Download or read book Fatigue Crack Closure Evaluation Under Constant Amplitude and Spectrum Loading written by BK. Parida and published by . This book was released on 2003 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth behavior of through-the-thickness cracks emanating from the notch root in an aluminum alloy was investigated with particular emphasis on the evaluation of crack closure and its effects on fatigue crack growth rate. The tests were performed on SE(T) specimens both under constant amplitude (CA) and spectrum (modified FALSTAFF) loads. The near-tip strain measurement method was used for crack closure estimation in the short and long crack ranges. An attempt was also made to determine the crack closure value corresponding to the crack-tip shielding through fractographic analysis.
Download or read book Fatigue Crack Growth Under Spectrum Loads written by Ralph Ivan Stephens and published by ASTM International. This book was released on 1976 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Fatigue Crack Closure Measurement and Analysis written by R. Craig McClung and published by ASTM International. This book was released on 1999 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction of Fatigue crack Growth Under Variableamplitude and Spectrum Loading Using a Closure Model written by and published by . This book was released on 1981 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Crack closure Model for Predicting Fatigue crack Growth Under Aircraft Spectrum Loading written by and published by . This book was released on 1981 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanics of Fatigue Crack Closure written by Wolf Elber and published by ASTM International. This book was released on 1988 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crack Growth Under Spectrum Loading A Crack Closure Model written by and published by . This book was released on 1975 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concept based on the crack-closure phenomenon was developed to replace random load spectra with constant amplitude loading in both analysis and tests. The maximum load and the crack opening load in the constant amplitude loading are chosen to be equal to those for the spectrum, so that both crack growth mode and the crack length at failure are equivalent to those under random load spectra. The number of cycles of constant- amplitude loading is chosen so that the amount of crack growth is equal to that due to a given sequence or block of the random spectrum loading. The concept was tested experimentally after predicting the equivalent number of constant-amplitude cycles for six different random load sequences. The agreement between predictions and test results was good.
Download or read book Role of Crack Closure Mechanisms on Fatigue Crack Growth of Ti 62222 Under Constant Amplitude and Transient Loading at 54 25 and 175 C written by SG. Berge and published by . This book was released on 1999 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth behavior of Ti-62222 in sheet form was investigated at three temperatures under various load histories with a specific emphasis on crack opening measurements and mechanisms. Constant-amplitude R = 0.1 near-threshold results showed that based upon applied ?K, fatigue crack growth rates were lower at the two temperature extremes in comparison with those at room temperature. Based upon ?Keff, a moderate temperature effect was observed. The various shifts in the ?Keff curves were a result of different controlling crack closure mechanisms at each temperature. Single tensile overloads at 2.5 x Kmax produced a delay in fatigue crack growth and was most significant at -54°C. Remote crack opening measurements showed no appreciable change during the delay period due to the small region along the crack front that experienced crack closure. Near crack tip opening measured for various combinations of overloads, underloads, and constant ?K at 25°C revealed a general trend for higher near tip opening following a tensile overload. However, a sufficient number of measurements were inconsistent and thus only minimal confidence could be placed with the method. Scanning electron microscopy was used to evaluate surface fatigue crack growth profiles and fatigue crack growth fracture surface morphology.
Download or read book Advances in Fatigue Lifetime Predictive Techniques written by Michael R. Mitchell and published by ASTM International. This book was released on 1992 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book An Evaluation of the Plasticity Induced Crack Closure Concept and Measurement Methods written by James C. Newman (Jr.) and published by . This book was released on 1998 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Crack Closure Model for Predicting Fatigue Crack Growth Under Aircraft Spectrum Loading written by JC. Newman and published by . This book was released on 1981 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments on metallic materials have shown that fatigue cracks remain closed during part of the load cycle under constant- and variable-amplitude loading. These experiments have shown that crack closure is a significant factor in causing load-interaction effects (retardation and acceleration) on crack growth rates under variable-amplitude loading.
Download or read book Fatigue of Structures and Materials written by J. Schijve and published by Springer Science & Business Media. This book was released on 2008-12-16 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Analysis of Fatigue Crack Growth in Terms of Crack Closure and Energy written by N. Ranganathan and published by . This book was released on 1999 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack growth behavior of the aluminum alloy 2024 is analyzed using the crack closure and an energy-based concept. The different test conditions studied include load ratio and environmental effects, crack growth retardation following a single overload, and crack propagation under block load tests. Crack opening loads using the compliance technique permit the effect of load ratio to be taken into account. After an overload, in the deceleration phase, the evolution of the crack opening load is not compatible with that of the crack growth rate. The measured crack opening levels under constant-amplitude loading conditions are comparable to those predicted under plane strain conditions for moderate ?K levels. It is shown that most of the effects usually attributed to closure can be successfully explained using energy concepts. In particular, it is shown that there exists a linear relationship between the crack growth rate and the energy dissipated per cycle at high growth rates, which is valid for both the environments studied, and it corresponds to a crack growth mechanism characterized by striation formation during each cycle. For lower growth rates a power law relationship can be proposed between these two parameters. The above-mentioned linear relationship holds also for the block loading conditions based on total energy dissipated per block. Certain experimental facts bring out the effect of closure on the energy dissipated. It is further shown that the possible existence of a mixed (Mode I and Mode II) mode crack opening at the crack tip has to be taken into account to correctly evaluate the energy dissipated near the crack tip.
Download or read book Measurement and Analysis of Critical Crack Tip Processes During Fatigue Crack Growth written by and published by . This book was released on 1985 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Significance of Fatigue Crack Closure written by W. Elber and published by . This book was released on 1971 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments on 2024-T3 aluminum alloy sheet are described which confirm the occurrence of fatigue crack closure under cyclic tensile loading. The results show that a fatigue crack can be closed at the crack tip for up to half of the loading amplitude, leaving this portion of the cycle ineffective in propagating the crack. An expression for the crack propagation rate in terms of effective stress amplitude is proposed. This expression is fitted to existing constant amplitude crack propagation data for 2024-T3 aluminum alloy. The parameters evaluated provide a better fit to the data than other empirical expressions available. Analysis of qualitative experiments on variable amplitude loading shows that the crack closure phenomenon could account for acceleration and retardation effects in crack propagation.
Download or read book Expert System for Fatigue Crack Growth Predictions Based on Fatigue Crack Closure written by Ji-Ho Song and published by Springer Nature. This book was released on 2022-03-04 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Equivalent Constant Amplitude Concept for Crack Growth Under Spectrum Loading written by W. Elber and published by . This book was released on 1976 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concept based on the crack-closure phenomenon has been developed to replace random-load spectra with constant-amplitude loading in both analysis and tests. The maximum load and the crack-opening load in the constant-amplitude loading are chosen to be equal to those for the spectrum, so that both crack-growth mode and the crack length at failure are equivalent to those under the random-load spectra. The number of cycles of constant-amplitude loading is chosen so that the amount of crack growth is equal to that due to a given sequence or block of the random spectrum loading. The concept was tested experimentally after predicting the equivalent number of constant-amplitude cycles for six different random-load sequences. The agreement between predictions and test results was good.
