Book excerpt: An Introduction to Fatigue in Metals and Composites provides a balanced treatment of the phenomenon of fatigue in metals, nonmetals and composites with polymeric, metallic and ceramic matrices. The applicability of the safe life philosophy of design is examined for each of the materials. Attention is also focused on the stable crack growth phase of fatigue and differences in the operative mechanisms for the various classes of materials are considered. The impacts of these differences on the development of damage tolerance strategies are examined. Among topics discussed are; variable amplitude loading with tensile and compressive overload; closure obstruction; bridging mechanisms; mixed mode states; small cracks; delamination mechanisms and environmental conditions. The arrangement and presentation of the topics are such that An Introduction to Fatigue in Metals and Composites can serve as a course text for mechanical, civil, aeronautical and astronautical engineering and material science courses as well as a reference for engineers who are concerned with fatigue testing and aircraft, automobile and engine design.