Li Longbiao
College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao St., Nanjing 210016, China.
Materials (Basel). 2017 Mar 31;10(4):371. doi: 10.3390/ma10040371.
In this paper, the fatigue damage and lifetime of 2D SiC/SiC ceramic-matrix composites (CMCs) under cyclic fatigue loading at 750, 1000, 1100, 1200 and 1300 °C in air and in steam atmosphere have been investigated. The damage evolution versus applied cycles of 2D SiC/SiC composites were analyzed using fatigue hysteresis dissipated energy, fatigue hysteresis modulus, fatigue peak strain and interface shear stress. The presence of steam accelerated the damage development inside of SiC/SiC composites, which increased the increasing rate of the fatigue hysteresis dissipated energy and the fatigue peak strain, and the decreasing rate of the fatigue hysteresis modulus and the interface shear stress. The fatigue life stress-cycle (S-N) curves and fatigue limit stresses of 2D SiC/SiC composites at different temperatures in air and in steam condition have been predicted. The fatigue limit stresses approach 67%, 28%, 39% 17% and 28% tensile strength at 750, 1000, 1100, 1200 and 1300 °C in air, and 49%, 10%, 9% and 19% tensile strength at 750, 1000, 1200 and 1300 °C in steam conditions, respectively.
本文研究了二维SiC/SiC陶瓷基复合材料（CMC）在750、1000、1100、1200和1300℃的空气和蒸汽气氛中循环疲劳载荷作用下的疲劳损伤和寿命。利用疲劳滞后耗散能、疲劳滞后模量、疲劳峰值应变和界面剪切应力分析了二维SiC/SiC复合材料损伤演化与施加循环次数的关系。蒸汽的存在加速了SiC/SiC复合材料内部的损伤发展，提高了疲劳滞后耗散能和疲劳峰值应变的增加速率，以及疲劳滞后模量和界面剪切应力的降低速率。预测了二维SiC/SiC复合材料在空气和蒸汽条件下不同温度下的疲劳寿命应力-循环（S-N）曲线和疲劳极限应力。在空气中750、1000、1100、1200和1300℃时，疲劳极限应力分别接近抗拉强度的67%、28%、39%、17%和28%；在蒸汽条件下750、1000、1200和1300℃时，疲劳极限应力分别接近抗拉强度的49%、10%、9%和19%。
