Download or read book Fracture Micromechanics as Influenced by Environment in Textile Reinforced Ceramic Matrix Composites written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research was a basic understanding of the factors that contribute to the fracture toughness of fabric reinforced ceramic matrix composites (CMCs). A technique was developed for measuring the fracture toughness of fabrics. The mechanical properties of matrix materials were measured using a Nanoindenter, and found to be low compared to the properties expected from matrix composition. Crack tip micromechanics, i.e., crack opening displacements and strains near the crack tip, were measured both for fabrics and from CMCs. It was found that fiber bundles move relative to each other during fracture, and that voids in the material accommodate that motion. The ability of fiber bundles to move is believed to be an important factor in developing a high fracture toughness in these materials. A finite element model was developed to simulate fabric fracture and the effects of an including matrix to form a composite. Exposure to air and Argon at 1100 deg C for 146 hrs. resulted in a decrease in fracture toughness of several composites evaluated. Micromechanics evaluation found no differences that could be attributed to the gas environment, so it was concluded that fiber strength degradation was the cause of lower fracture toughness.

Download or read book Fracture Micromechanics of Continuous Fiber and Textile Reinforced Metal and Ceramic Matrix Composites written by and published by . This book was released on 1994 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes progress on fatigue crack growth through unidirectional SCS-6/titanium alloy composites and the fatigue and fracture of ceramic matrix composites reinforced with continuous fibers, both large and small, in unidirectional and woven forms. The fiber/matrix interaction is detailed for SCS-6/titanium alloy composites near stress concentrations, and it is shown how that is similar to measurements of fiber stress in the wake of fatigue cracks. The main theme of the work on ceramic matrix composites is the effect of fiber architecture on fatigue behavior. Metal matrix composites, Ceramic matrix composites, Continuous fiber reinforcement, Fatigue crack growth, Crack growth mechanisms, Woven fiber reinforcement.

Download or read book Micromechanics of Ceramic Matrix Composites at Elevated Temperatures written by Longbiao Li and published by Springer Nature. This book was released on with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the ASME Textile Engineering Division written by and published by . This book was released on 2004 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Micromechanics fatigue damage analysis modeling for fabric reinforced ceramic matrix composites written by D. Xue and published by . This book was released on 2013 with total page 21 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 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Textile Technology Digest written by and published by . This book was released on 2000 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Damage Fracture and Fatigue of Ceramic Matrix Composites written by Longbiao Li and published by Springer. This book was released on 2018-08-27 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Time Dependent Mechanical Behavior of Ceramic Matrix Composites at Elevated Temperatures written by Longbiao Li and published by Springer Nature. This book was released on 2020-04-18 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates the time-dependent behavior of fiber-reinforced ceramic-matrix composites (CMCs) at elevated temperatures. The author combines the time-dependent damage mechanisms of interface and fiber oxidation and fracture with the micromechanical approach to establish the relationships between the first matrix cracking stress, matrix multiple cracking evolution, tensile strength, tensile stress-strain curves and tensile fatigue of fiber-reinforced CMCs and time. Then, using damage models of energy balance, the fracture mechanics approach, critical matrix strain energy criterion, Global Load Sharing criterion, and hysteresis loops he determines the first matrix cracking stress, interface debonded length, matrix cracking density, fibers failure probability, tensile strength, tensile stress-strain curves and fatigue hysteresis loops. Lastly, he predicts the time-dependent mechanical behavior of different fiber-reinforced CMCs, i.e., C/SiC and SiC/SiC, using the developed approaches, in order to reduce the failure risk during the operation of aero engines. The book is intended for undergraduate and graduate students who are interested in the mechanical behavior of CMCs, researchers investigating the damage evolution of CMCs at elevated temperatures, and designers responsible for hot-section CMC components in aero engines.

Download or read book High Temperature Micromechanics and Mechanisms of Damage and Failure in Advanced Ceramic Matrix Composites written by and published by . This book was released on 2000 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, research efforts have been made to address some of the most critical and complex issues on high-temperature damage, degradation and failure of advanced composites. For the convenience of program planning and execution, the research as been formulated in the form of several interrelated technical tasks with distinct focuses. In the study of high-temperature ceramic-matrix the following tasks have been conducted: (1) High-temperature fiber/matrix interface properties and failure mechanics; (2) High-temperature micromechanics theories for thermoelastic constitutive equations for whisker-reinforced ceramic composites with large temperature traverse; (3) High-temperature creep deformation and micromechanics modeling of inelastic composite constitutive properties with composite microstructure and damage, and (4) High-temperature toughening mechanisms, and mechanics of crack growth fracture. For the high-temperature polymer-matrix composite study, the following thermomechanics issues with internal and external damage have been addressed: (1) thermal oxidation reaction and stability at elevated temperatures; (2) chemical and physical aging in extreme thermal environments; (3) microstructure changes and property degradation associated with aging at elevated temperatures; and (4) long-term thermomechanical creep and associated damage modes.

