Advanced Photon Source –Argonne National Laboratory, Argonne, Illinois, USA

摘要

A series of replicas taken periodically throughout the fatigue lifetime has been used to determine the fraction of lifetime in the high cycle range at which a fatigue crack can be first identified. For the alloys investigated this fraction is less than 10% of the fatigue lifetime. The replicas also provide a record of crack length as a function of the number loading cycles, and this information has been used to compare the crack length with predictions based upon a basic constituitive relationship. Good agreement between the experimental results and the predictions was obtained.