Fatigue is probabilistic in nature and involves a complex spectrum of loading history with variable amplitudes and frequencies. Yet most available fatigue failure prediction methods are empirical and concentrate on very specific types of loading. Taking a different approach, this book provides a concise description of processes involving mechanical fatigue from the thermodynamics point of view. Drawing on recent cutting-edge research and development, the authors present an introduction to a unified entropic approach to fatigue. They introduce the fundamentals of fatigue processes and explore a wide range of practical engineering applications.