ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Using of a safe life approach is necessitated by the small critical crack sizes and rapid crackgrowth rates resulting from the severe vibratory environment of rotorcraft. However Based on thesuccess of damage tolerance initiative for airframe structure, a crack growth based on damagetolerance approach is being examined for implementation into the design and management ofdynamic components. In this paper the crack growth behavior in low cycle fatigue (LCF) and highcycle fatigue (HCF) are compared and the accuracy of several damage tolerance analysis methods indetermining the crack growth life from an initial detectable crack size 1.25 mm to 12 mm for arotorcraft main rotor yoke are investigated. The real rotorcraft materials measured by experiment andthe fatigue load mean frequency spectrum based on statistical usage spectrum are adopted. The crackgrowth equations used in the programs are discussed to provide a basis for understanding the results.The results show that the load less than the safe fatigue limit has an important effect on crackgrowth life and it is reasonable for the material that the cut-off stress ratio for the threshold stressintensity factor range is set 0.7
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.324-325.963.pdf
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