A round-robin analysis was conducted which evaluated and compared different methods currently in practice for predicting crack growth under random loading. This report describes the prediction method used by the Fracture Mechanics Engineering Section (FMES) at NASA-Langley Research Center. It also presents the ratios of the predicted lives to the test lives for eleven of the thirteen specimens tested.

Twenty-seven papers from fatigue researchers and practitioners review in detail recent progress in the development of methods to predict fatigue performance of materials and structures and to assess the extent to which these new methods are finding their way into practice. The papers, from the ASTM

This book offers a concise introduction to fatigue crack growth, based on practical examples. It discusses the essential concepts of fracture mechanics, fatigue crack growth under constant and variable amplitude loading and the determination of the fracture-mechanical material parameters. The book also introduces the analytical and numerical simulation of fatigue crack growth as well as crack initiation. It concludes with a detailed description of several practical case studies and some exercises. The target group includes graduate students, researchers at universities and practicing engineers.

The purpose of this Handbook is to provide a review of the knowledge and experiences in the field of fatigue fracture mechanics. It is well-known that engineering structures can fail due to cyclic loading. For instance, a cyclically time-varying loading reduces the structure strength and can provoke a fatigue failure consisting of three stages: (a) crack initiation (b) crack propagation and (c) catastrophic failure. Since last century many scientists have tried to understand the reasons for the above-mentioned failures and how to prevent them. This Handbook contains valuable contributions from leading experts within the international scientific community and covers many of the important problems associated with the fatigue phenomena in civil, mechanical and nuclear engineering.

This book demonstrates fatigue crack growth under random loading graphically. This state-of-the-art monograph introduces an expert system for crack growth predictions, particularly based on crack closure. The system is developed after years of research by the authors by using the Math-type software consisting of 5 parts. This system is unique as it is fundamentally different from previous systems as it focuses on fatigue crack growth predictions based on fatigue crack closure. This book can be a useful guide for practicing engineers, researchers, and students in the fields of mechanical, aerospace, or civil engineering.

Fatigue failure is a multi-stage process. It begins with the initiation of cracks, and with continued cyclic loading the cracks propagate, finally leading to the rupture of a component or specimen. The demarcation between the above stages is not well-defined. Depending upon the scale of interest, the variation may span three orders of magnitude. For example, to a material scientist an initiated crack may be of the order of a micron, whereas for an engineer it can be of the order of a millimetre. It is not surprising therefore to see that investigation of the fatigue process has followed different paths depending upon the scale of phenomenon under investigation. Interest in the study of fatigue failure increased with the advent of industrial ization. Because of the urgent need to design against fatigue failure, early investiga tors focused on prototype testing and proposed failure criteria similar to design formulae. Thus, a methodology developed whereby the fatigue theories were proposed based on experimental observations, albeit at times with limited scope. This type of phenomenological approach progressed rapidly during the past four decades as closed-loop testing machines became available.