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.

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.

This book focuses on the vibration behavior of ceramic-matrix composites (CMCs), including (1) vibration natural frequency of intact and damaged CMCs; (2) vibration damping of CMCs considering fibers debonding and fracture; (3) temperature-dependent vibration damping of CMCs; (4) time-dependent vibration damping of CMCs; and (5) cyclic-dependent vibration damping of CMCs. Ceramic-matrix composites (CMCs) possess low material density (i.e., only 1/4 or 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. Relationships between microstructure, damage mechanisms, vibration natural frequency, and vibration damping of CMCs are established. This book helps the material scientists and engineering designers to understand and master the vibration behavior of CMCs at room and elevated temperatures.

Ceramic matrix composites (CMCs) can withstand higher temperatures, reduce cooling airflow, improve turbine efficiency, and greatly reduce structural mass compared to the high temperature alloys. This book focuses on the matrix first/multiple cracking, crack opening and closure behavior in CMCs at high temperatures. While conducting in-situ experimental observations to analyze the damage mechanisms and failure modes, the author develops micromechanical damage models and constitutive models to predict the first matrix cracking stress, multiple matrix cracking density, matrix crack opening displacement, and cracking closure stress at high temperatures. The effects of composite’s constituent properties, stress level, and ambient temperature on matrix cracking, opening, and closure are also discussed. This book will help material scientists and engineering designers to understand and master the matrix cracking and closure behavior of fiber-reinforced CMCs.

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.

This book focuses on the matrix cracking behavior in ceramic-matrix composites (CMCs), including first matrix cracking behavior, matrix cracking evolution behavior, matrix crack opening and closure behavior considering temperature and oxidation. The micro-damage mechanisms are analyzed, and the micromechanical damage models are developed to characterize the cracking behavior. Experimental matrix cracking behavior of different CMCs at room and elevated temperatures is predicted. The book can help the material scientists and engineering designers to better understand the cracking behavior in CMCs.

This book focuses on mechanical hysteresis behavior in different fiber-reinforced ceramic-matrix composites (CMCs), including 1D minicomposites, 1D unidirectional, 2D cross-ply, 2D plain-woven, 2.5D woven, and 3D needle-punched composites. Ceramic-matrix composites (CMCs) are considered to be the lightweight high-temperature materials for hot-section components in aeroengines with the most potential. To improve the reliability and safety of CMC components during operation, it is necessary to conduct damage and failure mechanism analysis, and to develop models to predict this damage as well as fracture over lifetime - mechanical hysteresis is a key damage behavior in fiber-reinforced CMCs. The appearance of hysteresis is due to a composite's internal damage mechanisms and modes, such as, matrix cracking, interface debonding, and fiber failure. Micromechanical damage models and constitutive models are developed to predict mechanical hysteresis in different CMCs. Effects of a composite's constituent properties, stress level, and the damage states of the mechanical hysteresis behavior of CMCs are also discussed. This book also covers damage mechanisms, damage models and micromechanical constitutive models for the mechanical hysteresis of CMCs. This book will be a great resource for students, scholars, material scientists and engineering designers who would like to understand and master the mechanical hysteresis behavior of fiber-reinforced CMCs.

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.

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.

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.