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This paper outlines the nature of the measuring equipment used in the investigation of tire-road interactions and presents the results of a study of the interfacial stress distributions of a radial-ply, a bias-belted, and a 4-ply bias-angle tire. There is a discussion of tractive ratios and effective coefficients of friction. Distributions of tractive ratios are displayed for all of the conditions treated and for the three types of tires. The paper also covers the changes in stress distributions that result from steering and the relation of these alterations to the lateral thrust and self-aligning torque of the tires.

This paper discusses how fiber orientation of fiber in fiber- reinforced plastics affects automotive applications. Orientation can adversely affect moldings in applications where stress is important, especially in engine components such as front timing covers, pump flanges, oil sump bosses, and crankshaft housing. The paper examines these problems in detail and suggests ways to avert serious difficulties relating to fiber orientation. (AN)

This paper discusses the cornering characteristics during the progress of tire wear and how the stability and controllability of a vehicle varies in the various stages of tire wear. With the introduction of tire parameters appropriate to represent the characteristics of tire construction, the method of calculation of the cornering characteristics of a tire is proposed in this paper. Furthermore, this paper shows the values of tire parameters in the various stages of tire wear in both cases of bias belted and radial tires.

The frequent use of copper‐lead and cadmium alloy bearings for heavy duty diesel engine use has brought about a number of problems and a lot of troubles that occur with these bearings are frequently blamed on to the lubricating oil. The difficulty of differentiating between failures caused by fatigue and corrosion is a real one and quite apart from these two causes, there may be many contributory factors. A paper recently presented to the Society of Automobile Engineers at California by Mr. Stokely of the California Research Corporation on this subject has provided some valuable guidance on these matters. The following is a condensation of this paper.

This paper discusses the development of adequate criteria and evaluation methods for seat belt restraint design. These criteria should include the effect of seat belts in abdominal injury as well as head injury. It is concluded that belt load limiters and energy-absorbing devices should limit head-to-vehicle contact, ensure that the lap belt maintains proper contact with the bony pelvic girdle, and limit the belt loads. Studies are made of pulse shape and belt fabrics. Currently available mathematical models are used for the studies included in the paper.

In this paper, originally published in 1974, an electromagnetic detection scheme for automotive precollision sensing is described. The scheme is called BAseband Radar Bag Initiator (BARBI). The proposed technique involves the transmission and reception of a subnanosecond baseband or video impulse-like signal. It requires virtually no microwave components. The very fast signal risetime permits leading edge resolution on approaching vehicles of much less than a foot. Closing velocity is obtained by using range-rate techniques. By incorporating sequential range gating techniques, the false alarm rate can be significantly reduced. The BARBI system presents a fresh approach for a high resolution and inexpensive sensor with few of the problems of conventional systems. An extension of this technique is also suggested for braking applications.

The objective of this paper is to illustrate an interactive computer graphics program developed to simplify the creation of finite element data which will be used for computerized structural analysis. Three-dimensional, part definition data in the form of basic design lines in input to the program and displayed on a cathode ray tube, and then a structural engineer creates the finite element definition using various computer graphics techniques. The procedures involved are discussed in detail, as well as the advantages over the traditional manual approach to element generation.

This paper discusses: fuel economy -- definitions, measurement, testing, and passenger car trends; emission control interaction with fuel economy -- emission regulatory progression, engine factors, fuel economy at several emission control levels, and emission compliance; and catalytic converter -- basis for GM decision, unleaded gasoline, GM catalytic converter system, and the yet unregulated emissions. For the mid-1970's, catalytic converter systems provide the best compromise accounting for all considerations.

This paper deals with some work currently being carried out at the Lucas Group Research Centre into the control of vehicle headway using Q-band primary radar. Earlier work is described in which a "sawtooth" frequency-modulated continuous wave radar system and analog controller were fitted to a Ford Zodiac with automatic transmission and used to investigate the viability of such a system. This is compared with later work in which a miniature radar of improved performance and a digital microprocessor control system are fitted to a Triumph 2.5 PI. The latter approach is enabling several types of control law and radar modulation parameters to be tried so that the overall ability of primary radar systems to cope with varying road conditions can be ascertained.

