无限介质中矩形裂纹相互作用分析

Interaction between rectangular cracks embedded in infinite medium

为评估含矩形面裂纹的无限介质的局部强度和稳定性,分析了在沿裂纹面正向和切向分布载荷作用下矩形裂纹的应力强度因子及两个共面或平行的矩形裂纹相互作用问题.基于一类不含强奇异性面力边界积分方程,采用边界单元技术给出了含裂纹介质的三维静力分析数值方法.采用该数值方法考察了应力强度因子随矩形裂纹长宽比的变化情况,以及共面和平行矩形裂纹间距对应力强度因子值的影响.结果表明,当裂纹间距减小时,共面裂纹的应力强度因子增大,而平行裂纹的主要应力强度因子则变小,表现出了不同的相互作用效应;当裂纹间距较大时,两裂纹间的相互作用效应基本消失.

The interactions between two co-planar or parallel rectangular cracks under normal and tangential loads were analyzed and the corresponding stress intensity factors （SIFs） were calculated to evaluate the local toughness and stability of an infinite medium including rectangular cracks. A numerical scheme for 3D cracked media was formulated by boundary element technique based on a kind of non-hyper-singular traction boundary integral equations. The variation of SIF with the aspect ratio of a rectangular crack and the influence of the distance between two cracks on SIF were investigated by the presented numerical method. Results showed different interaction effects for co-planar and parallel cracks. When the cracks become closer, the SIF for co-planar cracks becomes larger, while the dominant SIFs for parallel cracks become smaller. The influence of interaction tends to vanish when the distance is big enough.