Project engineer, Procter and Gamble, Hamilton, Ontario
Professor, University of Waterloo, Waterloo, Ontario
Pages: 17 Published: Jan 1979
A unified theory for life predictions based upon damage accumulation has been applied to high-temperature, high-frequency, low-cycle fatigue tests of austenitic iron-nickel-chromium alloys (similar to Alloy 800). Damage may be related to the formation of cracks and its accumulation is shown to be a function of the fatigue crack growth rate. Damage accumulation data are reported for small axially loaded smooth specimens for varying strain levels. This in turn may be correlated to an elastic-plastic fracture mechanics analysis through the concept of the J-integral (the J-values being estimated from stress-strain data). It is suggested that relating standard fracture-mechanics concepts to damage accumulation in small specimens will be useful in obtaining a better understanding of the fatigue process.
damage accumulation, high temperature fatigue, fatigue crack growth rate, J-integral, Alloy 800, fatigue (materials), crack propagation
Paper ID: STP34907S