A Comparative Review of Fatigue Modeling Approaches in Metals: From Total-Life Methods to Fracture-Based Models

Fatigue is widely recognized as one of the primary failure mechanisms affecting metallic structures. Consequently, reliable prediction of fatigue-induced failure is essential for the safe design and lifetime prediction of engineering structures and components. In this context, the present work provides an overview of some of the main approaches employed for fatigue modeling in metals. First, the classical total-life methods, namely the stress–life and strain–life approaches, are reviewed. Subsequently, fracture-based approaches to fatigue are presented, including formulations grounded in fracture mechanics, continuum damage mechanics, and phase-field theory. The finite element method and the extended finite element method are also discussed as representative numerical frameworks for the implementation of these formulations. The reviewed approaches are then critically compared in terms of their applicability, capabilities, limitations and calibration requirements. Finally, relevant directions for future research are identified.