基于多尺度内聚颗粒模型的轴压破碎过程研究

Visualization of the Crushing Process of Multi-scale Cohesive Rock Particle Model

针对岩石内部的非规则特性,利用高倍显微镜观察分析岩石内部的几何特征,构建岩石的分级颗粒模型,并结合离散元思想确定各级颗粒之间的力学关系;采用离散元软件EDEM,对柱状岩石的分级颗粒模型进行轴压破碎试验模拟,从宏观和细观角度分析岩石的破碎过程。模拟结果与轴压破碎试验进行对比,得出:岩石内部存在部分聚集现象,粘结键强度决定颗粒承载力,所构建的岩石内部特征多尺度内聚颗粒模型可以很好地描述岩石动态破碎过程中微裂纹的生成与扩展,实现了岩石破碎过程可视化。

Aimed at the irregular characteristics of the rock,the geometric features of the rock were analyzed with a high-power microscope.A graded particle model of rock was constructed,and the mechanical relationship among particles at various levels was determined through combining the discrete element theory.By using discrete element software EDEM,the axial compression crushing experiments were conducted on the graded particle model of cylindrical rock,and the rock crushing process was analyzed from macroscopic and mesoscopic perspectives.Comparing the results of the laboratory tests with those of the numerical simulation,it can be concluded that there was a partial aggregation phenomenon inside the rock,and the adhesive bond strength determined the bearing capacity of the particles.The multi-scale cohesive particle model of rock internal characteristics can well describe the formation and development of micro-cracks in the dynamic rock breaking process,which realized the visualization of rock breaking process.