基于含瓦斯煤受载破坏表面电位试验系统,测试研究了不同瓦斯压力下煤样受载破坏产生的电位信号变化规律及其灰色突变特征。结果表明:含瓦斯煤的破坏是载荷与瓦斯气体共同作用的结果,高压瓦斯的蚀损作用促进了煤体的破坏,引起较高的电位信号。由于当煤样受载破坏时,高压瓦斯会楔入新生裂纹,加速煤体破坏,从而产生较高的电位强度,且煤体产生的电位强度与充入的瓦斯压力成正比。笔者建立了含瓦斯煤破坏电位信号和载荷灰色-突变模型,分析了含瓦斯煤破坏的电位、载荷突变规律,发现在含瓦斯煤破坏过程中电位和载荷的灰色突变判别式可反映煤样的损伤积累、破坏临界、失稳破坏3种状态。电位信号的灰色突变特征对含瓦斯煤破坏具有明显前兆特征。
Based on the surface electric potential experimental system of coal under loaded breaking, the variation law and grey-catastrophe characteristics of electric potential signals are tested and analyzed during loaded breaking of different coal samples under different gas pressure. The result shows that the breaking of gas-bearing coal owing to the combination effect of load and gas. The erosion effect of high pressure gas promotes the breaking of coal ,which leads to higher electric potential signal. Because when coal samples under loaded breaking, the high pressure gas will wedge into the newly formed crack and accelerate the breaking of coal, thereby generates higher electric potential intensity, and the electric potential intensity has positive proportional relationship to gas pressure. The electric potential signal and grey-catastrophe model of gas-bearing coal under breaking is built, the electric potential and load catastrophe laws of gas-bearing coal under breaking are analyzed, using electric potential and grey-catastrophe discriminant of load indicating three states such as damage accumulation, failure critical and instability fracture in the process of gas-bearing coal breaking is found. There are obvious precursor characteristics in the grey-catastrophe laws of electric potential signal for gas-bearing coal under breaking.