摘要
为了分析岩石在冲击载荷下的动态劈裂破坏情况,通过分析巴西圆盘在动态劈裂和静态劈裂时表面应力分布均匀化的相似性,可以将静态劈裂时的弹性理论应用到动态劈裂当中,得到巴西圆盘在动态劈裂下的动态抗拉强度、动态抗压强度、应变率和应变的计算公式。应用三维非线性动力学分析软件ANSYS/LS-DYNA,模拟巴西圆盘在分离式霍布金逊压杆实验装置上受冲击时动态劈裂的整个实验过程。基于动态抗拉强度公式和动态抗压强度公式,对试件的实际拉应力曲线与计算拉应力曲线进行对比,以及对实际压应力曲线与计算压应力曲线进行对比,通过对比曲线的相互吻合性证明数值模型适用于对岩石冲击劈裂破坏性质的研究。通过分析试样表面的应力均匀化过程以及试样表面对心压缩轴线上拉应力方向的应力分布情况,得出试样在对心压缩轴线表面上的破坏顺序是由从两个冲击端部向中心发展的;通过分析试样沿对心压缩轴线所切剖面上的拉应力分布,得出试样在厚度方向上的破坏顺序是由表面向内部发展的。
In order to analyze the dynamic splitting failure of rock,analyze the similarity of Brazil disk surface uniform distribution about dynamic splitting and static splitting,apply elasticity theory of static splitting about the Brazilian disc to the dynamic splitting,the formula of dynamic tensile strength,dynamic compressive strength,strain rate and strain about Brazil disk under dynamic splitting could be obtained.Use the application of three-dimensional nonlinear dynamics analysis software ANSYS/LS_DYNA to simulate the entire dynamic splitting experiment on separate Hopkinson device.Based on dynamic tensile strength formula and dynamic compressive strength formula,contrast the actual tensile stress curve and the calculate tensile stress curve and contrast the actual compressive stress curve and the calculate compressive stress curve,the mutual agreement of curves proved that the numerical model suitable for the study of the properties of rock impact splitting failure.The process of stress uniformity about the specimen surface and the stress distribution along the direction about tensile stress on the axis of heart compression have been analyzed to get the destructive sequence was from two impact end toward the center;the tensile stress distribution on cardiac along the axis of heart compression have been analyzed to get the destructive sequence was from surface to inside.
出处
《西安科技大学学报》
CAS
2013年第3期283-290,共8页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(51174005/51074005/51134012)
霍英东青年教师基金基础性研究课题(121050)
中国矿业大学煤炭资源与安全开采国家重点实验室开放研究基金资助项目(10KF03)
关键词
岩石动力学
动态劈裂
数值模拟
应力均匀性
应力分布
rock dynamics
dynamic split
numerical simulation
stress uniformity
stress distribution
