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1974-02-01
Technical Paper
740217
R. B. Thakkar, K. G. McConnell
A new theory was developed to obtain an exact sinusoidal simulation of material fatigue life when subjected to a gaussian narrow band random loading. The theory was based upon duplicating the probability density distribution of peak amplitudes that is Rayleigh. An experimental investigation was conducted to obtain validity of this theory. The fatigue lives obtained under the two types of loadings compared within 10%. The statistical probability density distribution of input and output acceleration processes for both types of loading compared very well. It is believed that the approach of the theory described herein can be applied to any real loading time history where the probability density distribution of the actual field service peak amplitudes is known.
1974-02-01
Technical Paper
740219
T. J. Flis, F. B. Cupp
A high-packing-density digital tape recorder has been developed for long-term mobile recording of low-frequency analog input data. The recorder operates unattended directly from the car battery and offers significant advantages over conventional FM instrumentation tape recorders in size, power, weight, channel count, and record time. A separate playback unit enters the digital data directly into a computer for analysis, and provides an analog reconstruct of any one of the input channels for graphic analysis. The recording system is discussed with the aid of a functional block diagram, and samples of reconstructed data from actual road tests are presented to illustrate the performance of the recorder in a severe shock and vibration environment.
1974-02-01
Technical Paper
740221
W. R. Brose, N. E. Dowling, JoDean Morrow
Data are reported for smooth specimens of SAE 4340, RQC-100, and Man-Ten steels subjected to constant stress amplitude cycling below the conventional fatigue limit. The presence of occasional large strain cycles, or overstrains, in the history resulted in finite lives. Possible causes of this effect are discussed, and it is shown that the deformation response of these steels is altered by overstrain. Inelastic strain-life data for the periodic overstrain and initial overstrain tests fall on the same line in a log-log plot that represents the nonoverstrain tests at shorter lives. The use of inelastic strain as a fatigue damage parameter is discussed.
1974-02-01
Technical Paper
740422
Sher Temkin
A practical approach to the ferrous die cast process was initiated by a research and development team at General Electric Co. The team studied the feasibility of casting ferrous metals under pressure into permanent metal molds. Detailed here is the method, castable shapes, properties, and what alloys can be cast, as well as its economic advantages.
1974-02-01
Technical Paper
740415
S. K. Rhee
Commercial “organic” friction materials were obtained from three different manufacturers, and were evaluated for their frictional properties. In all cases, the friction force (F) was found to be a power function of the normal load (P) and sliding speed (V) at a fixed temperature, F = K·Pa·Vb at T1, where K is the coefficient of friction which is constant and independent of the load and speed, and a and b are one set of parameters at the temperature T1. Usually, the exponent a ranges 0.80-1.25 and b from -0.25 to +0.25, depending upon the temperature. Thus, brake torque becomes a power function rather than a linear function of the line pressure. Brake fade is found to be governed by the three mechanisms-load fade, speed fade, and temperature fade.
1974-02-01
Technical Paper
740423
Paul R. Thomas, Ronald H. Till
A method for measurement of rolling resistance of vehicles using only a single accelerometer measurement has been developed and a simple instrument has been constructed. Results of typical measurements on large, electrically propelled off-highway trucks are discussed.
1974-02-01
Technical Paper
740004
Charles S. Davis
This paper, through example, illustrates the use of the finite element method in analyzing automotive components. NASTRAN, the large-scale, general-purpose digital computer program based on the concept of finite element was used for predicting structural behavior. Each example is discussed in sufficient detail to describe the general finite element analysis procedure.
1974-02-01
Technical Paper
740015
Robert B. Hood
This paper is an introductory survey or sensors, displays, and signal processors of potential value to automotive control designers. The sensors section discusses position sensing, pressure sensing, and temperature sensing. The interface section discusses general use semiconductor signal processor-to-sensor interface components and single chip subsystem components. The displays and interface elements section covers standard digital displays and the interface elements required to dirve them. The paper makes a case for the ultimate success of “combinational components” which are defined as single chip components that combine the sensor and interface circuit.
