基于迟滞耗散能的纤维增强陶瓷基复合材料疲劳寿命预测方法  

Fatigue life prediction approach of fiber-reinforced ceramic-matrix composites based on hysteresis dissipated energy

作　　者：李龙彪[1] 

机构地区：[1]南京航空航天大学民航学院,南京210016

出　　处：《复合材料学报》2016年第4期841-851,共11页Acta Materiae Compositae Sinica

基　　金：中央高校基本科研业务费专项资金(NS2016070);江苏省自然科学青年基金(BK20140813)

摘　　要：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。Under fatigue loading of fiber-reinforced ceramic matrix composites（CMCs）,the fatigue hysteresis phenomenon appears as the fiber slipping repeatedly relative to matrix in the interface debonded region.The area of the hysteresis loops,i.e.,the hysteresis dissipated energy,can be used to monitor the damage evolution in fiber-reinforced CMCs under fatigue loading.An approach to predict the fatigue life of fiber-reinforced CMCs has been developed based on the hysteresis dissipated energy.The hysteresis loops models considering fiber failure has been developed.The relationships between the hysteresis dissipated energy,hysteresis dissipated energy-based damage parameter,stress-strain hysteresis loops and fatigue damage mechanisms,i.e.,matrix multicracking,fiber/matrix interface debonding,interface wear and fiber failure,have been established.The effects of fatigue peak stress,fatigue stress ratio and fiber volume content on the fatigue life S-N curve,hysteresis dissipated energy and hysteresis dissipated energy-based damage parameter as functions of cycle number have been investigated for fiber-reinforced CMCs.The fatigue life decreases with increasing fatigue peak stress,and increases with increasing fiber volume content;the hysteresis dissipated energy increases with increasing fatigue peak stress,and decreases with increasing stress ratio and fiber volume content;and hysteresis dissipated energy-based damage parameter decreases with increasing fiber volume content.

关 键 词：纤维增强陶瓷基复合材料 疲劳 寿命预测 迟滞回线 基体开裂 界面脱粘 纤维失效 

分 类 号：TB332[一般工业技术—材料科学与工程]