Introduction
Outline This Thesis provides a collection of stress-life (S/N) models for fatigue life evaluation of both pristine and notched metallic components. The document is subdivided into five Chapters, the first being a Literature Overview of fatigue in general, and, in the specific, of the tools needed in the subsequent Chapters. In Chapter 2 the “crack like to blunt” notch transition is adapted to the stress-life approach using the theory of the critical distances, therefore a new S/N curve to model this transition is defined. Chapter 3 relies on the new S/N curve model for variable amplitude fatigue loading by demonstrating that fatigue life assessment under these conditions can be performed through a constant shift of the Wöhler curve if adopting a linear damage accumulation rule. The method is quite general since there is no need of hypothesizing specific constraints on loading history as the shift accounts for mean stress effects, al