Statistical Analysis of Fatigue Data


Book Description

It is commonly assumed in analysing fatigue data that there is a definite functional relationship between life in number of cycles and stress level. However, as has been pointed out several times (1, 2), an examination of the data shows considerable scatter. Even with carefully prepared smooth specimens, all from the same heat of steel, treated in the same manner and tested in the same laboratory, a range of 2 to 1 in number of cycles for failure at the same stress level is normal (1) and a range of 10 to 1 is not unusual (2). If the specimens are tested by different laboratories, slightly varying techniques will introduce further scatter (3).




Fatigue Testing and Analysis


Book Description

Fatigue Testing and Analysis: Theory and Practice presents the latest, proven techniques for fatigue data acquisition, data analysis, and test planning and practice. More specifically, it covers the most comprehensive methods to capture the component load, to characterize the scatter of product fatigue resistance and loading, to perform the fatigue damage assessment of a product, and to develop an accelerated life test plan for reliability target demonstration. This book is most useful for test and design engineers in the ground vehicle industry. Fatigue Testing and Analysis introduces the methods to account for variability of loads and statistical fatigue properties that are useful for further probabilistic fatigue analysis. The text incorporates and demonstrates approaches that account for randomness of loading and materials, and covers the applications and demonstrations of both linear and double-linear damage rules. The reader will benefit from summaries of load transducer designs and data acquisition techniques, applications of both linear and non-linear damage rules and methods, and techniques to determine the statistical fatigue properties for the nominal stress-life and the local strain-life methods. - Covers the useful techniques for component load measurement and data acquisition, fatigue properties determination, fatigue analysis, and accelerated life test criteria development, and, most importantly, test plans for reliability demonstrations - Written from a practical point of view, based on the authors' industrial and academic experience in automotive engineering design - Extensive practical examples are used to illustrate the main concepts in all chapters






















Fatigue of Structures and Materials


Book Description

This book is primarily a textbook. It is written for engineers, students and teachers, and it should also be useful for people working on various topics related to fatigue of structures and materials. The book can be used for graduate and undergraduate courses and for short courses for people already working in the industry, laboratories, or research institutes. Furthermore, the book offers various comments which can be useful to research-workers in order to consider the practical relevance of laboratory investigations and to plan future research. An important theme of the book is the understanding of what happens in the material of a structure in service if the structure is subjected to a spectrum of cyclic loads. Knowledge of the fatigue mechanism in the material and how it can be affected by a large variety of practical conditions is essential for dealing with fatigue problems. The designer of a dynamically loaded structure must “design against fatigue”. This includes not only the overall concept of the structure with related safety and economic aspects, but also questions on detail design, joints, production and material surface quality. At the same time, the designer must try to predict the fatigue performance of the structure. This requires a knowledge of the various influencing factors, also because predictions on fatigue have their limitations and shortcomings. Similar considerations arise if fatigue problems occur after a long period in service when decisions must be made on remedial actions.