Professor and director of the Structural Integrity Research Institute (SIRIUS), University of Sheffield, Sheffield,
Pages: 20 Published: Jan 1997
The three governing threshold conditions in metal fatigue are considered, one relating to crack growth in single crystals, one concerned with crack growth in polycrystalline materials, and one based on linear elastic fracture mechanics (LEFM).
All three conditions are examined in relation to the two physical processes of cracking, i.e., Stage I (shear) and Stage II (tensile) crack growth.
The LEFM threshold is seen as a lower bound condition for fatigue crack growth rate, and the single crystal threshold is viewed in relation to the fundamental threshold pertaining to the fatigue resistance of polycrystalline metals.
microstructural fracture mechanics, elastic-plastic fracture mechanics, linear elastic fracture mechanics, MFM threshold condition, LEFM threshold condition, single crystal threshold
Paper ID: STP16238S