Premium
Crack growth in the gigacycle fatigue regime for helicopter gears
Author(s) -
Shaniavski,
Skvortsov
Publication year - 1999
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1046/j.1460-2695.1999.00188.x
Subject(s) - durability , fatigue testing , structural engineering , paris' law , stress (linguistics) , materials science , stress concentration , engineering , forensic engineering , crack closure , fracture mechanics , composite material , linguistics , philosophy
Investigations were performed on helicopters’ gears that had failed in service, using quantitative fractographic analyses. It was shown that a combination of LCF and HCF creates damage in gears on a flight‐by‐flight basis which produces beach marks on the fatigue surface of the gears that correlate one‐to‐one with flight cycles. The crack increment between beach marks occurs under HCF at 7000–8000 r.p.m. The ratio of the crack growth period to durability is smaller in the gigacycle fatigue area (more than 10 8 cycles) than in the high cycle fatigue area (10 6 –10 7 cycles) for those gears investigated that have stress raisers. This relationship for damaged gears depends not only on durability but also on the type of stress raiser and its location.