Download or read book Elevated Temperature Process Zone Modeling of Small Cracks in Structural Ceramics Under Static and Cyclic Loading written by and published by . This book was released on 2000 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project focused on the study of the effects of microstructural features on the fracture process of high temperature structural ceramic materials that operate under cyclic loading environments. The ability to model these effects and the prediction of the deformation behavior also become an important consideration, as it provides a direct link to the design cycle for both, processing and design engineers. The project evaluated cyclic effects, high cycle fatigue behavior, and elevated temperature effects under these conditions. Evaluation of the effects of cyclic loading are performed using pre-cracked tensile test specimens (PFT) and bulk specimens by Moire Interferometry. Development of finite element and simple micromechanical models for predictions of the observed behavior also presented. It is observed that hysteretic load-displacement loops arise as the primary characteristic of the behavior, although gross-slip behavior is seen under certain circumstances.
Download or read book Fracture Process Zone Modeling of Small Cracks in Structural Ceramics Under Static and Cyclic Loading written by and published by . This book was released on 2000 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project focused on the study of the effects of microstructural features on the fracture process of high temperature structural ceramic materials that operate under cyclic loading environments. The ability to model these effects and the prediction of the deformation behavior also become an important consideration, as it provides a direct link to the design cycle for both, processing and design engineers. The project evaluated cyclic effects, high cycle fatigue behavior, and elevated temperature effects under these conditions. Evaluation of the effects of cyclic loading are performed using pre-cracked tensile test specimens (PFT) and bulk specimens by Moire Interferometry. Development of finite element and simple micromechanical models for predictions of the observed behavior also presented. It is observed that hysteretic load-displacement loops arise as the primary characteristic of the behavior, although gross-slip behavior is seen under certain circumstances.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Structural Integrity Cyclic loading and fatigue written by I. Milne and published by Elsevier. This book was released on 2003 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Advanced Ceramics written by Tatsuki Ohji and published by Elsevier Inc. Chapters. This book was released on 2013-04-11 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Process Zone Modeling of Elevated Temperature Structural Ceramics written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Post fracture tensile (PFT) experiments on two microstructures elucidated the crystallographic and microstructural contributions to the pullout resistance. In alumina, the average residual stresses arising from TEA diminish with increasing temperature, causing two effects evidenced by a general downward shift of the characteristic wake stress-displacement curves. Similar tests conducted on the cubic spinel exhibited no change in bridging efficiency. Similar experiments at the higher temperatures identify topographic changes of the fracture surface as the critical influence on the observed increased toughening behavior. Also, using the post fracture tensile (PFT) technique, the isolated wake region was tested in direct tension to determine the wake stiffness, offering further insight to those featured of the microstructure that control the bridging efficiency. From these studies, we found that alternate, more compliant micro-mechanisms must be included in the modeling effort to faithfully represent the relatively low measured wake stiffnesses.
Download or read book Concise Encyclopedia of Advanced Ceramic Materials written by R.J. Brook and published by Elsevier. This book was released on 2012-12-02 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced ceramics cover a wide range of materials which are ceramic by nature but have been developed in response to specific requirements. This encyclopedia collects together 137 articles in order to provide an up-to-date account of the advanced ceramic field. Some articles are drawn from the acclaimed Encyclopedia of Materials Science and Engineering, often revised, and others have been newly commissioned. The Concise Encyclopedia of Advanced Ceramic Materials aims to provide a comprehensive selection of accessible articles which act as an authoritative guide to the subject. The format is designed to help the readers form opinions on a particular subject. Arranged alphabetically, with a broad subject range, the articles are diverse in character and style, thereby stimulating further discussion. Topics covered include survey articles on glass, hot pressing, insulators, powders, and many are concerned with specific chemical systems and their origins, processing and applications. The Concise Encyclopedia of Advanced Ceramic Materials will be invaluable to materials scientists, researchers, educators and industrialists working in technical ceramics.
Download or read book Handbook of Advanced Ceramics written by Shigeyuki Somiya and published by Academic Press. This book was released on 2003-09-17 with total page 805 pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-volume reference set for all ceramicists, both in research and working in industry The only definitive reference covering the entire field of advanced ceramics from fundamental science and processing to application Contributions from over 50 leading researchers from around the world This new Handbook will be an essential resource for ceramicists. It includes contributions from leading researchers around the world, and includes sections on: Basic Science of Advanced Ceramic, Functional Ceramics (electro-ceramics and optoelectro-ceramics) and engineering ceramics.Contributions from over 50 leading researchers from around the world
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:
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1991 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Fatigue of Structural Ceramics written by and published by . This book was released on 1995 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the research effort was to establish a fundamental understanding of high temperature fatigue in structural ceramics. Two additional closely related areas, environmental effect on fatigue and temperature dependence on strength and toughness, were also targeted where basic understanding needed to be acquired. We were successful in establishing a comprehensive framework as the basis for understanding fatigue and fracture over a broad range of temperatures, static/cyclic loading conditions, and environmental conditions. The premises of that framework were: (1) Fatigue at low temperature is a process of mechanical balance in which resistance to crack advance is due to increased shielding whereas the impetus for crack advance is due to wear-caused degradation of crack wake shielding. (2) Fatigue at high temperature is a process of slow (creep) crack growth. Cyclic loading lowers the friction of grain boundary. The difference in crack growth rate in static and cyclic loadings can be rationalized by the different evolutions of crack-tip stress intensity factor under different grain boundary frictions. (3) Toughness in monolithic ceramics is due to grain pullout. jg p.1.
Download or read book High temperature Cyclic Fatigue and Fracture Properties in Silicon Nitride Structural Ceramics written by Alexander Ziegler and published by . This book was released on 1999 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Materials Processes written by and published by . This book was released on 1993-07 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The CRC Handbook of Mechanical Engineering written by D. Yogi Goswami and published by CRC Press. This book was released on 2004-09-29 with total page 2690 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of this standard-setting handbook provides and all-encompassing reference for the practicing engineer in industry, government, and academia, with relevant background and up-to-date information on the most important topics of modern mechanical engineering. These topics include modern manufacturing and design, robotics, computer engineering, environmental engineering, economics, patent law, and communication/information systems. The final chapter and appendix provide information regarding physical properties and mathematical and computational methods. New topics include nanotechnology, MEMS, electronic packaging, global climate change, electric and hybrid vehicles, and bioengineering.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fracture Process Zone Studies of High Temperature Structural Ceramics written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our work on this AFOSR-funded project successfully completed the PFT database through 1280#161#C for alumina and through 600#161#C for the magnesium aluminate spinel, elucidating the importance of crystal structure and fracture topography on the toughening characteristics. We now have a firm understanding of the relationship between the PFT method and the crack growth resistance curve, and are now developing further insights into the role of the microstructural constituents in the crack growth resistance behavior. A first-generation finite element model of the fracture specimen uses both the moire and PFT data to faithfully predict the bulk behavior. Our examination of the electronic speckle pattern interferometry (ESPI) system for elevated temperature measurements of the crack profile have been discontinued, due to inadequate resolution of the available control software. Therefore, the moire experiments are now being modified for elevated temperature studies. We are initiating a second-generation model of the pullout micromechanism to predict the stress-displacement relationship based on the crystal structure properties, grain size distribution, and elastic properties. In response to the detailed studies by the PFT technique, modified micromechanisms are now being incorporated into the model, including high compliance bridging ligaments, such as asperity loading, grain rotation and ligament bending.
