中文摘要：

为研究动载侵入岩石过程中的裂纹演化规律和预测裂纹长度,根据牛顿第二定律及波动理论,建立了岩石在冲击过程中的最大冲击力与冲击速度间的数学模型,结合岩石在静载作用下的载荷与裂纹长度间的关系,建立了岩石在冲击载荷作用下形成裂纹的长度预测模型,并利用离散元数值模拟方法研究了岩石动态破碎过程中裂纹的形成与扩展特征以及冲击速度对裂纹长度的影响规律。分析研究发现,岩石在冲击力作用下形成的裂纹以张性裂纹为主,且径向裂纹向着岩石自由表面扩展,侧向裂纹从损伤区萌生并向岩石内部逐渐扩展;径向裂纹长度和侧向裂纹长度均与冲击速度呈幂函数关系,数值模拟结果与理论模型结果基本吻合;冲击速度由15m/s增大至35m/s,岩石的破碎范围和破碎深度逐渐增大,形成的径向裂纹长度从3.47mm增大到9.03mm,侧向裂纹长度从7.29mm增大到14.58mm。研究结果为研究岩石的动载侵入断裂和动态破碎机理提供了理论依据。

英文摘要：

In order to study the rock fracture and fissure propagation and evolution rule and to predict fissure（crack）length in the process of dynamic load intruding the rock,a mathematical model for describing relationship between the maximum impact force and the impact velocity during rock breaking was developed according to the Newton＇s second law and the wave theory.Based on the relationship between static load and crack length of rock,the theoretical model of fissure length under impact load was established.In addition,researchers used a discrete element numerical simulation method to investigate the characteristics of fissure formation and propagation and the influence of impact velocity on crack length.The results indicate that tensile fissures are mainly formed under the impact force,and the radial cracks extend to rock free face,lateral fissures initiate from the damaged area and then extend to the inside of rock.Radial and lateral fissure lengths have a power function relationship with the impact velocity,and the numerical simulation results are consistent with the results of theoretical model.As the impact velocity increases from15m/s to 35m/s,the rock breaking range and depth increase gradually,the radial crack length increased from 3.47 mm to 9.03 mm and lateral crack length increased from 7.29 mm to 14.58 mm.The research results can provide a theoretical reference for investigating rock fractures and fissure propagation under dynamic load intrusion and dynamic crushing mechanism.