Li Longbiao
College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, No. 29, Yudao St., Nanjing 210016, China.
Materials (Basel). 2016 May 27;9(6):421. doi: 10.3390/ma9060421.
In this paper, the cyclic fatigue hysteresis loops of 2D woven SiC/SiC ceramic matrix composites (CMCs) at elevated temperatures in steam have been investigated. The interface slip between fibers and the matrix existing in matrix cracking modes 3 and 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, is considered as the major reason for hysteresis loops of 2D woven CMCs. The hysteresis loops of 2D SiC/SiC composites corresponding to different peak stresses, test conditions, and loading frequencies have been predicted using the present analysis. The damage parameter, , the proportion of matrix cracking mode 3 in the entire matrix cracking modes of the composite, and the hysteresis dissipated energy increase with increasing fatigue peak stress. With increasing cycle number, the interface shear stress in the longitudinal yarns decreases, leading to transition of interface slip types of matrix cracking modes 3 and 5.
本文研究了二维编织SiC/SiC陶瓷基复合材料（CMC）在高温蒸汽环境下的循环疲劳滞后回线。基体开裂模式3和5中存在的纤维与基体之间的界面滑移被认为是二维编织CMC滞后回线的主要原因，在这两种模式下，纵向纱线中发生基体开裂和界面脱粘。利用本分析方法预测了二维SiC/SiC复合材料在不同峰值应力、试验条件和加载频率下的滞后回线。损伤参数、复合材料整个基体开裂模式中基体开裂模式3的比例以及滞后耗散能量随疲劳峰值应力的增加而增加。随着循环次数的增加，纵向纱线中的界面剪切应力降低，导致基体开裂模式3和5的界面滑移类型发生转变。