This paper presents preliminary results of studies of the feasibility of applying electro-optical diagnostic techniques to diesel engine research. A 2-cycle, 3-cyl, diesel engine was modified by installing quartz windows in the combustion chamber to provide optical access. Techniques investigated include photography, holography, laser resonance absorption spectroscopy, and laser velocimetry. Droplet formation, breakup, and combustion can be observed in the combustion chamber in three dimensions using holography. The same hologram can be used for particle sizing and flow visualization studies. Formation of certain hydrocarbons can be observed in real time with resonance absorption, using a tunable He-Ne laser.

The paper describes a new passive restraint system, the Volkswagen Restraint Automatic (VW-RA). The system consists of an upper torso belt and an energy-absorbing knee bolster. The operation of the system is automatic as it is attached to the door of the vehicle. The comparison with the three-point belt having a vehicle-sensitive locking retractor and airbag systems shows that the overall performance of the VW-RA is superior to the other systems. A fleet test of 50 vehicles in the United States will determine acceptability to the consumer.

This paper is a general discussion of the basic circuit design techniques used in monolithic linear integrated circuits. Basic diode and transistor circuit behavior is defined, and basic general purpose circuits characteristic of monolithic designs are analyzed. These circuits include current sources and mirrors, differential amplifiers, d-c level-shift circuits, Darlington gain blocks, and output stages. The discussions are summarized by an analysis of a simplified CA741-type operational amplifier design.

This paper summarizes the progress to date on a program sponsored by the U. S. Environmental Protection Agency to develop an automobile Rankine engine employing water as the working fluid and a 4-cyl uniflow reciprocating expander. Design details of the system are presented including a description of major components and packaging arrangements of the system in a six-passenger car. Results of development testing to date are presented illustrating that the exhaust emissions are well below the current 1977 federal standards.

A number of salient vehicle cost factors upon which the truck automatic transmission has an impact are discussed -- along with the transmission design principles which lead to that impact. In addition, this paper gives indication of forthcoming refinements in transmission design which will further reduce fuel consumption costs.

This paper describes two instruments for electronically controlling ignition timing that were developed for the investigation of ignition timing control surfaces. The first instrument described generates straight-line advance and engine speed. The second instruments described is more versatile and allows the generation of advance curves that are a general function of two independent variables, one of these being engine speed.

This paper identifies and analyzes steady-state and transient tire properties affecting vehicle directional response characteristics. The study is limited to the relationship between lateral force and slip angle. It shows fundamental differences between steady-state and transient properties. An interrelationship between cornering stiffness and dynamic lateral force offset resulting from the time lag between lateral force and slip angle is shown. Rapm steer techniques for measuring transient tire properties on a road trailer and on an external drum machine are described. A need for transient tire data for computer simulations of vehicle transient steer maneuvers is shown. Subjective evaluations of a vehicle equipped with different tires are described and compared with results of evaluations of 21 foreign and domestic vehicles. The significance to vehicle handling of tires having different characteristics, as determined by subjective evaluations in a lane change maneuver, is shown.

This paper describes several alternative approaches, provided by multiplane-multispeed balancing, to traditional gas turbine engine manufacture and assembly procedures. These alternatives, which range from addition of trim-balancing at the end of the traditional assembly process to modular design of the rotating system for assembly and balancing external to the engine, require attention by the engine designer as an integral part of the design process. Since multiplane-multispeed balancing may be incorporated at one or more of several points during manufacture-assembly, its deliberate use is expected to provide significant cost and performance (reduced vibration) benefits. Moreover, its availability provides the designer with a firm base from which he may advance, with reasonable assurance of success, into the flexible rotor dynamic regime.

