Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics Variable Load Conditions written by and published by . This book was released on 1992 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demands for structural systems to perform reliably under severe temperatures and load conditions continue to increase. These demands will continue with the development of advanced power generation methods and for future aerospace applications. An understanding of the hightemperature creep crack growth process, which is a frequent failure mechanism in these structures, is important. Many investigations which have appeared to date are concerned with creep crack growth which occurs under a constant load and temperature. However, most structural components experience complicated load histories. The history of degradation and damage which accumulates at the crack tip is greatly influenced by these transients. This program aims at gaining an understanding of the history-dependent high temperature failure process through a combined experimental and analytical effort. Development of a useful predictive methodology fbr characterizing this process is being undertaken.
Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics Variable Load Conditions Progress Report Phase 2 written by and published by . This book was released on 1992 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demands for structural systems to perform reliably under severe temperatures and load conditions continue to increase. These demands will continue with the development of advanced power generation methods and for future aerospace applications. An understanding of the hightemperature creep crack growth process, which is a frequent failure mechanism in these structures, is important. Many investigations which have appeared to date are concerned with creep crack growth which occurs under a constant load and temperature. However, most structural components experience complicated load histories. The history of degradation and damage which accumulates at the crack tip is greatly influenced by these transients. This program aims at gaining an understanding of the history-dependent high temperature failure process through a combined experimental and analytical effort. Development of a useful predictive methodology fbr characterizing this process is being undertaken.
Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics Phases I II and One Half of Phase III Variable Load Conditions Progress Report written by and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demands for structural systems to perform reliably under severe temperatures and load conditions continue to increase. These demands will continue with the development of advanced power generation methods, for aging nuclear and fossil fueled power plants, and for future aerospace applications. An understanding of the high-temperature creep crack growth process, which is a frequent failure mechanism in these structures, is important. Many investigations which have appeared to date are concerned with creep crack growth which occurs under a constant load and temperature. However, most structural components experience complicated load histories. The history of degradation and damage which accumulates at the crack tip is greatly influenced by these transients. This program aims at gaining an understanding of the history dependent high temperature failure process through a combined experimental and analytical effort. The development of a useful predictive methodology for characterizing this process is being undertaken.
Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics Phase 1 Constant Load Conditions Progress Report written by and published by . This book was released on 1991 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the following section a brief review of constitutive models is presented along with the implications of using them in creep crack growth studies under variable loads. The model searched for this study, is discussed along with is special features that make is particularly suitable for this investigation. This model is based on the creep hardening surface and is particularly useful for variable and fully reversed load histories. In Section 3 an implicit finite element algorithm for this model is derived. Details regarding implementation of this method into FVP and existing FE program to study creep crack growth, are also discussed. The results of the algorithm are verified against closed form solutions for simple geometries in Section 4. Sources of error and differences between using explicit and implicit schemes are also presented. Section 5 compares the numerical results with experimental data for the case of combined tension and torsion and fully reversed load histories. Section 6 provides results of some of the constant load creep crack growth analyses that have been performed to date. Because a wealth of experimental data has been developed for creep crack under constant load conditions, the need to develop our own creep growth data for this study was minimal. Conclusions of the Phase 1 work as well as work planned for the future are discussed in Section 7. Finally, Sections 8 and 9 discuss publications and the Phase 2 effort, respectively. Finally, the implementation of large strain and friction/contact algorithms into the finite element code and the implementation of three additional non-linear constitutive laws and the Walker Model are not discussed here. The large strain algorithm is complete, the endochronic theory is nearly complete, while subroutines for the Bodner and Walker models were obtained from the agencies described above.
Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics Phase 1 Constant Load Conditions written by and published by . This book was released on 1991 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the following section a brief review of constitutive models is presented along with the implications of using them in creep crack growth studies under variable loads. The model searched for this study, is discussed along with is special features that make is particularly suitable for this investigation. This model is based on the creep hardening surface and is particularly useful for variable and fully reversed load histories. In Section 3 an implicit finite element algorithm for this model is derived. Details regarding implementation of this method into FVP and existing FE program to study creep crack growth, are also discussed. The results of the algorithm are verified against closed form solutions for simple geometries in Section 4. Sources of error and differences between using explicit and implicit schemes are also presented. Section 5 compares the numerical results with experimental data for the case of combined tension and torsion and fully reversed load histories. Section 6 provides results of some of the constant load creep crack growth analyses that have been performed to date. Because a wealth of experimental data has been developed for creep crack under constant load conditions, the need to develop our own creep growth data for this study was minimal. Conclusions of the Phase 1 work as well as work planned for the future are discussed in Section 7. Finally, Sections 8 and 9 discuss publications and the Phase 2 effort, respectively. Finally, the implementation of large strain and friction/contact algorithms into the finite element code and the implementation of three additional non-linear constitutive laws and the Walker Model are not discussed here. The large strain algorithm is complete, the endochronic theory is nearly complete, while subroutines for the Bodner and Walker models were obtained from the agencies described above.
