Development of Fatigue Loading Spectra PDF Download

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

View

Book Description

Author: Pedro H. Alves Corrêa
Publisher: Editora Dialética
ISBN: 6525253217
Category : Technology & Engineering
Languages : en
Pages : 68

View

Book Description
This thesis consists of a fatigue study carried out on an aluminum alloy 2024-T3 in both time domain and frequency domain. Non-zero mean random signals of strain and stress are analyzed in time domain using usual Rainflow method and the damage is accumulated with the Palmgren-Miner rule, according to mean stress equations. The signals are analyzed in frequency domain using the power spectral density and the probability density function. The spectral domain analysis does not consider the negative effect of the mean stress in metal life under fatigue, so the correction factors for mean stresses developed by Goodman, Morrow, and Smith-Watson-Topper are used to change the power spectral density and, thus, the damage calculated by the probability density functions postulated by Dirlik and Tovo and Benasciutti. It is found that both Dirlik and Tovo and Benasciutti are non-conservative for a non-zero mean stress signal when comparing the damage to the one obtained in time domain analysis. When the spectral method is corrected, the results vary from Rainflow 4.9% for wide band and 6.8% for narrow band signals, always in the conservative zone, therefore predicting more damage. Tovo and Benasciutti 2 method is found to be the spectral function with the closest results when compared to the usual Rainflow method in time domain.

Author: John M. Potter
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 238

View

Book Description

Author:
Publisher: ASTM International
ISBN:
Category : Alloys
Languages : en
Pages : 362

View

Book Description

Author: John M. Potter
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description

Author: Jaap Schijve
Publisher: Springer Science & Business Media
ISBN: 0792370139
Category : Science
Languages : en
Pages : 528

View

Book Description
This is primarily a textbook written for engineers, students and teachers, and for people working on fatigue problems of engineering structures and materials. An important theme is what happens in the material of an engineering structure subjected to a spectrum of cyclic loads in service

Author: D. F. Bryan
Publisher: ASTM International
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 246

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description

Author: A. J. McCulloch
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 28

View

Book Description
The development of frequency-of-occurrence distributions or spectra of loadings for an aircraft structure requires the use of all available information on the aircraft's service and on the loadings peculiar to this service. Interest in these loadings is not new, but there is a growing appreciation of the need for detailed information on the load and stress histories that they produce. The need for such information has led to the collection of quantities of service loading data covering a wide range of operational conditions. However, use of the data has generally been restricted to assessments of the adequacy of design load levels and to analytical evaluations of the effects of service loadings on the life of the structure. The direct use of the data in test evaluations of structures is a fairly recent and rather controversial development. The need for this development will be brought out in a brief review of fatigue testing. This review will be followed by a brief discussion of the operational conditions to be considered in the construction of loading spectra. Selection of the most appropriate operational conditions is the first and a very important step in any fatigue evaluation. Inadequate selections can have a major effect on the interpretation of fatigue test results. The generally available data on particular classes of service loadings will then be described in some detail. This description will attempt, by supplying background data, to throw some light on the bases for generalized representations of service loading histories and so provide an indication of their utility. Finally, the use of defined operational conditions and of standardized loading spectra in the construction of test spectra to represent particular aircraft utilizations will be described and illustrated.

Author: J. E. Holpp
Publisher:
ISBN: 9789283512028
Category : Airframes
Languages : en
Pages : 31

View

Book Description
A realistic loading spectrum is a necessity in order to predict the fatigue or crack growth life of a component. Realistic loading spectra encompass many disciplines, including loads, stress, fatigue and crack growth analysis, and the realism of the spectrum will be dependent on the accuracy of the input data and the degree of complexity that the analyst is able or willing to undertake. External factors such as time and money considerations, available data, degree of accuracy required, etc., also affect the process of spectrum development and these factors often force the use of simpler, less time consuming, less expensive techniques than those desired to produce adequately realistic results. Steps in developing a loading spectrum which are covered in this report include: mission profile definition; loading environment; loading conditions; structural loads analysis; stress analysis; and stress sequencing. The simpler techniques available are discussed whenever appropriate. A detailed example of a spectrum development on a fighter/strike aircraft is included.