裂纹间动态相互作用的实验观测与理论分析──以共线剪切裂纹归并为例

AN EXPERIMENTAL AND THEORETICAL INVESTIGATION OF THE DYNAMIC INTERACTION OF CRACKS SYSTEM TAKE THE COALESCENCE OF COLLINEAR SHEAR CRACKS AS AN EXAMPLE

本文以共线剪切裂纹的归并为例，研究裂纹系的动态相互作用．实验结果表明：在张破裂的意义上，小间距共线剪切裂纹的内端部实际上是阻碍结构，通过迂回弯曲的张破裂归并．本文提出一种估计张破裂扩展途径的近似方法，利用张应力破裂判据找出了潜在的破裂扩展途径的第一近似，较好地模拟了共线裂纹的破裂途径，和现有的数值模拟方法比较，可以大大缩短机时，简化计算程序，保证精确度．本研究结出了岩石剪切破裂“隧道效应”（即破裂跳过障碍体，而障碍体本身不破坏）的机理，还给出了脆性介质在摩擦、磨损过程中碎屑产生的机理．

In this paper, the coalescence of collinear shear cracks is taken as an example to study the dynamic interaction between the cracks. The experimental results shows that in the meaning of tensile fracture, the system of the inner tips of collinear shear cracks with little small gap is banter, and the inner bps have to coalescent through short tensile fracture. By using the criterion of tensile stress, An approximate method to estimate the extending path is proposed, and the extending path of singular crack and the initial extending path of the collinear cracks under pressure is imitated fairly comparing with experimental observation. Comparing with the current digital simulating,this method can shorten the computing time, simplify the program and ensure the accuracy. It is proposed that in the process of shear rupture of rock, how the fracture jump. over the barrier that doesn't failure. This process is called tunnel affection.Besides, the mechanism of the producing of the bits in the process of friction and wear is proposed.