaluation of present and future commercial airline operations. Extensive parametric and design trade-off studies in early stages of the design development produced significant advancements in technology and design for the L-1011. Also featured in the L-1011 are many design concepts developed in consultation with the airlines.
1968-02-01
Technical Paper
680547
Robert E. Nelson, James W. Fitch
The need for operating double and triple trailer combinations has long been recognized. One of the most troublesome questions was braking stability – could longer combinations operate within the same degree of controllability as existing equipment? Stopping performance and stability were studied under controlled conditions of wet and dry roads and various loadings with double and triple combinations. The Utica tests demonstrated that longer combinations, commonly referred to as “double 40s and triple 27s,” when made from properly maintained equipment in current use, achieved braking, stability, and structural integrity characteristics comparable to the shorter combinations – the “single 40s and double 27s.” Modifications to the brake system will improve both stopping distance and stability and allow a greater latitude in loading.
1968-02-01
Technical Paper
680542
John W. Garrett
Accident cases from the Cornell Automotive Crash Injury Research (ACIR) data pool involving 1968 cars are examined to determine whether injury differences exist between these cars and earlier models. Specific design features are reviewed and photographs and descriptions of illustrative case histories are provided. Improvements associated with several new design features are described and several injury hazards observed in the 1968 cars are pointed out. It is concluded that some progress has been made, but further improvement is possible through design change.
1968-02-01
Technical Paper
680543
L. C. Lundstrom
The search for improvements in occupant protection under vehicle impact is hampered by a real lack of reliable biomechanical data. To help fill this void, General Motors has initiated joint research with independent researchers such as the School of Medicine, U. C. L. A. – in this case to study localized head and facial trauma — and has developed such unique laboratory tools as “Tramasaf,” a human-simulating headform, and “MetNet,” a pressure-sensitive metal foam. Research applied directly to product design also has culminated in developments such as the Side-Guard Beam for side impact protection.
1968-02-01
Technical Paper
680529
M. C. Baxter, G. W. Leek, P. E. Mizelle
A 1966 compact van, converted to operate on LP-gas and evaluated under the federal exhaust emissions procedure, approached several definitions of a “pollution-free vehicle.” Specific pollutant results were as follows: 1. The hydrocarbon and carbon monoxide levels of 126 ppm and 0.3%, respectively, were below the 1968 and 1970 emission limits. 2. Certain LP-gas fuel system designs promise to eliminate all evaporative losses. 3. The exhaust hydrocarbons were 70% less reactive than those in gasoline exhaust. 4. Aldehydes, a highly reactive class of exhaust compounds, were low. 5. Oxides of nitrogen were significantly higher with LP-gas because of operation at maximum economy mixtures and maximum power spark advance. 6. The use of a catalytic muffler and rich LP-gas mixtures produced very low oxides of nitrogen levels with other pollutants below the 1968 limits.
1968-02-01
Technical Paper
680538
J. J. Staudt, P. R. Lepisto, J. A. Vitkovits
A technique for evaluating high temperature oxidation and corrosion tendencies of automotive crankcase lubricants is described. The technique utilizes a versatile bench apparatus which, with a minimum of modification, can be used for either evaluating thermal oxidation stability of gear lubricants or oxidation-corrosion tendencies of automotive crankcase lubricants. The apparatus is relatively compact and requires a minimal lubricant sample. Design of the apparatus permits close control of all operating parameters and provides satisfactory test data repeatability. Retainable copper-lead test bearings are used as the indicator in predicting a pass or fail of fully formulated crankcase lubricants as in the case of the CRC L-38-559 (Federal Test Method 3405) technique. Engine and bench test data are compared to illustrate the capabilities of this new bench technique.
