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纤维增强陶瓷基复合材料(CMCs)在疲劳载荷作用下,纤维相对基体在界面脱粘区往复滑移导致其出现疲劳迟滞现象,迟滞回线包围的面积,即迟滞耗散能,可用于监测纤维增强CMCs疲劳损伤演化过程。提出了一种基于迟滞耗散能的纤维增强CMCs疲劳寿命预测方法及考虑纤维失效的迟滞回线模型,建立了迟滞耗散能、基于迟滞耗散能的损伤参数、应力-应变迟滞回线与疲劳损伤机制(多基体开裂、纤维/基体界面脱粘、界面磨损与纤维失效)之间的关系。分析了疲劳峰值应力、疲劳应力比与纤维体积分数对纤维增强CMCs疲劳寿命S-N曲线、迟滞耗散能和基于迟滞耗散能的损伤参数随循环次数变化的影响。疲劳寿命随疲劳峰值应力增加而减小,随纤维体积含量增加而增加;迟滞耗散能随疲劳峰值应力增加而增加,随应力比和纤维体积分数增加而减小;基于迟滞耗散能的损伤参数随纤维体积分数增加而减小。
Fiber reinforced ceramic matrix composites (CMCs) under fatigue loading, the fiber relative to the substrate in the interfacial debonding zone reciprocating slippage caused fatigue phenomenon, hysteresis loop surrounded by the area, that hysteresis dissipation energy, can be used to monitor the fiber Enhance the fatigue damage evolution of CMCs. A new method for predicting the fatigue life of fiber-reinforced CMCs based on hysteretic energy dissipation and a hysteresis loop model considering fiber failure were proposed. The hysteresis dissipation energy, damage parameters based on hysteresis dissipation energy, stress-strain hysteresis loop and The relationship between fatigue damage mechanisms (multi-matrix cracking, fiber / matrix interface debonding, interface wear and fiber failure). The effects of fatigue peak stress, fatigue stress ratio and fiber volume fraction on the fatigue life S-N curves, hysteretic energy dissipation and hysteresis dissipation energy-dependent damage parameters of fiber-reinforced CMCs with cyclic changes were analyzed. The fatigue life decreases with the increase of fatigue peak stress and increases with the increase of fiber volume. The hysteresis dissipation energy increases with the increase of fatigue peak stress and decreases with the increase of stress ratio and fiber volume fraction. Parameters decrease with increasing fiber volume fraction.