1974-02-01
Technical Paper
740021
Howard Weber
To improve engine performance, reduce air pollution, and increase spark plug life, electronic ignition redesign may be necessary. This report covers the advantages and some of the practical limitations that can be involved in electronic breakerless inductive storage ignition design. Basic principles such as dwell control are examined in detail. Specific conclusions regarding Darlington coil-switching transistors and current-limiting vari-dwell ignition circuits are drawn.
1974-02-01
Technical Paper
740151
E. L. Cline, W. C. Wickersham, Frank W. Hartman
The results of an investigation of the relationship between course deviation and quantified brake faults are presented in this paper. The development of chassis dynamometer brake testing criteria, correlated with road test and physical inspection results, is discussed. Statistics on the prevalence of in-use vehicle brake system faults are given. The improvements in perception and repeatability enabled by computer automation of the dynamometer brake tester are described.
1974-02-01
Technical Paper
740106
William H. Close
Decisions have been made regarding the federal regulation of noise generated by motor carrier operations which are subject to the provisions of the Noise Control Act of 1972. This paper presents a brief discussion and analysis of the technical information developed by the interagency task force and public docket, which was made available to the government for development of a regulatory strategy. Substantive research is underway to ascertain the technology and cost involved to significantly lower the engine-related and tire noise generated by trucks.
1974-02-01
Technical Paper
740115
PETER WARNER
The British Government D.O.E. T.R.R.L. awarded a contract to David Ogle Ltd as part of their E.S.V. programme, to develop a lifelike, simple, robust and repeatable dummy. This paper relates the interim design and test results.
1974-02-01
Technical Paper
740117
Stanley H. Backaitis
The sensitivity of response of crash victim simulation was investigated using a two-dimensional, mathematical eight-mass model. The model was exercised in the forward collision mode in a three-point restraint system using a trapezoidal forcing function. Mass and inertia parameters of the occupant simulation, its setup, and the restraint and environment systems were evaluated individually and as groups, in terms of their effects on the occupant's head and chest acceleration. The study also investigates and rates the effects of shape and time duration of the forcing function upon the response of the occupant.
1974-02-01
Technical Paper
740122
A. G. Urlaub, F. G. Chmela
The L9204 FMV engine developed by Maschinenfabrik Augsburg-Nürnberg AG (M.A.N.) is an air-cooled, 4-cyl, in-line unit with remarkable multifuel capabilities. With a displacement of 162 in3, it is rated to produce 70 hp at 3800 rpm. The use of the FM combustion system, in addition to conferring multifuel ability, has made it possible also to achieve a high power/weight ratio. This paper presents details of the engine design and operating data, and results of endurance testing are given.
1974-02-01
Technical Paper
740073
K. L. Oblizajek, S. A. Lippmann
A method is derived and confirmed for predicting the tread wear configurations of tires positioned on nondriven axles of passenger vehicles. The method is based on laboratory measurements of the interfacial stresses of freely rolling tires and takes account of perturbations in these stresses that occur during the road test procedure. Wear is found to occur primarily at the exit end of the tire-road interface, and the degree of wear is related to the interfacial pressure and slip determining conditions at that location. The steering properties of the tire also enter into the determination. Abrasion resistance of the rubber, temperature, character of the road surface, the test course, and the procedure all appear in the equations of wear in aggregate as a coefficient. In addition, there are interference effects between adjacent ribs of the tire that are established and taken into account.
1974-02-01
Technical Paper
740067
William Bezbatchenko
A vehicle test procedure for determining the effect of bias, belted-bias, and radial tires of different designs on constant speed fuel economy was devised. Test results were analyzed on a statistical basis. Results at a 95% confidence level indicate that the use of steel belted radial tires decreases the fuel consumption approximately 6% when compared to bias and belted-bias tires.
