Statistical Aspects of Fatigue at Microscopic, Specimen, and Component Levels
SourceThe study of fatigue mechanisms at the microscopic level is examined. The complexity of the microstructure and the availability of quantitative microscopy concepts created a need to introduce statistical tools to the fundamental aspects of fatigue research. Examples of the corrosion fatigue of high-strength steel, the bending fatigue of currency paper, and the swelling of nuclear fuel elements are used to illustrate this new viewpoint. The statistical concept of stress in a medium with distributed voids or other geometric imperfections is introduced to permit the use of models different from the conventional continuum viewpoint. The concept of a nested model and the incorporation of a size effect in the study of fatigue at three microscopic levels and three macroscopic (specimen, component, structure) levels are discussed.