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.
Dr. Longbiao Li is a lecturer at Nanjing University of Aeronautics and Astronautics. He received his B.E., M.E. and Ph.D. degrees from the same university in 2005, 2007 and 2011, respectively. His research focuses on fatigue, damage and fracture in high-temperature ceramic-matrix composites. Dr. Li has published 122 SCI papers and 1 monograph as first author in the past ten years. He has been involved in various projects related to structural damage, reliability and airworthiness design for aircraft and aero engine, supported by the Natural Science Foundation of China, COMAC Company and AECC Commercial Aircraft Engine Company.
Time-dependent first matrix cracking stress of ceramic-matrix composites at elevated temperatures.- Time-dependent matrix multiple cracking of ceramic-matrix composites at elevated temperatures.- Time-dependent tensile strength of ceramic-matrix composites at elevated temperatures.- Time-dependent tensile behavior of ceramic-matrix composites at elevated temperatures.- Time-dependent fatigue behavior of ceramic-matrix composites at elevated temperatures.