1974-02-01
Technical Paper
740077
W. A. Anderson, R. D. Blackburn, B. S. Shabel
A study has been made of the various alloys for body sheet. These include the non-heat-treatable Al-Mg alloys and heat-treatable alloys of the Al-Mg-Si and Al-Cu-Mg types. Tests have shown that each alloy has a different combination of properties with no alloy excelling in all characteristics. At this stage in the development of aluminum body sheet, it would appear that the Al-Cu-Mg alloys 2036 and X5020 should be preferred over other types for general body sheet application. Where Lueder bands can be tolerated, Al-Mg alloys such as 5182 and X5085 offer an advantage of superior formability and are recommended for use as inner stiffening panels and supports.
1974-02-01
Technical Paper
740098
Paul Tartaglia
The various methods available for proximity measuring are described and evaluated, resulting in the choice of radar as the best method available. Radar does have its drawbacks, however, and its major liability is the production of a possible health hazard in the form of microwave radiation. Limits imposed by the U.S. government are presented and compared to values obtained from a proposed system.
1974-02-01
Technical Paper
740094
John B. Flannery
Braking system, developed by AutoStop Corp., uses doppler-generated signals to reduce stopping distance of vehicle in danger of collision. Safety device acts on conventional controls of vehicle, provides backup where driver's reaction time is not adequate, and rapid deceleration is required to avoid collision. Actuation of controls to achieve deceleration is accomplished by two vacuum bellows, one mechanically linked to the brake pedal, another linked to throttle and accelerator. Braking action is initiated by driver. System discriminates between objects which present danger of collision, and false targets such as traffic in adjacent lanes and signposts.
1974-02-01
Technical Paper
740658
Jack Poley
This paper describes how a comprehensive oil analysis program is implemented in operations involving off-highway and similar equipment. Oil samples are taken on a routine basis and thoroughly analyzed in a laboratory. Tests are tailored to the equipment being sampled, and individual records are maintained per unit to allow monitoring of trends. Highly qualified data analysts review test results and provide practical maintenance recommendations. The result is an improvement in reliability, reduced downtime, and the direction of repair efforts only when and where necessary. Test significance and interpretation are discussed and exemplary case histories provided.
1974-02-01
Technical Paper
740526
Thomas E. Ritter
Several techniques have been developed to measure the relative amount of splash and spray produced by vehicles when driven on wet roads at highway speeds under controlled conditions. This paper discusses considerations in the development of measurement techniques such as those utilizing photographs, a photometer, densitometer, spraymeter, and spray collector. The development of each technique is described. Some test data utilizing the photometer and densitometer techniques are presented in a comparison of two different trucks run on two different road surfaces with new and worn tires, fully loaded and unloaded, and under light and heavy road moisture conditions.
1974-02-01
Technical Paper
740534
H. B. Rath
Vehicle diagnostic systems have been proposed which are based on the interrogation of a series of sensors located at critical points of the vehicle by an automatic check-out device which is a part of the service shop equipment. At least one system of this type already is in use on an imported passenger car. Systems also are in existence which provide a series of alarms to warn the operator of certain off-normal conditions which may occur during daily vehicle operation. Many off-normal conditions thus alarmed may never be reported because they are of a momentary or intermittent nature. This type of condition rarely can be detected by means of a checkout on the floor of the service shop. The diagnostic system described monitors off-normal conditions as they occur during day-to-day operation and provides a record of them for use by maintenance people. The simplest form of the system provides only a count of the number of occurrences.
1974-02-01
Technical Paper
740560
L. L. Hartter, H. W. Schwartz, S. K. Rhee
Past work has shown that brake discs constructed of a copper alloy containing 1% chromium can significantly reduce temperatures at the sliding interface. The purpose of this investigation was to demonstrate this fact further, and specifically to determine how copper discs should be configured to provide desired temperature response with a minimum amount of material. To accomplish this objective, an analytical thermal model was developed of a disc design for heavy trucks. The model employed the finite difference approach, in which the disc was subdivided into a number of small volumes. The model specifically simulated disc temperature response during 50 mph fade tests performed on a dynamometer. The thermal model was correlated with test data to verify and improve its accuracy, and then utilized to evaluate the effects of material and geometry changes.
