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Viewing 7621 to 7650 of 7819
1963-01-01
Technical Paper
630585
R. Boteilho
1962-01-01
Technical Paper
620218
R. W. Plume, W. C. Mclntyre
A laboratory system to evaluate shake characteristics in as many as six cars a day has been developed at the GM laboratories. The total vehicle is subjected to front and rear excitation frequencies ranging from 400–1200 cpm, and even as high as 2400 cpm. The data for each mode of vibration during a frequency scan of approximately three minutes are stored in a multichannel tape recorder which also provides automatic playback and plotting of results. This laboratory method has demonstrated good correlation with subjective road evaluations.
1962-01-01
Technical Paper
620324
J. C. Snowdon
Discussed in detail is the manner in which the damping possessed by rubber-like materials and structures experiencing sinusoidal vibration may be represented by the ratio of the imaginary to the real part of a complex elastic modulus. Examples are given of the way in which the damping possessed by low- and high-damping rubbers depends on frequency. Equations that predict the response to vibration of such distributed systems as damped rods and beams, and a simple structure comprised of two damped beams and a lumped element of mass are derived; and representative computations of input impedance and transmissibility are presented.
1962-01-01
Technical Paper
620464
John E. Steiner, George R. Dvorak
Studies in a jet passenger airliner to service shorter routes than those of the Boeing 707 evolved the concept of a rear mounted three engine jet, the 727. The development program had many facets, including extensive use of mockups, customer influence on design through liaison, cost control, and a considerable amount of work on the design of the tail and location and number of engines on the craft.
1962-01-01
Technical Paper
620532
J. M. Tyler, T. G. Sofrin
1962-01-01
Technical Paper
620491
Rainey A. Gerald, Harry L. Runyan
SUMMARY The various sources of loads of importance in the design of launch vehicles are discussed generally. The natural vibration modes, which are an essential ingredient in all loads problems, are described for the Saturn vehicle as obtained from a structural replica model. The effects of fuel loading on the structural modes are considered and the results obtained on the model are compared with full-scale results. Launch-vehicle buffeting is discussed and the buffeting characteristics of a manned lunar vehicle configuration are described. Some evaluations of buffeting scaling laws obtained with this configuration are presented. Estimates of the acoustic environment on the spacecraft associated with engine noise at lift-off and with aerodynamic noise due to buffeting are shown. The steady and vibratory loads due to ground winds as determined from wind-tunnel tests of a Saturn model are presented.
1962-01-01
Technical Paper
620505
Henry W. Schab
To achieve satisfactory noise reduction of machinery used for military and industrial use, the problem ideally should be attacked at the source of noise production. However, in many cases it may not be possible to reduce effectively the source noise because of design and (or) economic considerations, and techniques such as transmission path control must be utilized. This paper identifies noise source characteristics of mechanical and electrical equipment such as gas turbines, diesel engine, generators, motors, and their components. Reduction of vibration through balancing techniques is emphasized.
1962-01-01
Technical Paper
620131
Arturo Chiesa
In the first part of this paper methods recently developed for the study of the oscillations of running vehicles are described as well as two types of analysis. Some information about the apparatus used for recording and analysis are given. In the second part the results of the analysis of the vertical vibration of a car fitted with three types of tires running on various types of road at various speeds are presented and discussed. Finally, in the third part, the possible influences of tires on the vertical vibration of the vehicle are surveyed. The viscoelastic deformations of the tires cause middle frequency oscillations which are transmitted from the tires to the unsprung masses and to the car body.
1962-01-01
Technical Paper
620080
Elmer K. Green
1962-01-01
Technical Paper
620090
D. W. McDaniel
1961-01-01
Technical Paper
610109
Allan G. Piersol
1961-01-01
Technical Paper
610107
P. W. Smith
1961-01-01
Technical Paper
610173
IR. H. C. A. van ELDIK THIEME
SUMMARY Because the ride comfort problem is a very complex problem, as a general feeling of well-being in a vehicle, only one aspect will be discussed in the paper, namely that of the mechanical vibrations in a frequency region of 0.1 - 100 cps. The objective method of physiological and performance tests will be briefly related, but more attention will be paid to the subjective research methods, where a person gives his own sensation opinion. On the basis of the studies of human tolerance to vibrations, a number of comfort criteria is discussed. With the aid of these criteria results have been achieved in the examination of acceleration records and tapes with modern high-speed level analysers and computing equipment.
1961-01-01
Technical Paper
610028
F.B. Greatrex
1961-01-01
Technical Paper
610022
James W. Mohr
1961-01-01
Technical Paper
610008
R.H. Bollinger, J.H. Ruhl
1961-01-01
Technical Paper
610577
Rene Bouquet
1961-01-01
Technical Paper
610554
S. Rubin
1961-01-01
Technical Paper
610555
Roy W. Mustain
1961-01-01
Technical Paper
610559
Edward L. Richardson
1961-01-01
Technical Paper
610553
F. B. Safford
1961-01-01
Technical Paper
610552
W. W. Harter
1961-01-01
Technical Paper
610541
J. W. LISKA, J. SIDLES
1961-01-01
Technical Paper
610545
L. M. MORRISH, R. R. HAIST
1961-01-01
Technical Paper
610522
D. L. BERNHARD
1961-01-01
Technical Paper
610419
R. L. Bennett
1960-01-01
Technical Paper
600037
Sheldon Rubin
PAPER DESCRIBES a procedure for the dynamical design of linear vibration isolators to protect a rigid equipment from the sinusoidal motions of a nonrigid supporting structure. A single degree of translational freedom of the equipment is assumed. Three types of data are required: (1) The equipment mass and its so-called fragility curve, (2) the mechanical admittance of the supporting structure and its amplitude of vibration when it supports no load, and (3) information to establish a minimum stiffness of the isolators. The procedure yields a region of permissible natural frequency and fraction of critical damping combinations for the isolator-mass system. The specification for the isolator dynamical requirements, including allowable tolerances, is derived from this region.*
1960-01-01
Technical Paper
600015
E. S. Starkman, W. E. Sytz
SIMULTANEOUS RECORDINGS of cylinder pressure, audible sound, and crankshaft motion have shown that rumble is a noise associated with bending vibrations of the crankshaft. The vibrations are caused by abnormally high rates of pressure rise near the top dead center piston position. In this study the high rates of pressure rise were obtained by inducting deposits into the the engine. Thud is a torsional vibration of the crankshaft, similar in sound to rumble but resulting from much earlier occurrence of the maximum rates of pressure rise. Rumble vibrations consisted of a fundamental frequency of 600 cps and higher harmonics in the 11/1 compression ratio V-8 laboratory engine used in the investigation. The audible noise of rumble was predominantly composed of the second harmonic or about 1200 cps.
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