基于多尺度内聚颗粒模型的挤压分级破碎研究

Research on extrusion rushing based on multi-scale cohesive particle model

为分析岩石在挤压破碎下的微观受力与裂纹萌生、扩展情况,通过定义单元体不同尺度特性和单元体之间黏结键不同强度特性构建了多尺度内聚颗粒模型,并基于EDEM软件进行颗粒模型挤压破碎数值模拟;以颗粒模型内部黏结键的断裂与受力情况,模拟、分析多裂纹的萌生与扩展,从而揭示岩石破碎的微观作用机制。最后分析咬入速度对模型破碎的影响,结果表明:咬入速度对颗粒模型的破碎影响仅体现在作用时间上,而对模型的断裂状态和断裂形式未有影响;所构建的多尺度内聚力颗粒模型能够较好地体现分级破碎的特点。

In order to analyze the micro-stress situation and crack initiation and propagation of rock under extrusion and crushing,the numerical simulation of extrusion and crushing of particle model which is established by defining different scale characteristics of the unit body and different strength characteristics of bond between the unit bodies is conducted based on the EDEM software. The initiation and growth of multiple cracks is simulated and analyzed according to bond fracture and stress situation inside the particle model,which could reveal the microscopic mechanism of crushing of rock. At last,the influence of bite rate on the crushing of the model is analyzed,The results show that the influence of the biting velocity on the crushing of the particle model is only on the action time,but not on the fracture state and the fracture form of the model and the multi-scale cohesive particle model constructed could well reflect the characteristics of grading broken.