1968-02-01
Technical Paper
680639
Leon Marcus, Frank M. Anthony
The feasibility of using ceramic materials for advanced airframe and propulsion system structural applications has already been demonstrated. However, their effective use is limited by their relatively high variability in strength. Although it is known that a large number of factors influences the strength of ceramic materials, in the two ceramic composite systems studied here, ZrB2-SiC-B4C and C-ZrB2-SiC, it was apparent that each system had its own strength controlling parameters. It was found that the strength variability could be noticeably decreased by incorporating two engineering techniques: (a) material selectivity, and (b) proof testing. It is shown that at the low probability failure rates normally associated with airframe structure design allowable strengths can be approximately doubled.
1968-02-01
Technical Paper
680638
Frank Jaques
Synchronized pulsed flushing is described as a method for controlling wear on electrodes during the EDM process, which uses electrical energy to remove material in machining. Background is provided on EDM phenomena. The attributes of wear are specified, and the method of synchronized pulsed flushing is contrasted with continuous flushing.
1968-02-01
Technical Paper
680636
Earnest Y. Seborg
Multiple lead enables electrical discharge machining to compete as a production method with conventional machining methods, provided proper tooling is used. In this paper, the electrical discharge power supply, the machine, the work and electrode holding fixtures, the electrodes, and the dielectric are all considered as tools. Each has its individual function in obtaining an efficient EDM cut which is essential for multiple-lead operation. The power supply must be capable of producing discharges that are compatible with the electrodes and workpieces being used. Machines must furnish the servo function and auxiliary cycling equipment. Work and electrode holding fixtures must hold precision relationship between electrodes and workpieces as well as eliminate electrode vibration and direct dielectric flow. The electrodes must be suitable to the application, and because they are expendable, must be economically produced.
1968-02-01
Technical Paper
680635
Terry O. Hockenberry
The dynamic behavior of the dielectric fluid and fluid contaminants, and some of the effects of the dielectric fluid behavior on the electrical discharge machining process variables are described. High speed photomicrographic records showing the dispersion of debris accompanying a single EDM discharge and the removal of the debris by the dielectric fluid flow are presented. Dielectric flushing effectiveness is discussed and curves of volume flow rate for deep cavities are presented. The volume flow rate data suggest that dielectric flushing pressure, the flushing parameter which is usually monitored during the EDM process, is not a very meaningful indication of flushing effectiveness.
1968-02-01
Technical Paper
680621
K. V. Johnson
SAE J987, Crane Structures - Method of Test, has made several contributions to stress analysis by distinguishing between different kinds of stress areas, standardizing the conditions of test, prescribing acceptable stress levels for duty cycles expected, and standardizing the recording of data. This paper discusses the testing of a 65 ton truck crane frame in accordance with the test procedure, including placement and number of gages, endurance life, and analysis of data.
1968-02-01
Technical Paper
680600
James T. Sykes, Lloyd C. Newland
It is one thing for an engineer to design the safest vehicle and equip it with the most effective restraint system. It is quite another to have the user of this fine equipment use it to lengthen his own life. This paper explains the process one segment of a large government agency has successfully used to get approximately 88% use of the restraint system on the job and a slightly lower percentage of use by employee's families in the family car. Program emphasis has been on the 3-point lap/shoulder belt for maximum head protection.
1968-02-01
Technical Paper
680591
G. S. Haviland
A review of benefits to be gained by automatically controlling the slip properties of truck tires indicates that up to 40% shorter stops and complete jackknife control when braking is possible. A simple all-mechanical device is described for use with air brakes which, from the data, shows 7-30% shorter stops, no tire degradation, and full steering control. Data is presented from full sized semi-trailer truck skid tests.
1968-02-01
Technical Paper
680565
Donald G. Hubbard, John A. Demcak
An operating system of automatic data acquisition and on-line computation as used in general engine testing is discussed. The considerations for its configuration are developed and operating history is reported. Included in the discussion are the parameters guiding the design of the system, method of operation, data format, and operating costs. An engine performance computer program is also outlined.
