【作者】 满轲；

【导师】 谢和平； 周宏伟； 赵坚；

【作者基本信息】 中国矿业大学（北京） ， 工程力学， 2010， 博士

【摘要】 本文基于分离式霍普金森压杆(SHPB)试验技术,借助平台人字形切槽巴西圆盘型试件(CCNBD),详细研究了取自3个深度下同一岩性(玄武岩)的岩石动态断裂韧性的测试方法。研究发现,在满足动态力平衡的条件下,可将准静态断裂韧性计算公式推广到动态断裂韧性测试中；提出了用最小应力强度因子以及最大外载荷作为动态断裂失稳判据来判定断裂韧性的方法；运用LS-DYNA程序,分析了测试系统在满足SHPB两个基本假定(一维应力波假定和应力均匀化假定)前提下的能量耗散；在此基础上,进行了岩石动态断裂韧性测试,得到了动态断裂韧性随着加载率增大而增大的规律,并进一步应用应力场多轴化对该现象进行了解释；结合岩石的静态力学性质,讨论了影响断裂韧性的主要因素,研究发现岩石内部微裂纹的开裂、扩展、贯通主要由拉应力控制,且岩石的拉伸强度对断裂韧性起着决定性影响。更多还原

【Abstract】 Based on Split Hopkinson Pressure Bar (SHPB) testing system, and using Flattened Cracked Chevron Notched Brazilian Disc (CCNBD) specimen, this paper researches the dynamic fracture toughness test method of the same basalt with three different depths. It can extend the quasi-static fracture toughness testing equation into dynamic fracture toughness method, only if the dynamic force balance was satisfied. And it has proposed a dynamic failure criterion to determine the critical value of the stress intensity factor, i.e. the minimum dimensionless stress intensity factor and the maximum stress corresponded. The LS-DYNA program has been adopted to analyze the energy release of the testing system, and verified the two fundamental assumptions (one dimension stress wave and stress equalization). It has obtained that the dynamic fracture toughness increases with the loading rate, and illuminated it from the point of multi-axial stress field at the crack tip. It has discussed the influence factor of the fracture toughness, combined with rock static tensile strength. It provides estimation of rock failure from the micro crack growth, propagation and coalescence induced by tensile strength.更多还原