煤体在高压水射流作用下的损伤机制

为研究高压水射流破煤的力学机制，煤体采用J-H-C含损伤本构模型，水射流采用Bridgman状态方程，用固-流耦合算法对高压水射流冲击煤体的损伤机制进行有限元数值计算，得出了煤体在不同冲击压力水射流作用下的损伤形式，模拟与现场试验结果基本一致。研究结果表明，不同水压的水射流冲击煤体形成的损伤机制存在差别，煤体在高压水射流作用下的损伤是阶梯式，煤体在高压水射流冲击下形成压缩波和拉伸波的复合作用是形成煤体损伤的主要原因，随着破煤过程的进行，压缩区和拉伸区有进一步减小的趋势；对于不同强度煤体存在临界破煤压力和最佳破煤压力。

Damage mechanism of coal under high pressure water jetting

In order to study the mechanism of high pressure water jetting on the coal, the damage mechanism of high pressure water jetting on the coal is investigated by using numerical simulation, which is based on coal using J-H-C damage constitutive model and water jet using Bridgman equation. Based on fluid-solid coupling penalty function, a mode of numerical algorithm, the various damage forms of the coal are gained under different jetting pressures of water. The numerical calculated values are in good agreement with experimental results. The numerical simulation results show that, different water pressures of jet flow cause different damage patterns in coal. The shape of damage caused by jetting in the coal is staged and the recombination action of compression stress wave and tensile stress wave is the main factor that results in coal damage. With penetration evolving, compression zone and tensile zone reduce that are formed by high water. There is the critical breakdown pressure of water on the coal that has different fracture strength.