Refine Your Search

Topic

Author

Affiliation

Search Results

Standard

Brake Rotor Thickness Variation and Lateral Run-Out Measurements

2015-10-02
WIP
J3111
The scope of this recommended practice is to establish definitions and recommended methods for the measurement of lateral run-out and disc thickness variation in the laboratory and vehicle for passenger cars and light duty trucks up to 4546 kg gross vehicle weight. This recommended practice will breakdown the instrumentation (sensors and sizes), test setup, and data processing.
Standard

Component Level EPB Actuation NVH

2018-01-10
WIP
J3165
The component level EPB actuation NVH task force should review existing specifications and measurement methods used in the industry to find any commonalities and propose a recommended method for measuring and evaluating component level EPB actuation NVH to be used as a common standard throughout the industry. The task force should acknowledge the following objectives: 1. Task force should review existing industry specifications and further define the scope for creating the new standalone component level EPB actuation NVH standard a. The common standard should be universally recognized and accepted by the automotive industry b. Provide confidence that acceptable vehicle related NVH results will be achieved if vehicle level testing is completed c. Provide clear verifiable acceptance criteria 2. Task force must lay out steps and timing to complete the development of the new common standard. 3.
Collection

Powertrain NVH, 2017

2017-03-28
The papers in this collection reflect the recent advances on the research, development and practices of Powertrain NVH treatment. The technical papers are of interest to powertrain system designers, testing specialists, NVH experts, and other individuals who evaluate and develop technologies to control powertrain NVH. The coverage includes: engine, engine subsystem and components noise and vibration; powertrain systems noise measurement and instrumentation; powertrain systems noise analysis.
Video

Spotlight on Design Insight: Sensors: Noise Avoidance and Cable Manufacturing

2015-05-07
“Spotlight on Design: Insight” features an in-depth look at the latest technology breakthroughs impacting mobility. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. Extreme environment sensors require extreme environment cables that can reliably perform in temperatures up to 2300° F, withstand intense vibration, and have extraordinary strength. In the episode “Sensors: Noise Avoidance and Cable Manufacturing” (8:53), an engineer at Meggitt Sensing Systems demonstrates the intricate process of developing cable for sensors used in these situations.
Technical Paper

Vibration in Automobile Engines

1928-01-01
280048
In this article the author presents analytical methods for determining the unbalanced inertia force and the tangential effort in a line engine. These methods are thought to be of interest for investigation of the effects of various engine design-features on its vibration characteristics. An equation for the resultant reciprocating force is set forth and methods of expressing the inertia and fluid-pressure torque are given. The determination of minimum and maximum resultants and the balance of inertia and fluid-pressure torques are other topics dealt with. The results of a series of analyses are incorporated in tabular form.
Technical Paper

The Angular Distortion of Crankshafts

1928-01-01
280049
REFERENCES are given to many articles and books on crankshaft vibration, written in both English and German. As published experimental data on deflections are lacking, the authors obtained an engine with four crankshafts, having crank-arms with different cross-sections, and measured the deflections under static load. Deflections in various parts of the shafts are analyzed and compared, and a formula is developed for the deflection in the long crank-arms of the shaft.
Technical Paper

Correlation of Propeller and Engine Power with Supercharging

1933-01-01
330005
THE primary purpose of this paper is to discuss some of the most pressing problems involved in choosing the propeller that is most suitable for use on a particular airplane. Propeller design is not dealt with, the discussion being limited to the selection of metal propellers of established design. Questions of noise, efficiency and diameter limitation are merely mentioned, and the emphasis is placed upon the choosing of propellers which will transmit the most engine power for the most needed condition of airplane performance; maximum and cruising speeds at altitude, or take-off and climb. Airplane performance enters only inasmuch as it is used to illustrate a case of power absorption. The proper choice of a propeller is becoming increasingly difficult to determine because of the current design trends of both airplanes and engines. Especially important is the fact that many of the supercharged engines now in use cannot be operated at full throttle below their critical altitudes.
Technical Paper

The WHY and HOW of THE RUBBER-TIRED RAILROAD-COACH

1933-01-01
330001
Railroads are facing a crisis in operating costs, the urge toward reduction of unnecessary weight has become widespread and the crusade for noise abatement is no longer to be denied, according to the author. The pneumatic-tired railroad-coach not only answers these requirements, he says, but anticipates a demand for a new traveling comfort. The desire to rubberize railroad equipment is old but much fruitless research has resulted from directing it chiefly toward solid-rubber or cushion tires. Road and rail surfaces present entirely different problems so far as the tire is concerned. No uniformity of conditions obtains on highways but rails are even and smooth. A badly aligned joint such as would wreck a metal wheel makes no impression on a pneumatic tire. As simple as the tire problem may seem, its solution represents years of courageous and skillful research on the part of the Michelin company in France.
Technical Paper

An Analysis of Tires and Wheels as Causes of “Tramp”

1933-01-01
330042
THIS paper presents the solution of the factors in tires and wheels that cause a particular type of front-end vibration termed “tramp,” which is a vertical vibration of the front axle accompanied by a small degree of simultaneous oscillation of the wheel assembly about the king pin. This vibration in turn sets up the disturbance of the body and chassis. The front-axle vibration is caused by the unbalance and variation in rolling radius of the rotating front-wheel assemblies. The theoretical action of these two factors is developed in detail and supported by experimental results. The foregoing two factors act independently. The resultant of the two periodic forces which they set up depends on their phase relationship.
Technical Paper

