Degradation of Continuous Fiber Ceramic Matrix Composites Under Constant-Load Conditions


Book Description

Ten different ceramic matrix composite (CMC) materials were subjected to a constant load and temperature in an air environment. Tests conducted under these conditions are often referred to as stressed oxidation or creep rupture tests. The stressed oxidation tests were conducted at a temperature of 1454 deg C at stresses of 69 MPa, 172 MPa and 50% of each material's ultimate tensile strength. The ten materials included such CMCs as C/SiC, SiC/C, SiC/SiC, SiC/SiNC and C/C. The time to failure results of the stressed oxidation tests will be presented. Much of the discussion regarding material degradation under stressed oxidation conditions will focus on C/SiC composites. Thermogravimetric analysis of the oxidation of fully exposed carbon fiber (T300) and of C/SiC coupons will be presented as well as a model that predicts the oxidation patterns and kinetics of carbon fiber tows oxidizing in a nonreactive matrix.




Durability of Ceramic-Matrix Composites


Book Description

Durability of Ceramic-Matrix Composites presents the latest information on these high-temperature structural materials and their outstanding advantages over more conventional materials, including their high specific strength, high specific modulus, high temperature resistance and good thermal stability. The critical nature of the application of these advanced materials makes it necessary to have a complete understanding of their characterization. This book focuses explicitly on the durability of CMCs and will be extremely valuable for materials scientists and engineers who are dealing with the simulation of durability response and fatigue of ceramic matrix composites. - Provides the latest theoretical and applied research in the field of ceramic matrix composites, particularly as it relates to usage in aerospace propulsion systems - Presents extensive information on the micromechanics of damage evolution, lifetime prediction and durability in ceramic matrix composites - Details parameter studies that are valuable for materials development and lifetime durability studies




High-Temperature Mechanical Hysteresis in Ceramic-Matrix Composites


Book Description

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.







High Temperature Mechanical Behavior of Ceramic-Matrix Composites


Book Description

High Temperature Mechanical Behavior of Ceramic-Matrix Composites Covers the latest research on the high-temperature mechanical behavior of ceramic-matrix composites Due to their high temperature resistance, strength and rigidity, relatively light weight, and corrosion resistance, ceramic-matrix composites (CMCs) are widely used across the aerospace and energy industries. As these advanced composites of ceramics and various fibers become increasingly important in the development of new materials, understanding the high-temperature mechanical behavior and failure mechanisms of CMCs is essential to ensure the reliability and safety of practical applications. High Temperature Mechanical Behavior of Ceramic-Matrix Composites examines the behavior of CMCs at elevated temperature—outlining the latest developments in the field and presenting the results of recent research on different CMC characteristics, material properties, damage states, and temperatures. This up-to-date resource investigates the high-temperature behavior of CMCs in relation to first matrix cracking, matrix multiple cracking, tensile damage and fracture, fatigue hysteresis loops, stress-rupture, vibration damping, and more. This authoritative volume: Details the relationships between various high-temperature conditions and experiment results Features an introduction to the tensile, vibration, fatigue, and stress-rupture behavior of CMCs at elevated temperatures Investigates temperature- and time-dependent cracking stress, deformation, damage, and fracture of fiber-reinforced CMCs Includes full references and internet links to source material Written by a leading international researcher in the field, High Temperature Mechanical Behavior of Ceramic-Matrix Composites is an invaluable resource for materials scientists, surface chemists, organic chemists, aerospace engineers, and other professionals working with CMCs.




Ceramic Matrix Composites


Book Description

Ceramic Matrix Composites: Lifetime and Strength Prediction Under Static and Stochastic Loading focuses on the strain response and lifetime prediction of fiber-reinforced ceramic-matrix composites under stress-rupture loading at intermediate temperatures. Typical damage mechanisms of matrix cracking, interface debonding and oxidation, and fiber's oxidation and fracture are considered in the micromechanical analysis. Effects of composite's constituent properties, peak stress, and testing temperature on the composite's strain response and lifetime are also analyzed in detail. Finally, a comparison of constant and different stochastic stress spectrum on composite's damage evolution and fracture is discussed. This book will be a practical guide for the material researcher and component designer needing to better understand the composite's damage and fracture behavior under stress-rupture loading at intermediate temperatures. - Contains detailed analysis of the stress-rupture behavior of fiber-reinforced ceramic-matrix composites - Includes experimental data on stress-rupture behavior of different CMCs - Presents micromechanical constituent models for characterizing damage and fracture behavior under stress-rupture loading - Provides data on the physical properties of each constituent at various temperatures, along with the composite's response







Time-Dependent Mechanical Behavior of Ceramic-Matrix Composites at Elevated Temperatures


Book Description

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.




24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A, Volume 21, Issue 3


Book Description

This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.




26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A, Volume 23, Issue 3


Book Description

This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.