This paper examines some present day problems which are of particular interest with respect to driving safety when we regard the development of the chassis for compact automobiles. These problems include suspension suitability for radial tires, axle kinematics, vibration characteristics, brake system design, handling, and legal requirements. /GMRL/

This paper presents the various features and operational properties of a two-dimensional mathematical model of crash victim motions. The features of this model include: (1) An eight mass representation of the human body where contact between the crash victim and the vehicle is represented in terms of independent force-deformation properties of the victim and the vehicle. (2) An extensible multijoint neck and a realistically flexible shoulder joint. (3) A real- line representation of the vehicle interior or exterior where shape is given as a network of points. (4) Specific predictive restraint device submodels for the airbag, the energy absorbing steering column, and a slipping, energy absorbing three-point-belt restraint system. (5) A flexible output package including graphics, an injury criteria monitor, and a variety of options for listing, deleting, and comparing selected output variables.

This paper explains the Ford solid state ignition system and the objectives and design philosophy that was used in the development of the system. Further, a review of the design and production validation test plans is discussed. With this background, specific examples of the effectiveness of complete problem analysis for fundamental cause and corrective action is presented in addition to control methods and evaluation of corrective action.

Rear disc brakes were released as standard equipment on 1975 Mark IV and as a regular production option on 1975 Lincoln, Thunderbird, and Mercury. This brake is the result of a joint Ford/Kelsey-Hayes design and development effort. The key feature is a single-piston sliding caliper with an integral, self-adjusting parking brake mechanism. The design offers great flexibility in packaging on various car lines and on different axles. This paper describes the major features of the design and the significant problems found and overcome in the development program. /SAE/

The paper describes the approach taken in the design and fabrication of a 4-cyl in-line trunk piston steam expander suitable for a standard six-passenger automobile. Series poppet admission valving is used with variable cutoff of steam to the expander attained by variable phasing of one camshaft with the aid of a hydraulically operated cam phasing mechanism. A specially formulated lubricant is used which allows expander operation with steam at 1000 degrees F/1000 psig. Preliminary performance measurements for the expander are presented and results are thought to be good considering the maturity of the system. Improvements to the expander which will result in increased efficiency are discussed.

This paper discusses a facility to assist the designer in development of test instrumentation. Emphasis is placed on use of the microcomputer as an integral part of system design. Test instrument applications are cited. /GMRL/

This paper describes the conversion of a crash analysis program from its original batch program form with awkward input to an efficient, user-oriented interactive tool. The program simulates a vehicle occupant with a two dimensional, seven link mathematical model restrained by a seat belt and shoulder harness. A nonlinear finite element capability was added to enable modeling of a seat which would interact realistically with the occupant. A new differential equation solver was developed which achieved a sixty percent reduction in the computer time required for the transient response analysis.

The paper discusses the fundamental origins of truck noise and shows the rate at which the noise of each individual source increases with speed. Various means of controlling noise from each component are considered. A method of predicting engine noise, and hence vehicle noise, from basic engine speed and piston diameter data is given and the significance of this information to the engine designer is emphasized.

This paper, originally published in 1972, describes experiments of air bag systems conducted considering the out-of-position child. Baboons of approximately the same weight as a child were used to provide the most realistic evaluation of potential injuries. The experiments were conducted with a prototype right front passenger air bag system. Five distinct positions were chosen to represent the out-of-position child. Findings indicated that the deploying air bag in the system studied had sufficient force to propel 29-34 lb baboon over the front seat back. With the present configuration of the air bag as studied, there is danger of head and internal organ injuries to a child during static inflation.

This paper discusses a program wherein studies were made of forward force simulations of crashes and destructive barrier crashes using a shaped steering assembly airbag. It was shown that the airbag was offered the best protection when compared with the performance of lap belts and lap and shoulder belt combinations. This shaped airbag deploys between the abdomen and the steering wheel and between the head and the steering wheel, thus providing protection of these two important areas.

An investigation to determine why the hydrocarbon content of automobile exhaust gas increases abruptly during deceleration and how this can be prevented is described in this paper. High-speed motion pictures of the flame, taken through a quartz-window cylinder head, show incomplete combustion under these conditions. Additional experiments established that excess residual-gas dilution is the major cause of the incomplete combustion. The concentration of hydrocarbons in the exhaust can be reduced either by admitting extra air and fuel to the intake manifold to limit vacuum attained during deceleration or by shutting off the fuel during deceleration.