Airplane Vibrations and Flutter Controllable by Design

1933-01-01
330030
THE purpose of this paper is to pass on to airplane designers the things that have been learned in the last year about flutter and vibration of structures to which control surfaces are attached in order that, benefiting by all experience available, this great source of danger in new designs may be controlled. Test pilots also should be interested in this subject because it may help them in deciding proper action when a case of flutter is encountered and to recognize vibrations which may lead to destructive flutter. The present-day methods of stress analyses, imperfect though they are in certain respects, and the design load-factors in current use are adequate to provide all the strength needed in airplane structures for flight in rough air, and for all necessary maneuvers. A review of structural failures in the air reveals the fact that a resonant vibration was in nearly all cases responsible.
Technical Paper

HOW VERSATILE ENGINEERING MEETS PUBLIC DEMAND

1933-01-01
330032
Irritated by statements of some alleged economists to the effect that, except for changes in the appearance of motor-cars, the automobile industry has stood still for the last five years, the author of this paper, who is affectionately regarded as the dean of automobile engineering in this Country, spoke at meetings of the Philadelphia and Metropolitan Sections of the Society on the many car and engine improvements made in recent years. Mr. Crane's remarks, as reported stenographically and embodied in this paper, deal chiefly with engines. He points out that extensive highway improvement and the consequent public demand for higher car speed have forced engineers to design more powerful and more versatile engines without increasing the weight. High-speed engines were of necessity the answer, and these brought the problem of eliminating roughness of operation and preventing transmission of vibration to the chassis.
Technical Paper

Automobile Engineering Progress

1932-01-01
320023
GENERAL DESIGN and detail mechanical developments that have been made in the last year and incorporated in automobile, truck and motorcoach models for 1932 are reviewed by the author, who also points out noticeable trends in a number of directions. He deals in order with the cars as a whole and with each major component, from the powerplant to the tires and body, as found in many leading makes. Decision of the industry not to announce the details of new models until the end of the year, at or immediately before the opening of the New York Automobile Show in January, interfered with the presentation at this time of a complete picture of all the improvements made in American motor-vehicles, but enough information is believed to be given to show the more important developments and the ways in which the automotive engineers have responded to the desire of the times for greater refinement and efficiency in automobiles.
Technical Paper

Vibration of Instrument-Boards and Airplane Structures

1932-01-01
320010
THIS paper supplements one on the same subject by the same author, published in October, 1931, and describes a new and improved three-component vibrograph with which separate vibrograms of the three components can be obtained simultaneously and with considerable magnification. A short mathematical analysis is given to show the fundamental difference between vibrographs and accelerometers. Effects of vibration on different instruments are discussed and the approximate maximum permissible amplitude of vibration at cruising-speed frequency for various instruments is presented in a table. Consideration is given to correct design of instrument-boards and their suspension in an airplane, and the theory of forced vibration with damping is reviewed to show that, if not rightly chosen, shock-absorbing materials can do as much harm as good.
Technical Paper

Late Developments in Airplane Stress-Analysis Methods and Their Effect on Airplane Structures

1932-01-01
320011
RECENT developments disclose the existence of a well-defined tendency toward greater accuracy and thoroughness in airplane stress-analysis methods, which serve only as a link between applied loads and allowable loads. This trend has just begun. “Although we may justly look with pride on the aeronautical achievements thus far accomplished,” the author says, “our knowledge and ability are far from being complete or entirely satisfactory.” Hence, he analyzes several recurrent stress-analysis problems and indicates methods leading to their solution, because these seem to be outstanding in their ability to cause trouble for airplane designers. Better understanding is needed of the peculiarities of aircraft structure; such as lack of rigidity, the nature of inertia loads, the effects of flutter and of engine vibration, and the dangers of stress concentration.
Technical Paper

Noise and Heat Control in the Automobile Body

1932-01-01
320050
INSULATING of automobile bodies against noise and heat has been made more complicated by the trend toward lower and more compact bodies and larger and more powerful engines, as more noise and heat are created and must be excluded from the body. Development of the all-steel body also has presented a new problem that calls for different treatment than the composite steel and wood body. Elimination of noise and heat from the body is the mutual problem of the chassis and the body engineers and must be attacked jointly, correction of the trouble being made at the most logical and practical places. Much successful work has been done in the last few years to eliminate noise and heat, but much more can be accomplished by further concentrated effort. After listing the more objectionable chassis noises which have received most attention, the author considers the remaining noise and the heat against which the body must be insulated.
Technical Paper

Practical Experiences with Devices for Damping Torsional Vibrations

1931-01-01
310006
EARLY troubles experienced with torsional vibration in the shafting of marine and Diesel engines are mentioned, following which the various types of torsional-vibration damper are listed. Comments on the different ones are presented with particular reference to a damper with hydraulic coupling for a 3000-hp. 10-cylinder Diesel engine. The operation of this damper is described at some length, the text being supplemented by illustrations. Results of tests with this device are presented graphically, and the conclusion is drawn that the damping flywheel with hydrostatic coupling permits (a) damping of vibration of shafting even when running in the most dangerous speed-ranges of the largest engines and (b) running at all speeds without regard to vibration and without resorting to hand operation of the damping device.
Technical Paper

A Study of Airplane and Instrument- Board Vibration

1931-01-01
310036
AIRPLANE vibration produces many undesirable conditions during flight, such as fatigue of structural members, a bad effect on the nervous systems of the occupants and the like. Excessive vibration leads to premature deterioration or to erroneous indications of instruments. Vibrations can be analyzed from a mathematical viewpoint with gratifying results, but such analysis is sometimes difficult and often is applicable only to selected conditions. A serious mathematical analysis was carried out in the investigation of resonance conditions between engine and engine mount. Then the problem was approached from a rather empirical viewpoint to give vibration relations, not, as heretofore, to bodily sensation, but to such terms as amplitude, frequency, the relation between the two, form and the like.
X