This book provides practicing engineers, researchers, and students, with a working knowledge of the fatigue damage processes and models under multiaxial state of stress and strain. Readers are introduced to the important considerations of multiaxial fatigue that differentiate it from uniaxial fatigue. Multiaxial Fatigue presents an interpretive summary and comparison of various classes of models, providing a complete treatment of the subject from many perspectives. The concepts presented in this book are material independent and will be useful in designing test programs for metallic, ceramic, composite, and other materials. The book is filled with examples, case studies, and diagrams to make it a useful learning tool as well as a valuable desk reference. Contents include: State of Stress and Strain Stress-Strain Relationships Fatigue Damage Mechanisms Multiaxial Testing Nonproportional Loading Notches Strain-Based and Energy-Based Models Stress-Based Models Fracture Mechanics Model Applications.