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Probabilistic Analysis of Aircraft Gas Turbine Disk Life and ReliabilityTwo series of low cycle fatigue (LCF) test data for two groups of different aircraft gas turbine engine compressor disk geometries were reanalyzed and compared using Weibull statistics. Both groups of disks were manufactured from titanium (Ti-6Al-4V) alloy. A NASA Glenn Research Center developed probabilistic computer code Probable Cause was used to predict disk life and reliability. A material-life factor A was determined for titanium (Ti-6Al-4V) alloy based upon fatigue disk data and successfully applied to predict the life of the disks as a function of speed. A comparison was made with the currently used life prediction method based upon crack growth rate. Applying an endurance limit to the computer code did not significantly affect the predicted lives under engine operating conditions. Failure location prediction correlates with those experimentally observed in the LCF tests. A reasonable correlation was obtained between the predicted disk lives using the Probable Cause code and a modified crack growth method for life prediction. Both methods slightly overpredict life for one disk group and significantly under predict it for the other.
Document ID
Document Type
Technical Memorandum (TM)
Melis, Matthew E.
(NASA Glenn Research Center Cleveland, OH United States)
Zaretsky, Erwin V.
(NASA Glenn Research Center Cleveland, OH United States)
August, Richard
(NYMA, Inc. Brook Park, OH United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1999
Subject Category
Mechanical Engineering
Report/Patent Number
NAS 1.15:107436
Funding Number(s)
PROJECT: RTOP 523-22-13
Distribution Limits
Work of the US Gov. Public Use Permitted.
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