Download or read book An Investigation of the Effects of History Dependent Damage in Time Dependent Fracture Mechanics written by and published by . This book was released on 2002 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-temperature operation of technical engineering systems is critical for system efficiency, and will be a key driver in the future US DOE energy policy. Developing an understanding of high-temperature creep and creep-fatigue failure processes is a key driver for the research work described here. The focus is on understanding the high-temperature deformation and damage development on the nano-scale (50 to 500 nm) level. The high-temperature damage development process, especially with regard to low and high cyclic loading, which has received little attention to date, is studied. Damage development under cyclic loading develops in a fashion quite different from the constant load situation. The development of analytical methodologies so that high-temperature management of new systems can be realized is the key goal of this work.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Fracture Mechanics Time dependent fracture written by Ashok Saxena and published by ASTM International. This book was released on 1988 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Fracture Research written by K. Salama and published by Elsevier. This book was released on 2013-10-22 with total page 3063 pages. Available in PDF, EPUB and Kindle. Book excerpt: Held every four years, the International Congress on Fracture is the premier international forum for the exchange of ideas between scientists and engineers involved in producing and using materials resistant to fracture and fatigue. This major six-volume work which forms the proceedings of the Seventh International Congress on Fracture therefore provides the most comprehensive account available of the current status of research into fracture and fatigue, and the application of this knowledge to the design, fabrication and operation of materials and structures. As such, it will be an essential reference for materials scientists and mechanical, structural, aeronautical and design engineers with an interest in fracture and its prevention.
Download or read book Energy Materials Coordinating Committe EMaCC Fiscal Year 1996 Annual Technical Report written by and published by DIANE Publishing. This book was released on with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Materials Coordinating Committe EMaCC Fiscal Year 1997 Annual Technical Report written by and published by DIANE Publishing. This book was released on with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Corrosion in the Petrochemical Industry Second Edition written by and published by ASM International. This book was released on 2015-12-01 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in 1994, this second edition of Corrosion in the Petrochemical Industry collects peer-reviewed articles written by experts in the field of corrosion that were specifically chosen for this book because of their relevance to the petrochemical industry. This edition expands coverage of the different forms of corrosion, including the effects of metallurgical variables on the corrosion of several alloys. It discusses protection methods, including discussion of corrosion inhibitors and corrosion resistance of aluminum, magnesium, stainless steels, and nickels. It also includes a section devoted specifically to petroleum and petrochemical industry related issues.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Study of Micro scale Damage Evolution in Time Dependent Fracture Mechanics written by Joonyoung Oh and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In part 1, intergranular cavity growth in regimes, where both surface diffusion and deformation enhanced grain boundary diffusion are important, is studied. In order to continuously simulate the cavity shape evolution and cavity growth rate, a fully-coupled numerical method is proposed. Based on the fully-coupled numerical method, a gradual cavity shape change is predicted and this leads to the adverse effect on the cavity growth rate. As the portion of the cavity volume growth due to jacking and viscoplastic deformation in the total cavity volume growth increases, spherical cavity evolves to V-shaped cavity. The obtained numerical results are physically more realistic compared to results in the previous works. The present numerical results suggest that the cavity shape evolution and cavity growth rate based on the assumed cavity shape, spherical or crack-like, simply cannot be used in this regime. In part 2, intergranular creep failure of high temperature service material under a stress-controlled unbalanced cyclic loading condition is studied. The experimentally verified Murakami-Ohno strain hardening creep law and Norton's creep law are incorporated into the Tvegaard's axis-symmetric model for the constrained grain boundary rupture analysis. Based on the physically realistic Murakami-Ohno creep law, it is shown that the cavity growth becomes unconstrained upon the stress reversal from compression to tension. This leads to the prediction that the material life under a cyclic loading condition is shorter than that under a constant loading. Based on the classical Norton's law, the predicted material life under a cyclic loading condition remains the same as that under a constant loading. The obtained numerical results qualitatively match with recent experimental results by Arai, where the life under a cyclic loading can be much shorter than that under a constant loading. There are many cases where engineers use a simple Norton's creep law because of its simplicity. The present work suggests that more physically realistic creep laws should be used when cyclic loading must be considered.
Download or read book Integrated Computational Materials Engineering ICME for Metals written by Mark F. Horstemeyer and published by John Wiley & Sons. This book was released on 2012-06-07 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: State-of-the-technology tools for designing, optimizing, and manufacturing new materials Integrated computational materials engineering (ICME) uses computational materials science tools within a holistic system in order to accelerate materials development, improve design optimization, and unify design and manufacturing. Increasingly, ICME is the preferred paradigm for design, development, and manufacturing of structural products. Written by one of the world's leading ICME experts, this text delivers a comprehensive, practical introduction to the field, guiding readers through multiscale materials processing modeling and simulation with easy-to-follow explanations and examples. Following an introductory chapter exploring the core concepts and the various disciplines that have contributed to the development of ICME, the text covers the following important topics with their associated length scale bridging methodologies: Macroscale continuum internal state variable plasticity and damage theory and multistage fatigue Mesoscale analysis: continuum theory methods with discrete features and methods Discrete dislocation dynamics simulations Atomistic modeling methods Electronics structures calculations Next, the author provides three chapters dedicated to detailed case studies, including "From Atoms to Autos: A Redesign of a Cadillac Control Arm," that show how the principles and methods of ICME work in practice. The final chapter examines the future of ICME, forecasting the development of new materials and engineering structures with the help of a cyberinfrastructure that has been recently established. Integrated Computational Materials Engineering (ICME) for Metals is recommended for both students and professionals in engineering and materials science, providing them with new state-of-the-technology tools for selecting, designing, optimizing, and manufacturing new materials. Instructors who adopt this text for coursework can take advantage of PowerPoint lecture notes, a questions and solutions manual, and tutorials to guide students through the models and codes discussed in the text.
Download or read book Engine Structures written by and published by . This book was released on 1988 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
