Propagation and Non-Propagation of Small Fatigue Cracks

摘要

An inherent damage zone model is presented to explain the fatigue properties of small sized cracks near the fatigue limit and the crack growth threshold. A special feature of the paper is using the exact stress distributions of notched and cracked specimens at the strength evaluations. analytical solutions by Neuber and Westergaard are employed for this purpose. A crack propagation law is newly developed based on the inherent damage zone model. The propagation rate of small sized fatigue cracks, the effect of crack length on threshold strength, the occurrence condition of non-propagating crack in sharp notched specimen, etc. are evaluated and compared with the previous experimental results.