Random Load Simulation in Laboratory Fatigue Testing PDF Download

Author: Society of Automotive Engineers, Inc
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 11

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Book Description

Author: Ravishankar, T. J
Publisher: Institute for Aerospace Studies, University of Toronto
ISBN:
Category : Airframes
Languages : en
Pages : 39

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Book Description
The methods used in laboratory simulation of random service load conditions, that lead in practice to fatigue failure e.g. aircraft structures, are reviewed. First, the inter-relation of the atmospheric turbulence with the resulting loads on the aircraft are discussed. Then follows an analysis and interpretation of service load histories and a review and comparison of the methods in use for simulating service load spectra of arbitrary and random load sequences. Both random loading, using discrete load levels or analogous random process testing, are discussed. Full scale testing is also reviewed. In appendices, stationary random processes and fewer spectral density functions an evaluation of probability distributions of RMS gust velocities and some damage theories are presented. (Author).

Author: P. R. Abelkis
Publisher: ASTM International
ISBN:
Category :
Languages : en
Pages : 291

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Book Description

Author: J. D. Camp
Publisher:
ISBN:
Category : Automobiles
Languages : en
Pages : 13

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Book Description
A general method is described for the application of random vibration techniques to a laboratory road simulation of a road durability schedule as used by Pontiac Motor Div., General Motors Corp. Basic philosophy as well as specific recommendations are given for the design of the procedures in evaluating the parameters influencing the road simulation. Instrumentation and data reduction techniques are discussed with application to a new concept in laboratory road simulation. A three-axis input, hydraulic shaker road simulator is described which duplicates the random road profile in the fatigue testing of a complete vehicle. A road-simulated endurance test can be programmed which can utilize either magnetic tape or programmed random noise command to electrohydraulic shakers. The test program includes recording of the random road inputs to the vehicle suspension, analysis of these inputs by power spectral density and statistical techniques, and duplication of these random inputs with the shaker facility for vehicle structure fatigue test, with analysis of data from the shaker facility to insure that the force inputs from the road simulator are actually as the car sees the inputs as it is being driven on the road.

Author: C. Amzallag
Publisher: ASTM International
ISBN: 0803119852
Category : Fracture mechanics
Languages : en
Pages : 668

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Book Description

Author: Eugene C. Naumann
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 36

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Book Description
An investigation has been conducted to determine which combination of method counting and type of load programing best retains the essential fatigue-inducing characteristics of a random time history of stress. In an earlier investigation several time histories were numerically generated and counted by various methods. The data obtained in the earlier investigation were used in this investigation to conduct axial load fatigue tests of 2024-T3 aluminum-alloy sheet specimens with not d edges. The fatigue life obtained from tests using the random peak history was used as a basis of comparison. The elimination of various sized fluctuations, due to the different counting methods, had little, if any, effect on fatigue life in tests using a random sequence of loads. Tests conducted by using ordered loading produced lives greater than the random fatigue life. The value of life in the ordered tests varied with the counting method, with statistical properties of the time history, and probably with the assumptions made in reducing the data to block form.

Author: John M. Potter
Publisher: ASTM International
ISBN: 0803111851
Category : Aluminum alloys
Languages : en
Pages : 242

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Book Description

Author: Walter Schutz
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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Book Description
The report briefly discusses the papers given at the conference. The titles of the papers are: A short survey on possibilities of fatigue life assessment of aircraft structures based on random or programmed fatigue tests; Some effects of change in spectrum severity and spectrum shape on fatigue behaviour under random loading; The accumulation of fatigue damage in aircraft materials and structures; Effects of test frequency on fatigue crack propagation under flight-simulation loading; Correlation between laboratory tests and service experience; On residual stresses during random load fatigue; The fatigue life under three different load spectra - tests and calculations; A relation between measured C.G. vertical accelerations and loads at the T-tail of a military airplane.

Author: W. Weibull
Publisher: Elsevier
ISBN: 1483154165
Category : Technology & Engineering
Languages : en
Pages : 322

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Book Description
Fatigue Testing and Analysis of Results discusses fundamental concepts of fatigue testing and results analysis. The book begins with a description of the symbols and nomenclature selected for the present book, mainly those proposed by the ASTM Committee E-9 on Fatigue. Fatigue testing methods are then discussed including routine tests, short-life and long-life tests, cumulative-damage tests, and abbreviated and accelerated tests. Separate chapters cover fatigue testing machines and equipment; instruments and measuring devices; and test pieces used in fatigue testing. The factors affecting test results are considered, including material, types of stressing, test machine, environment, and testing technique. The final two chapters cover the planning of test programs and the presentation of results. Test program planning involves the statistical design of a test series; specification and sampling of test pieces; and choice of test pieces, testing machines, and test conditions. The chief purpose of most fatigue tests is the experimental determination of the relation between the endurance and the magnitude of the applied stress range for the material and the specimen under consideration, and final results can be condensed into a table, graph, or analytical expression.

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 652

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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.