The High Frequency Fatigue Behavior of Continuous Fiber Reinforced Ceramic Matrix Composites PDF Download

Author: Nikhilesh Chawla
Publisher:
ISBN:
Category : Ceramic-matrix composites
Languages : en
Pages : 166

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Author: Nikhilesh Chawla
Publisher:
ISBN:
Category :
Languages : en
Pages : 380

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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The AFOSR funded two year project (which expires March 1, 1997) addresses the effect of loading frequency and friction heating on the ambient temperature fatigue life of continuous fiber ceramic matrix composites (CFCMCs). The project, which involves mechanics modeling, mechanical testing and microscopy, examined several composite systems and has provided details concerning the damage mechanisms that occur during high frequency fatigue. The current research effort of high-frequency fatigue has been performed at the Ceramic Composites Research laboratory, in the Mechanical Engineering and applied Mechanics Department at the University of Michigan. 1. "Soft" matrix composites with strong interface bonding were shown to provide superior resistance to high frequency fatigue damage. 2. thick fiber coatings were more effective in reducing the amount of fiber wear and damage which occur during high frequency fatigue. 3. The effect of laminate stacking sequence has a profound effect on high frequency fatigue behavior of CFCMCs. 4. Surface roughness in Nicalon fibers can be determined using Atomic force Microscopy (AFM). 5. Elongated crystalline grains and a small volume fraction of whiskers in the matrix can improve the high frequency fatigue behavior of CFCMCs. 6. Loading rate was found to significantly effect monotonic tensile behavior of CFCMCs.

Author: Longbiao Li
Publisher: John Wiley & Sons
ISBN: 3527822607
Category : Technology & Engineering
Languages : en
Pages : 749

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Guides researchers and practitioners toward developing highly reliable ceramic-matrix composites The book systematically introduces the thermomechanical fatigue behavior of fiber-reinforced ceramic-matrix composites (CMCs) and environmental barrier coatings, including cyclic loading/unloading tensile behavior, cyclic fatigue behavior, dwell-fatigue behavior, thermomechanical fatigue behavior, and interface degradation behavior. It discusses experimental verification of CMCs and explains how to determine the thermomechanical properties. It also presents damage evolution models, lifetime prediction methods, and interface degradation rules. Thermomechanical Fatigue of Ceramic-Matrix Composites offers chapters covering unidirectional ceramic-matrix composites and cross-ply and 2D woven ceramic-matrix composites. For cyclic fatigue behavior of CMCs, it looks at the effects of fiber volume fraction, fatigue peak stress, fatigue stress ratio, matrix crack spacing, matrix crack mode, and woven structure on fatigue damage evolution. Both the Dwell-fatigue damage evolution and lifetime predictions models are introduced in the next chapter. Experimental comparisons of the cross-ply SiC/MAS composite, 2D SiC/SiC composite, and 2D NextelTM 720/Alumina composite are also included. Remaining sections examine: thermomechanical fatigue hysteresis loops; in-phase thermomechanical fatigue damage; out-of-phase thermomechanical fatigue; interface degradation models; and much more. -Offers unique content dedicated to thermomechanical fatigue behavior of ceramic-matrix composites (CMCs) and environmental barrier coatings -Features comprehensive data tables and experimental verifications -Covers a highly application-oriented subject?CMCs are being increasingly utilized in jet engines, industrial turbines, and exhaust systems Thermomechanical Fatigue of Ceramic-Matrix Composites is an excellent book for developers and users of CMCs, as well as organizations involved in evaluation and characterization of CMCs. It will appeal to materials scientists, construction engineers, process engineers, and mechanical engineers.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Cyclic tension-tension experiments were conducted on a ceramic matrix composite of continuous Nicalon SiC-fibers in a calcium-aluminosilicate matrix. Two different stress ratios (R = sigma(min)/sigma(max)) were studied (R = 0.5 and R = 0.05) at a loading frequency of 200 Hz. Specimens tested at R = 0.05 were found to have a shorter fatigue life than specimens tested at R = 0.5. The fatigue limit (defined as run-out at 10(exp 8) cycles) increased from 212 MPa for R = 0.05 to 240 MPa for R = 0.5. Microstructural investigations revealed an internal zone with no fiber pull-out at the fracture surface, suggesting that the fatigue failures occur due to internal embrittlement. The loading condition with smallest stress range (i.e., the largest stress ratio) has the lowest amount of interfacial sliding (and thus the lowest frictional energy dissipation). It is therefore plausible that the fatigue damage is related to the amount of interfacial sliding.

Author: Michael G. Jenkins
Publisher: ASTM International
ISBN: 0803120338
Category : Ceramics
Languages : en
Pages : 315

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Author: Yahya K. Tür
Publisher:
ISBN:
Category :
Languages : en
Pages : 210

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Author: Longbiao Li
Publisher: Springer
ISBN: 9811317836
Category : Technology & Engineering
Languages : en
Pages : 249

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This book focuses on the damage, fracture and fatigue of ceramic-matrix composites. It investigates tensile damage and fracture, fatigue hysteresis, and the properties of interfaces subjected to cyclic fatigue loading. Further, it predicts fatigue life at room and elevated temperatures using newly developed damage models and methods, and it analyzes and compares damage, fracture and fatigue behavior of different fiber performs: unidirectional, cross-ply, 2D and 2.5D woven. The developed models and methods can be used to predict the damage and lifetime of ceramic-matrix composites during applications on hot section components.Ceramic-matrix composites (CMCs) are high-temperature structural materials with the significant advantages of high specific strength, high specific modulus, high temperature resistance and good thermal stability, which play a crucial role in the development of high thrust weight ratio aero engines. The critical nature of the application of these advanced materials makes comprehensive characterization a necessity, and as such this book provides designers with essential information pertaining not only to the strength of the materials, but also to their fatigue and damage characteristics.

Author: Narendernath Miriyala
Publisher:
ISBN:
Category :
Languages : en
Pages : 564

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Author: K.L. Reifsnider
Publisher: Elsevier
ISBN: 0444597182
Category : Technology & Engineering
Languages : en
Pages : 532

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Book Description
This book provides the first comprehensive review of its kind on the long-term behaviour of composite materials and structures subjected to time variable mechanical, thermal, and chemical influences, a subject of critical importance to the design, development, and certification of high performance engineering structures. Specific topics examined include damage, damage characterization, and damage mechanics; fatigue testing and evaluation; fatigue behaviour of short and long fibre reinforced polymer and metal matrix materials; viscoelastic and moisture effects; delamination; statistical considerations; the modeling of cumulative damage development; and life prediction. The volume provides an extensive presentation of data, discussions, and comparisons on the behaviour of the major types of material systems in current use, as well as extensive analysis and modeling (including the first presentation of work not found elsewhere). The book will be of special interest to engineers concerned with reliability, maintainability, safety, certification, and damage tolerance; to materials developers concerned with making materials for long-term service, especially under severe loads and environments, and to lecturers, students, and researchers involved in material system design, performance, solid mechanics, fatigue, durability, and composite materials. The scope of the work extends from entry level material to the frontiers of the subject.