Author: John M. PotterPublisher: ASTM International
ISBN: 0803111851
Category : Aluminum alloys
Languages : en
Pages : 242
Book Description
Development of Fatigue Loading Spectra
Author: John M. PotterPublisher: ASTM International
ISBN: 0803111851
Category : Aluminum alloys
Languages : en
Pages : 242
Book Description
Fatigue Spectra Development for Airborne Stores
Author: HO. FuchsPublisher:
ISBN:
Category : Airborne stores
Languages : en
Pages : 15
Book Description
Traditionally, airborne store design has been based on service life criteria similar to those used for aircraft development. Recent research has shown that an airborne store may be exposed to a unique loading environment and may therefore require a different approach. Moreover, flight loads data for aircraft and airborne stores are normally difficult and expensive to obtain, because resources are not available to fly a sufficient variety of combinations of aircraft, stores, and mission types. Finally, the increased life of many stores has made fatigue life an important consideration in design. These considerations led to development of an approach to building flight-load spectra for fatigue testing of externally mounted airborne stores (that is, fuel tanks, missiles, bombs, etc.) using time-history load data collected from U.S. Air Force and Navy training flights. The data are processed using a "racetrack" type data compaction algorithm to yield sequential peak/valley pair files, and then reorganized to build new mission profiles. Finally, the new mission profiles are weighted by expected frequency of occurrence and organized to reflect the expected service use over a period of time.
Development of Fatigue Loading Spectra for Testing Aircraft Components and Structures
Author: A. J. McCullochPublisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 28
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.
Landing Gear Fatigue Spectrum Development for Part 25 Aircraft
Author: Service Fatigue Loads Monitoring, Simulation, and Analysis
Author: P. R. AbelkisPublisher: ASTM International
ISBN:
Category :
Languages : en
Pages : 291
Book Description
Development of Flight-by-Flight Fatigue Test Data from Statistical Distributions of Aircraft Stress Data
Author: Michael C. HillPublisher:
ISBN:
Category : Aerodynamic load
Languages : en
Pages : 403
Book Description
This report documents the computer programs and subroutines written in support of the effort presented in Volume I. The report describes and documents two aircraft simulation programs used to process flight loads data derived from B-58 and F-106 aircraft flying operational missions. A simulation merge program is also included which combines the output tapes from the aircraft simulation programs and generates an output tape compatible with the hybrid computer. The program listings and sample problems for the simulation programs are presented in the Appendices.
The Effects of Truncation and Marker Loads on Spectrum Fatigue Crack Growth
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
The US Air Force is operating a large fleet of aging aircraft. Some examples of problems that aging aircraft can encounter are fatigue and corrosion. Throughout the Air Force and industry, many research efforts are being conducted to deal with the aging aircraft problems. Many of these efforts require a significant amount of fatigue testing, both constant amplitude testing, which can be relatively fast, and spectrum fatigue testing, which can take a significant amount of testing and inspection time. One of the main objectives of this research effort was to determine whether spectrum truncation has a noticeable effect on crack growth rates. In order to save valuable testing time, the duration of spectrum fatigue tests can be shortened by truncating the spectrum. When truncating a spectrum, small fatigue cycles that are not expected to contribute to the overall crack growth life of the specimen or structure, can be removed from the spectrum. By doing so, a significant amount of test time can be saved. It is very important though that by excluding these small fatigue cycles from the spectrum, the overall crack growth behavior will not change. Another important objective of this effort was to verify that the insertion of marker loads into a fatigue spectrum has no or a negligible effect on the crack growth rate when compared to a fatigue test without the marker loads. When running a fatigue test to determine crack growth rates, regular inspection is necessary to check the crack size versus cycle count, which can be very time consuming and might prevent running tests overnight. When inserting marker loads in a fatigue test, the test can be.
Aeronautical Engineering
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 568
Book Description
A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Development of Fatigue Spectra
Author: John M. PotterPublisher:
ISBN:
Category : Materials
Languages : en
Pages : 238
Book Description
Development of Flight-by-Flight Fatigue Test Data from Statistical Distributions of Aircraft Stress Data. Volume II. Documentation of the B-58 and F-106 Fatigue Spectra Simulation Programs
Author: Michael C. HillPublisher:
ISBN:
Category :
Languages : en
Pages : 405
Book Description
This report documents the computer programs and subroutines written in support of the effort presented in Volume I. The report describes and documents two aircraft simulation programs used to process flight loads data derived from B-58 and F-106 aircraft flying operational missions. A simulation merge program is also included which combines the output tapes from the aircraft simulation programs and generates an output tape compatible with the hybrid computer. The program listings and sample problems for the simulation programs are presented in the Appendices.