1968-02-01
Technical Paper
680650
J. L. Showalter
The established parameters for hot forming cross-rolled beryllium sheet have been expanded to incorporate advanced configurated structural components and production details during the last year. Tooling, forming equipment, and forming techniques have been improved to fulfill these requirements. Experimental conical sections, drawn cups and hat sections have been formed. Production circular frame caps, stiffeners, splice plates, and curved channels have also been produced. Hot-forming tooling has been utilized in furnaces, hot-forming presses and hydraulic presses to form these details. The forming of the production parts has produced over-all manufacturing cost data reflecting material costs, tool design and fabrication costs and cost of forming. Conclusions and recommendations for future work have been made concerning the effects of forming parameters on material properties and for improvements in tool designs, equipment designs and forming techniques.
1968-02-01
Technical Paper
680649
Bill Purdon
This paper presents advanced methods, procedures, and techniques for the chemical and mechanical machining of beryllium based on the writer’s personal experience and information he has accumulated from the Beryllium Industries’ fabrication experience. Machining techniques included are chemical milling, electrochemical milling, electrical discharge machining, milling, drilling, turning, tapping, grinding, band sawing, and burring.
1968-02-01
Technical Paper
680648
J. S. Bleymaier, Milton Weiss
Beryllium offers many advantages in aerospace applications. However, its brittleness, notch sensitivity, high cost, and difficulty in fabricating have limited its use to date. This paper discusses these problems in detail, along with applications in which these disadvantages can be overcome. The peculiar properties of beryllium can be utilized to advantage if the system is weight critical, thermal expansion sensitive, or subject to high loadings at high temperature. Other areas are when the structure is deflection critical or the packaging volume for erectables is limited. In these areas, the metal can be utilized successfully if the loads are well defined, the design avoids brittle fracture, no impact loads are encountered, and redundant structure design is possible.
1968-02-01
Technical Paper
680646
Alberto Alvarez-Calderon
The purpose of this paper is to present principal aerodynamic characteristics of inverting flaps as determined in test flights and wind tunnel tests, and to review applications of this new device, and of its basic kinematic principle, to the V/STOL aircraft field. Two dimensional tests of double slotted inverting flaps show maximum lift coefficients of over four. Flight tests and three dimensional tunnel data show exceptional aerodynamic features for the new flap, including favorable lift-drag ratio and moment characteristics for high lift 90 deg flap position in approach and landing, and direct control of lift-drag ratio with flap position particularly advantageous for wave off and loiter. General considerations on mechanical, structural and operational aspects are reviewed.
1968-02-01
Technical Paper
680644
Jerry P. Barrack, Jerry V. Kirk
Considerable research on large-scale high-performance, lift-engine, V/STOL configurations has been conducted at Ames Research Center. The exhaust gas reingestion characteristics, lift-engine inlet total-pressure recovery and distortion, and engine-airframe induced effects were measured in the 40 × 80 ft wind tunnel both in and out of ground effect over a wide range of transition flight conditions. The results of these investigations show that the lift-engine configurations studied may have severe operational constraints placed upon them during transition.
1968-02-01
Technical Paper
680643
James N. Krusos
Analytical and experimental evaluations were made of the potential of porous ceramics for use as re-entry vehicle heat shield materials. Significant potential is foreseen though further advances in structural and material technologies are needed to realize fully the advantages offered by stable high temperature materials. The experimental work suggests that brittle fracture propagation, highly critical in dense ceramics, is less of a problem with porous ceramics.
1968-02-01
Technical Paper
680642
K. E. Weber, D. S. Cowgill, J. S. Fritzen, S. Krystkowiak
The morphology of salt water stress corrosion cracks in 8A1-1Mo-1V titanium alloy has been determined. In the interior of the specimens the cracks are brittle in nature and far more extensive than indicated by cracks visible at the specimen surface. The direction of propagation of the internal cracks is away from the plane of the specimen starter crack. These crack characteristics are explained in terms of internal stress state and presence of contaminants containing chlorides.
1968-02-01
Technical Paper
680641
R. Johnson, S. J. Kong
A summary is presented of the work conducted during the first 18 months of a 36 month research program to investigate the structural utilization of oxidation-resistant dispersion-strengthened (DS) metals. Dispersion-strengthened metals having the potential for structural use in an uncoated form at temperatures up to 2400 F had previously been developed in material research programs, and the current program was initiated to investigate their use in structures that will experience repeated service at elevated temperatures.
