含固有缺陷复合材料有效弹性性能预报  

Effective Elastic Property Prediction of Ceramic Composite with Inherent Defect

作　　者：付云伟[1] 刘协权[1] 倪新华[1] 李宝峰[1] 

机构地区：[1]军械工程学院基础部,石家庄050003

出　　处：《机械工程学报》2012年第16期46-51,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(10872216)

摘　　要：根据缺陷在复合陶瓷中分布特点,将缺陷简化为刚度为0的椭球夹杂,嵌入到横观各向同性基体中,建立含缺陷复合材料的细观结构模型。应用相互作用直推估计法推导含缺陷胞元的有效刚度,结合刚度体平均化方法,假设胞元空间随机分布,得到复合材料的等效刚度表达式,分析横观各向同性基体中缺陷体积分数、取向和形状对材料等效刚度的影响,并进一步讨论缺陷周围基体各向异性的影响。结果表明,缺陷存在导致材料弹性性能明显降低,在缺陷体积分数较小时,弹性常数对缺陷体积分数更加敏感;缺陷形状对弹性常数有较大影响,当缺陷接近于薄片状时,缺陷厚度对弹性常数影响明显,而缺陷平面形状对弹性常数基本没有影响;当片状缺陷垂直于基体中弹性模量较大的轴时,缺陷对材料有效性能的降低作用更显著,考虑缺陷周围基体各向异性是很有必要的。According to the distribution feature of inherent defect in ceramic composite, defect is simplified as non-stiffness ellipsoidal inclusion in transverse isotropic matrix, and relevant microstructure model is established. Cell＇s equivalent stiffness is calculated based on improved interact direct derivative （IDD） estimate, assuming cells distributed randomly in ceramic, the equivalent stiffness of rod ceramic composite is obtained with the help of volume averaging approach, and the effect of inherent defect in transverse isotropic matrix is analyzed, and the effect of anisotropic property of matrix discussed either. Result indicate that effective elastic constants is reduced obviously by inherent defect and it is sensitive to defect fraction as the fraction is low; shape of defect has important influence to effective elastic constants; for a lamellar defect, thick of defect has significant influence especially while width has little influence; and the weaken effect is more obviously as the defect plane perpendicular to elastic axis of greater modulus, it is necessary to take anisotropic property of matrix into consideration.

关 键 词：固有缺陷 等效刚度 相互作用直推估计 横观各向同性 

分 类 号：O346[理学—固体力学]