Download or read book Fracture Micromechanics of Intermetallic and Ceramic Matrix Continuous Fiber Composites written by and published by . This book was released on 1991 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micromechanics parameters for fatigue cracks growing perpendicular to fibers were measured through small port holes in the matrix made by electropolishing, were used to determine fiber stresses, which ranged from 1.1 to 4 GPa. Crack opening displacements at maximum load and residual crack opening displacements (at minimum load) were measured. Matrix was removed along the crack flanks after completion of the tests to reveal the extent and nature of fiber damage. Analyses were made of these parameters, and it was found possible to link the extent of fiber debonding to residual COD and the shear stress for debonding, estimated at 245 MPa, to COD. Measured experimental parameters were used to compute crack growth rates using a wall known fracture mechanics model for fiber bridging tailored to these experiments. The potential for microstructural manipulation to yield further increases in fatigue crack growth resistance for the metals and alloys currently being used in gas turbine construction is small. Studies of fatigue crack growth through aluminum, titanium and superalloys have shown that there are many similarities in the mechanisms of crack growth and the crack tip micromechanics for these materials. Conversely, composite materials reinforced with continuous strong fibers offer the promise of drastic increases in fatigue crack growth resistance.

Download or read book Ceramic Matrix Composites written by J. Paulo Davim and published by Walter de Gruyter GmbH & Co KG. This book was released on 2016-06-20 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite materials are engineered from two or more constituents with significantly altered physical or chemical properties within the finished structure. Due to their special mechanical and physical properties they have the potential to replace conventional materials. This book, written by experts from all over the world, presents fundamentals and recent advances on ceramic matrix composites.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1992 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comprehensive Study of Matrix Fracture Mechanisms in Fiber Reinforced Ceramic Matrix Composites written by and published by . This book was released on 1993 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final technical report summarizes the activities, accomplishment and research results obtained under the research grant AFOSR-90-0712, which covered the period from 15 February 1990 to 30 April 1993. The main objective of the research is to study the physical mechanisms of matrix microcracking which constitutes the fundamental cause for the toughness and strength properties in fiber-reinforced ceramic-matrix composites. Major results summarized in this report include (1) fabrication of the test specimens with controlled microstructural variables; (2) laboratory tests of matrix microcracking with in- situ and real-time monitoring; and (3) formulation of a simulation model and modeling results. A list of publications that have resulted from this research is included in this report.

Download or read book Damage and Fracture of Ceramic Matrix Composites Under Stochastic Loading written by Longbiao Li and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the relationships between tensile damage and fracture, fatigue hysteresis loops, stress-rupture, fatigue life and fatigue limit stress, and stochastic loading stress. Ceramic-matrix composites (CMCs) possess low material density (i.e., only 1/4 - 1/3 of high-temperature alloy) and high-temperature resistance, which can reduce cooling air and improve structure efficiency. Understanding the failure mechanisms and internal damage evolution represents an important step to ensure reliability and safety of CMCs. This book investigates damage and fracture of fiber-reinforced ceramic-matrix composites (CMCs) subjected to stochastic loading, including: (1) tensile damage and fracture of fiber-reinforced CMCs subjected to stochastic loading; (2) fatigue hysteresis loops of fiber-reinforced CMCs subjected to stochastic loading; (3) stress rupture of fiber-reinforced CMCs with stochastic loading at intermediate temperature; (4) fatigue life prediction of fiber-reinforced CMCs subjected to stochastic overloading stress at elevated temperature; and (5) fatigue limit stress prediction of fiber-reinforced CMCs with stochastic loading. This book helps the material scientists and engineering designers to understand and master the damage and fracture of ceramic-matrix composites under stochastic loading.

Download or read book A Study of Localised Fracture Events in Continuous Fibre Reinforced Ceramic Matrix Composites written by Kevin Leslie Powell and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Environmental Durability of Fiber Reinforced Ceramic Matrix Composites written by and published by . This book was released on 1994 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this program is to investigate the environmental durability of ceramic matrix composites based on glass-ceramic and polymer pyrolysis matrices, with emphasis on the relationship between composite properties, microstructure, and chemistry, and the environment to which the composite is exposed. This environmental exposure will include the effect of oxidation, moisture, and corrosion, under conditions of high temperature and stresses. During the first year of the program, the composite system under study consisted of a barium-magnesium aluminosilicate (BMAS) glass-ceramic matrix reinforced with SiC/BN coated Nicalon SiC fibers. The results of these environmental durability tests on this composite system are discussed. Glass- ceramic matrix composites, Environmental durability of SiC/BN coated, Nicalon fiber/BMAS matrix composites, Corrosion of glass-ceramic matrix composites, Oxidation and moisture effects on glass-ceramic matrix composites.