Turbojet engine reliability has long been an intense interest to the military users of this type of aircraft propulsion. With the recent inauguration of commercial jet transport this subject has assumed a new dimension of importance. In January l96 the Lewis Research Center of the NASA (then the MACA) published the results of an extensive study on the factors that affect the opera- center dot tional reliability of turbojet engines (ref. 1). At that time the report was classified Confidential. In July l98 this report was declassified. It is thus appropriate at this time to present some of the highlights of the studies described in the NASA report. In no way is it intended to outline the complete contents of the report; rather it is hoped to direct attention to it among those who are center dot directly concerned with this problem. Since the publication of our study over three years ago, the NASA has completed a number of additional investigations that bear significantly on this center dot subject. A second object of this paper, therefore, is to summarize the results of these recent studies and to interpret their significance in relation to turbojet operational reliability.

This paper reviews the development of the Sikorsky Stowed Rotor concept for high speed V/STOL aircraft from its conception in 1949 to the present. The philosophy behind this concept is discussed along with its significant advantages and major problem areas. New design approaches and application studies of the Stowed Rotor against current high speed V/STOL missions are described. Results of recent flight simulator studies and wind tunnel tests are presented which confirm the feasibility of this concept.

Because the use of seat belts when available is mandatory in Australia and now at a high level, a high proportion of those who crash are wearing seat belts. The further protection of these occupants is high priority. This paper reports a study of a series of fatally injured occupants of recent-model passenger cars, performed in order to investigate the potential for extension of the limits of seat belt performance in crashes that are currently fatal. Improvements in seat belt design and installation should reduce a proportion of current losses from death and injury, but further reductions in these losses will demand attention not only to the crashworthiness of the car but also to the characteristics of the other vehicles and roadside structures that are commonly impacted.

The purpose of this paper is to describe an investigation of separate surface stability augmentation systems for general aviation aircraft. The program objective were twofold: first, a wind tunnel program to determine control effectiveness of separate surfaces in the presence of main surfaces, and hinge moment feedback from separate surfaces via the main surfaces to the pilot; second, a theoretical study to determine the minimum performance of actuators and sensors that can be tolerated, the best slaving gains to be used with separate surfaces, and control authority needed for proper operation under direct pilot control, under autopilot control, and in failure situations. On the basis of the results obtained, it has been concluded that separate surface systems are feasible and advantageous for use in general aviation aircraft.

This paper studies the effects of wearing seat belts in severe crash impacts in Victoria, Australia. In the study it was found that there were some injuries associated with wearing seat belts, but most of these were minor. There was an association between incorrect adjustment of seat belts and the occurrence of injury. There is a need for seat belt systems to be foolproof so that they can only be worn correctly.

Diesel engine noise can be reduced by modifying the combustion pressure-time history and the engine structure. This paper deals with the correlation between combustion excitation level and noise, and the effects of speed, timing, load, compression ratio, and combustion system configuration on combustion excitation. Engine structural modifications including increased stiffness, isolation, and damping are considered. The effects on noise and vibration are presented for increased block stiffness and isolation and damping of various engine covers.

Several unique techniques and related devices are described which are in use at the Lewis Research Center for off-design testing of fan and compressor sections in full-scale jet engines. The devices presented permit a wide range of experimental conditions and minimize downtime for hardware changes. The techniques involve use of such devices as inlet pressure distortion jets, a hydrogen burner for inlet temperature distortions, fan back pressure jets to simulate a variable area nozzle, and either an inflow-outflow bleed system or a fuel spurt system to alter compressor discharge pressure.

The primary function of a motor vehicle brake fluid is to provide a means for transmitting pressure from the brake pedal to the wheel cylinder or caliper where the pressure is transformed into the required braking effort. In order to perform this function efficiently, the brake fluid must remain in a liquid state free of gas or air bubbles so that compressibility is not a significant factor. The performance of brake fluid in braking systems in service is a matter of primary interest to brake engineers. The effect of water contamination on conventional glycol ether type brake fluids is discussed and compared with the capabilities of water intolerant fluids in conventional braking systems.