Download or read book Numerical and Experimental Studies of Three dimensional Crack Evolution in Aluminum Alloys written by Ashley Dawn Spear and published by . This book was released on 2014 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a broad sense, the work described herein addresses either extreme of a traditional da/dN vs. dK plot. The first chapter addresses the uppermost limit of such plot, where tearing represents the limit state of structural failure. Subsequent chapters address the lower limit, where emphasis is placed on nucleation and early propagation of microstructurally small fatigue cracks (MSFCs). A common theme throughout the dissertation is the development of new tools and techniques (be they experimental or numerical) to enable unprecedented interrogation of crack evolution in 3D, with applications to various aluminum-alloy structures. Each chapter represents a separate body of work providing novel contributions in one or more areas involving fracture mechanics (viz. structural prognosis, corrosion science and engineering, and materials characterization). A brief overview of each chapter is described next. In Chapter 1, a methodology is described for predicting in real time the residual strength of structures with discrete-source damage. An artificial neural network (ANN) is trained using linear-elastic fracture mechanics (LEFM)-based data from numerical models; the ANN predicts residual strength given a set of damage parameters. Section 1.3 focuses on augmenting the existing LEFMbased modeling toolset to simulate ductile tearing and thereby improve resid- ual strength values used to train an ANN. Validation results are presented for two ductile-tearing simulations. Chapters 2 through 4 focus on MSFC initiation and propagation in an Al-Mg-Si alloy used to line composite-overwrapped pressure vessels. Chapter 2 describes an experimental study regarding the effect of an alkaline-based chemical milling treatment used to dimensionally reduce the Al-Mg-Si pressure-vessel liners. 3-D scanning electron microscopy is employed to quantify surface pitting caused by the chemical-milling treatment. The 3-D surface characteristics, along with high-magnification fractographs, are used to explain the observed 50% reduction in low-cycle fatigue lives among the chemically-milled specimens compared to a control group. In Chapter 3, an experimental methodology based on post-mortem measurements is developed to quantify 3-D rates of propagation and crack-surface crystallography for a naturally nucleated MSFC in an Al-Mg-Si specimen. The measurements are made possible through recent developments in 3-D characterization methods. Findings from the study demonstrate: 1) the complexity and variability of 3-D MSFC evolution in the Al-Mg-Si alloy and 2) the viability of the post-mortem characterization approach for quantifying 3-D MSFC evolution in polycrystalline alloys. The dissertation culminates with Chapter 4, which, for the first time, demonstrates the 3-D digital reconstruction and numerical simulation of a sequence of directly measured MSFCs, where both MSFC geometry and individual grain morphologies and orientations are explicitly represented at the polycrystalline length scale. The numerical reconstruction is demonstrated using 3-D measurements from Chapter 3. Work from Chapters 1 and 2 is published in [1, 2, 3, 4] and [5], respectively. The combined work from Chapters 3 and 4 is described in [6, 7, 8] and is currently in preparation for additional journal publication.
Download or read book Proceedings of the American Society for Composites 2014 Twenty ninth Technical Conference on Composite Materials written by Hyonny Kim and published by DEStech Publications, Inc. This book was released on 2014-09-17 with total page 3583 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and not previously published U.S. and international research on composite and nanocomposite materialsFocus on health monitoring/diagnosis, multifunctionality, self-healing, crashworthiness, integrated computational materials engineering (ICME), and moreApplications to aircraft, armor, bridges, ships, and civil structures This fully searchable CD-ROM contains 270 original research papers on all phases of composite materials, presented by specialists from universities, NASA and private corporations such as Boeing. The document is divided into the following sections: Aviation Safety and Aircraft Structures; Armor and Protection; Multifunctional Composites; Effects of Defects; Out of Autoclave Processing; Sustainable Processing; Design and Manufacturing; Stability and Postbuckling; Crashworthiness; Impact and Dynamic Response; Natural, Biobased and Green; Integrated Computational Materials Engineering (ICME); Structural Optimization; Uncertainty Quantification; NDE and SHM Monitoring; Progressive Damage Modeling; Molecular Modeling; Marine Composites; Simulation Tools; Interlaminar Properties; Civil Structures; Textiles. The CD-ROM displays figures and illustrations in articles in full color along with a title screen and main menu screen. Each user can link to all papers from the Table of Contents and Author Index and also link to papers and front matter by using the global bookmarks which allow navigation of the entire CD-ROM from every article. Search features on the CD-ROM can be by full text including all key words, article title, author name, and session title. The CD-ROM has Autorun feature for Windows 2000 or higher products and can also be used with Macintosh computers. The CD includes the program for Adobe Acrobat Reader with Search 11.0. One year of technical support is included with your purchase of this product.
Download or read book An Experimental and Numerical Investigation of Three Dimensional Crack Growth written by and published by . This book was released on 1989 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book Effects of Local Constraint Along Three Dimensional Crack Fronts a Numerical and Experimental Investigation written by Jonas Faleskog and published by . This book was released on 1994 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book A 3 dimensional Experimental and Numerical Analysis of the T E Integral in Aluminum Fracture Specimens written by John H. Jackson and published by . This book was released on 2001 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Japanese Science and Technology 1983 1984 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch and published by . This book was released on 1985 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1993 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)
Download or read book Fatigue and Fracture Mechanics written by Walter G. Reuter and published by ASTM International. This book was released on 2002-12-31 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the whole of Asia and the Pacific region, this text provides both an analytic overview and specific data for each of the 60 countries. Introductory chapters cover regional issues, including: a regional review with the year's trends, developments and key events' analysis of the threat of terrorism in the region; the effects of deflation on the economy; the water crisis and its impact on the poor; and the successes and failures of micro-credit in the region.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book A Numerical and Experimental Investigation of Stresses and Strains Around Crack Tips in High Strength Aluminium Alloys written by Nicholas George Allen and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book International Aerospace Abstracts written by and published by . This book was released on 1995 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering A Cumulative Index to the 1984 Issues of the Continuing Bibliography written by and published by . This book was released on 1985 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