1974-02-01
Technical Paper
740552
R. Heimbuch, F. Schierloh
Several new HSLA steels have become commercially available over the past year. The materials were introduced with inadequate data describing their properties, even though they differed from conventional 1008-1010. This paper specifies a list of material characteristics which are needed in selecting these new HSLA. The list includes design properties, manufacturing properties and commercial factors. Laboratory tests are specified for measuring the properties of interest.
1974-02-01
Technical Paper
740568
Ulrich N. Wanderer, Heinz M. Weber
For one year now, an interdisciplinary team (engineers, physicians and a psychologist) has been working on an analysis of accident occurences, in Hannover. The accident causes, proceedings and consequences should be analysed by as precise and accurate methods of data acquisition as possible on the scene of the accident. First results show that only 36% of the accident causes could have been avoided or at least reduced. The remaining 64% of the accidents were based on human failings which cannot be changed or only changed with great difficulty. The analysis of accidents involving pedestrians showed that the more serious injuries were due to the impact with the vehicle and not the road surface.
1974-02-01
Technical Paper
740685
Walker H. Flint
The unaltered, commercially available instrumentation described in this paper provides an accurate (close to Type 1 sound level meter tolerances) and lightweight (total system-5.25 lb) sound recording system. In conjunction with commercially available programable calculators, this instrumentation enables accurate determination of dosage to various criteria. The applications include construction equipment, lift trucks, farm or yard tractors, private airplanes, military vehicles, highway trucks, motor boats, snowmobiles, etc.
1974-02-01
Technical Paper
740967
Narendra J. Sheth, P. Scott Gegesky
As the compliance with noise legislation became more difficult, Ford exhaust system development engineers increasingly encountered variances not only from vehicle-to-vehicle, but on the same vehicle tested in different locations. As a result, a series of tests were conducted to establish the correlation among various sites for vehicle exterior noise measurements. The purpose of this paper is to present the results and the method developed to achieve the correlation in terms of the following: 1. Ford and site equipment differences 2. Driver differences 3. Differences between site physical qualities Seven sites were evaluated in the program where seven vehicles were used with a good spread in exterior noise levels. A representative correlation plot is also presented which can be used to predict the expected noise level of any vehicle at any one of these test sites knowing the level obtained at the Ford site.
1974-02-01
Technical Paper
740968
John F. Hemdal
The sound pressure level (SPL) measured at a given point varies as a motor vehicle goes through a pass-by noise test such as SAE J986a. The tests described in this paper were intended to assess the magnitude and variability of different motor vehicle noise measurements. All factors which might cause variation in the received SPL were either controlled or monitored. This study was designed to quantify the effects on SPL from wind turbulence.
1974-02-01
Technical Paper
740962
Norma D. Miller, Dwane Baumgardner, Rudolf G. Mortimer
This paper presents the results of a study directed toward examining the effects of glare resulting from following headlights reflected in rearview mirrors. In particular, the effects of different driving environments are discussed with regard to their effects on glare. The results of a computer analysis predicting the magnitude of glare reflected from rearview mirrors for several headlight systems are also presented. These computations cover a range of intercar spacings and both inside and outside mirrors. An important question is also posed concerning the effects of glare in a driver's peripheral field-of-view and its potential effects on the detection of early warning events.
1974-02-01
Technical Paper
740964
R. R. Mourant, R. J. Donohue
Driver behavior in obtaining information through rearview mirrors and head turns was analyzed for novice, young experienced, and mature drivers during daytime driving on a freeway route. No significantly different mirror sampling patters were obtained when the horizontal fields of view of the plane left side and inside mirrors were expanded by approximately 25%. Some difference in behavior did occur between the mature and the other drivers, especially in mirror use when driving straight ahead. The total time to obtain information for left merges was significantly larger than for left and right lane changes and a right merge. Finally, the time required to obtain information to make a decision for a left or right lane change without execution was considerably less than the time needed when the maneuver was actually executed.
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