1968-02-01
Technical Paper
680414
W. W. Crouse, B. N. Koelsch, W. D. Preston
Oil economy is the one quality of a new engine oil that can be most readily observed by the customer. Studies have been made of the relative oil economies of a series of test oils using three different testing environments. These were laboratory engines, a tire test fleet, and an 80 car employee fleet test. All three methods generally ranked oils in the same order, but the size of the differences varied somewhat from method to method. These tests were then used to demonstrate the effects viscosity index improvers and detergent-dispersant packages have on the consumption characteristics of engine oils. They showed that increasing the concentration of viscosity index improvers did not return a proportionate improvement in oil economy. Simple reblending of older multigrade oils to meet the new SAE requirement for measuring the oil’s viscosity at 0 F may result in an oil with significantly poorer economy.
1968-02-01
Technical Paper
680415
R. M. Stewart, C. R. Spohn, W. A. P. Meyer
Factors contributing to winter hot starting difficulties encountered in some modern automotive gasoline engines were investigated in a two-phase study. These factors were evaluated first in test cars and then in a test stand engine under more closely controlled laboratory conditions. The effect of oil viscosity on an engine's hot cranking torque requirements and the ability of batteries at various charge levels to supply sufficient power to satisfy these requirements were extensively investigated; whereas the effects of viscosity index improvers, precombustion reactions, engine hot soak time, and oil temperature were only briefly investigated. The present ASTM D 445 viscosity at 210 F was shown to be inadequate for predicting the hot cranking performance of multigrade oils and a method for determining an oil's hot cranking “engine viscosity” was developed.
1968-02-01
Technical Paper
680417
M. G. Jacko, W. M. Spurgeon, R. M. Rusnak, S. B. Catalano
Automotive brake linings are complex composites of organic resin binders, asbestos fiber reinforcement, and property modifiers. Brake lining fade is believed to be due in part to gas evolution from pyrolysis of these components at the lining-drum interface. Differential thermal analysis, thermogravimetric analysis, and X -ray diffraction have been applied to the study of pyrolysis of these typical ingredients and the composites (linings) made from them. The relation between thermal decomposition of the lining components, the linings themselves, and fade in drag dynamometry is discussed. The final performance evaluation of friction materials with respect to fade characteristics can only be obtained from extensive qualification tests carried out on vehicles, one reason being that the true temperatures of the linings at their sliding interfaces with the drum are not known.
1968-02-01
Technical Paper
680418
R. W. Hurn, W. F. Marshall
Methods used in diesel emissions measurement at the Bartlesville Petroleum Research Center are described; limitations, adequacy, and needs for further development of each are discussed. Smoke measurements are reported from work with the Hartridge meter, as well as newly developed instruments that are used to view smoke plumes directly, and which seem to offer advantage over smokemeters previously used. Experience in odor assessment by a human panel using reference odor materials is reported as encouraging. Odor intensity is judged with much greater reliability than odor quality; capability to assess the latter remains wholly inadequate. Results in application of the methods for measuring diesel emissions are intended to illustrate the use of experimental techniques to reveal engine and fuel factors as they influence the character, amount, and air-polluting effect of diesel emissions.
1968-02-01
Technical Paper
680401
R. F. Sawyer, E. S. Starkman, L Muzio, W. L. Schmidt
A single cylinder investigation was conducted to determine concentration of oxides of nitrogen resulting from combustion of ammonia and air in a spark ignition engine over a range of fuel-air ratios typical of normal engine operation with ammonia. Nitric oxide concentrations exceeded that with hydrocarbons. Spectroscopic observations during the expansion process gave concentrations in some instances an order of magnitude greater than exhaust gas determinations. The results imply a different mechanism for nitric oxide formation with ammonia fuel than with hydrocarbons and that some equilibrating process may take place between combustion and exhaust to reduce otherwise even greater than measured exhaust gas concentrations.

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