拉、压剪作用下煤岩不等长共线裂纹相互作用

Interaction of unequal collinear cracks under tension-shear stress and compression-shear stress in coal

为研究天然煤岩体中的裂纹相互作用规律,采用Kachanov法,推导了拉剪不等长共线裂纹和单轴受压滑动闭合裂纹的应力强度因子表达式,分析了裂纹长度,裂纹间距和倾角等几何参数对共线裂纹相互作用的影响.研究结果表明:当裂纹间距增大到一条裂纹长度时,该裂纹对另一裂纹的应力强度因子几乎不产生影响;当小裂纹长度小于裂纹间距时,其对大裂纹的起裂基本无影响;当大裂纹长度大于裂纹间距时,开始影响小裂纹的起裂.

Based on the Kachanov method, the expressions for the stress intensity factors of two collinear cracks with unequal length under tension-shear and of two sliding close collinear cracks were derived in this paper. The influence of geometric parameters such as the crack length, the crack distance and the crack angle on the crack interaction were also analyzed. The results of study show that one crack will have no influence on the stress intensity factors of the other crack when the crack distance reaches the crack length; the small crack almost has no impact on the initiation of the large crack when the small crack length is shorter than the crack distance and the large crack will have influence on the small crack when the large crack length reaches the crack distance.