[PDF] On The Prediction Of Fatigue Life Under Random Loading eBook
On The Prediction Of Fatigue Life Under Random Loading Book in PDF, ePub and Kindle version is available to download in english. Read online anytime anywhere directly from your device. Click on the download button below to get a free pdf file of On The Prediction Of Fatigue Life Under Random Loading book. This book definitely worth reading, it is an incredibly well-written.
A review is given of some current methods of estimating fatigue damage and a new damage equation is derived based on the work of Corten and Dolan, and Torbe. This equation is applied to the case of a stationary Gaussian stress history and a discussion is given of the parameters appearing in the resulting equation for the fatigue life. (Author).
Each of a number of aluminum-alloy test specimens was loaded by random forces at a constant root-mean-square stress level until rupture occurred. The forces were statistically stationary and Gaussian with a zero mean value. The fatigue life (to rupture) was determined for various values of the following statistical parameters: (a) root-mean-square nominal applied stress, (b) power spectral shape, (c) mean number of zero crossings per unit time, and (d) mean number of peak loads per unit time. The power spectra were varied over a passband of frequency for three spectral shapes either by holding the power constant with frequency or by varying it either directly or inversely proportional to the square of the frequency. The results indicate that the fatigue life was determined principally by the root-mean-square nominal applied stress level. The effects of spectral shape, average number of zero crossings, and average number of peak loads were insignificant in the ranges investigated. The fatigue life, based on the number of effective cycles, of the specimens under random loading was lower by at least an order of magnitude at all stress levels than that of the specimens loaded sinusoidally. A linear cumulative damage theory overestimated the fatigue life, especially at low stress levels. The fracture characteristics of the specimens which failed under random loading were similar to those which failed under sinusoidal loads.
This book provides practicing engineers, researchers, and students with a working knowledge of the fatigue design process and models under multiaxial states of stress and strain. Readers are introduced to the important considerations of multiaxial fatigue that differentiate it from uniaxial fatigue.
Fatigue Life Prediction of Composites and Composite Structures, Second Edition, is a comprehensive review of fatigue damage and fatigue life modeling and prediction methodologies for composites and their use in practice. In this new edition, existing chapters are fully updated, while new chapters are introduced to cover the most recent developments in the field. The use of composites is growing in structural applications in many industries, including aerospace, marine, wind turbine and civil engineering. However, there are uncertainties about their long-term performance, including performance issues relating to cyclic fatigue loading that hinder the adoption of a commonly accepted credible fatigue design methodology for the life prediction of composite engineering structures. With its distinguished editor and international team of contributors, this book is a standard reference for industry professionals and researchers alike. Examines past, present and future trends associated with the fatigue life prediction of composite materials and structures Assesses novel computational methods for fatigue life modeling and prediction of composite materials under constant amplitude loading Covers a wide range of techniques for predicting fatigue, including their theoretical background and practical applications Addresses new topics and covers contemporary research developments in the field
Fatigue of structures and materials covers a wide scope of different topics. The purpose of the present book is to explain these topics, to indicate how they can be analyzed, and how this can contribute to the designing of fatigue resistant structures and to prevent structural fatigue problems in service. Chapter 1 gives a general survey of the topic with brief comments on the signi?cance of the aspects involved. This serves as a kind of a program for the following chapters. The central issues in this book are predictions of fatigue properties and designing against fatigue. These objectives cannot be realized without a physical and mechanical understanding of all relevant conditions. In Chapter 2 the book starts with basic concepts of what happens in the material of a structure under cyclic loads. It illustrates the large number of variables which can affect fatigue properties and it provides the essential background knowledge for subsequent chapters. Different subjects are presented in the following main parts: • Basic chapters on fatigue properties and predictions (Chapters 2–8) • Load spectra and fatigue under variable-amplitude loading (Chapters 9–11) • Fatigue tests and scatter (Chapters 12 and 13) • Special fatigue conditions (Chapters 14–17) • Fatigue of joints and structures (Chapters 18–20) • Fiber-metal laminates (Chapter 21) Each chapter presents a discussion of a speci?c subject.
Preliminary tests were made to investigate a method of fatigue life prediction in which fatigue data obtained under a simple form of random loading are substituted for the data hitherto obtained under sinusoidal test conditions. The results of this work show a significant increase in the accuracy of prediction, but it is evident that further allowance for load interaction effects is necessary, if greater accuracy is to be obtained. (Author).
Understand why fatigue happens and how to model, simulate, design and test for it with this practical, industry-focused reference Written to bridge the technology gap between academia and industry, the Metal Fatigue Analysis Handbook presents state-of-the-art fatigue theories and technologies alongside more commonly used practices, with working examples included to provide an informative, practical, complete toolkit of fatigue analysis. Prepared by an expert team with extensive industrial, research and professorial experience, the book will help you to understand: Critical factors that cause and affect fatigue in the materials and structures relating to your work Load and stress analysis in addition to fatigue damage-the latter being the sole focus of many books on the topic How to design with fatigue in mind to meet durability requirements How to model, simulate and test with different materials in different fatigue scenarios The importance and limitations of different models for cost effective and efficient testing Whilst the book focuses on theories commonly used in the automotive industry, it is also an ideal resource for engineers and analysts in other disciplines such as aerospace engineering, civil engineering, offshore engineering, and industrial engineering. The only book on the market to address state-of-the-art technologies in load, stress and fatigue damage analyses and their application to engineering design for durability Intended to bridge the technology gap between academia and industry - written by an expert team with extensive industrial, research and professorial experience in fatigue analysis and testing An advanced mechanical engineering design handbook focused on the needs of professional engineers within automotive, aerospace and related industrial disciplines
This monograph examines the theoretical foundations of the spectral method for fatigue life determination. The authors discuss a rule of description of random loading states with the matrix of power spectral density functions of the stress/strain tensor components. Some chosen criteria of multiaxial fatigue failure are analyzed. The formula proposed in this book enables readers to determine power spectral density of the equivalent history directly from the components of the power spectral density matrix of the multidimensional stochastic process.