Book & CD. Fatigue of materials is very important in designing mechanical structures and components. Recently, fatigue databases, databanks and some computer software have been developed for fatigue analysis or fatigue life predictions, and some of them have been commercially available. Those fatigue databases and fatigue analysis software tools are clearly very helpful for the design and analysis engineers to select materials, analyse fatigue performance or estimate fatigue life of structures and components. In order to utilise those databases and software tools successfully in practice, engineers as users are implicitly required to have, more or less, wide and deep, and sometimes even advanced knowledge of fatigue; in other words, this book conveys considerable expertise in fatigue. However, most of the design and analysis engineers do not always have sufficient knowledge in fatigue and therefore, it is not yet easy for them to conduct fatigue design and analysis successfully, although there are many databases and software tools available. An expert system is a very useful, convenient and powerful tool for ordinary engineers to treat complicated engineering problems such as fatigue design and analysis, which require considerable expertise. Although the importance of fatigue expert systems has long been recognized, there is hardly any practically available fatigue expert system to date. Over many years, the authors have been developing some expert systems for fatigue assessment, particularly for the estimation of fatigue properties and for fatigue crack initiation life prediction under variable loading. Recently, in response to a scientific research result, the authors have developed a practically applicable version. They think that the expert system developed is probably the first and only fatigue expert system in the world. This book introduces in detail the expert systems developed and provides the expert system software, most probably in CD. Although it is not developed for commercial purposes, the system software is very easy to use. This book and the fatigue expert system software may be useful for nearly all engineers, researchers and technologists from the academic, industrial and government sectors who engage in engineering design and the maintenance of structures. This book is also designed for advanced undergraduate and beginning graduate-level engineering students in universities, particularly in the department of mechanical engineering, aerospace engineering, civil engineering and metallurgy.