考虑夹杂相互作用的复合陶瓷夹杂界面的断裂分析

发布时间：2018-05-28 17:46

本文选题：圆形夹杂 + 界面裂纹　；参考：《力学学报》2016年01期

【摘要】：复合材料中夹杂含量较高时,夹杂间的相互作用能显著改变材料细观应力应变场分布,基体和夹杂中的平均应力应变水平也会发生较大变化,导致复合材料强度等力学性能发生显著变化.为修正单一夹杂模型运用在实际材料中的误差,基于相互作用直推估计法,建立一种考虑含夹杂相互作用的夹杂界面裂纹开裂模型.首先根据相互作用直推估计法,得到残余应力和外载应力共同作用下夹杂中的平均应力,再计算无限大基体中相同的夹杂达到相同应力场时的等效加载应力,将此加载应力作为含界面裂纹夹杂的等效应力边界条件,在此边界条件下求得界面裂纹尖端的应力强度因子,进而得到界面裂纹开裂的极限加载条件,并分析了夹杂弹性性能、含量、热残余应力、夹杂尺寸等因素对界面裂纹开裂条件的影响.结果表明,方法能够有效修正单夹杂模型运用在实际材料中的误差,较大的残余应力对界面裂纹开裂有重要的影响,夹杂刚度的影响并非单调且比较复杂;在残余应力较小时,降低柔性夹杂刚度或者增大刚性夹杂刚度都有利于提高材料强度;扩大夹杂尺寸将导致裂纹开裂极限应力显著降低,从而降低材料强度.
[Abstract]:When the content of inclusions in composites is high, the interaction between inclusions can significantly change the distribution of stress and strain fields, and the average stress and strain levels in matrix and inclusions will also change greatly. The mechanical properties, such as the strength of the composite material, changed significantly. In order to correct the error of single inclusion model used in practical materials, a crack cracking model of inclusion interface is established based on the direct estimation method of interaction. First, the average stress in the inclusions under the combined action of residual stress and external stress is obtained according to the interaction direct estimation method, and then the equivalent loading stress of the same inclusions in the infinite matrix is calculated when the same inclusion reaches the same stress field. The loading stress is taken as the equivalent stress boundary condition of the inclusion with interfacial crack. The stress intensity factor at the tip of the interface crack is obtained under the boundary condition, and the ultimate loading condition of the crack is obtained, and the elastic properties of the inclusion are analyzed. The effects of content, thermal residual stress and inclusion size on the cracking conditions of interfacial cracks. The results show that the method can effectively correct the error of single inclusion model used in practical materials, the larger residual stress has an important effect on the crack cracking of interface, the influence of inclusion stiffness is not monotonous and complex, and when the residual stress is small, Reducing the flexible inclusion stiffness or increasing the rigid inclusion stiffness can improve the strength of the material, and the increase of the size of the inclusion will result in a significant reduction of the crack cracking limit stress, thus reducing the strength of the material.
【作者单位】：军械工程学院火炮工程系;军械工程学院车辆与电气工程系;军械工程学院基础部;中国人民解放军78638部队;
【基金】：国家自然科学基金资助项目(11272355)
【分类号】：O346.1

【共引文献】