脆性基体复合材料裂尖邻域夹杂—基体界面脱粘发展的数值模拟  

NUMERICAL SIMULATION OF EVOLUTIONARY INCLUSION MATRIX DEBONDING IN THE VICINITY OF A CRACKTIP IN A BRITTLE MATRIX COMPOSITE

作　　者：张凡[1] 牛莉莎[1] 史平安[2] 莫军[2] 

机构地区：[1]清华大学航天航空学院,北京100084 [2]中国工程物理研究院结构力学研究所,绵阳621900

出　　处：《机械强度》2007年第4期607-613,共7页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(10276020);国家重点基础研究发展计划(973)(2004CB619304)~~

摘　　要：夹杂—基体界面脱粘是脆性基体复合材料在拉伸载荷下的主要损伤机制之一。同时,材料内部裂纹尖端附近区域因应力集中,往往具有相对较高的损伤可能性。文中提出一种以一类包含"非均匀相"的解析胞元为基础的数值方法,以考察脆性基体复合材料内部裂尖临域夹杂脱粘的发展以及此过程中应力强度因子的变化。该方法分别应用含夹杂与含裂尖的解析胞元,以精确描述夹杂—基体界面与裂纹尖端附近的高梯度场函数,并利用Weibull概率函数控制加载过程中夹杂脱粘的发生。应用此方法可方便地建立复合材料内部裂尖附近细观结构的有限元模型,预测各夹杂依次发生脱粘的过程,并获得夹杂脱粘概率与裂纹场应力强度因子随载荷的发展规律。根据模拟结果,详细讨论材料各方面性质对于裂尖附近区域力学行为的影响。Inclusion-matrix interfacial debonding is one of the principal damage mechanisms in brittle matrix composites. The damage probability in the vicinity of a crack-tip is relatively higher than that in other regions of a composite due to stress concentration. A numerical approach based on a type of analytical cells each containing a micro-heterogeneity has been presented, for investigating the progressive inclusion-matrix debonding in the vicinity of a crack-tip in a brittle matrix composite, along with the evolution of stress intensity factor of the crack. Analytical cells each containing an inclusion or a crack-tip have been employed to characterize accurately the stress and displacement fields with high gradients in the vicinity of inclusion-matrix interfaces or a crack-tip. The occurrence of the debonding of a certain inclusion is controlled by means of Weibull probability function in loading process. The approach can been employed to construct the finite element model for the microstructure near a crack-tip in a composite conveniently. The course of the succes- sive debonding of inclusions from matrix can been predicted. Besides, the evolution of debonding probabilities of inclusions as well as the stress intensity factor of crack with increasing load can be obtained in simulation. According to the numerical results, the effects of various material properties on the mechanical behavior near the crack-tip have been discussed in detail.

关 键 词：夹杂-基体界面脱粘 脆性基体复合材料 损伤发展 应力强度因子 解析胞元 数值模拟 

分 类 号：TB332[一般工业技术—材料科学与工程] O343.7[理学—固体力学]