摘要
在PFC2D平台下设计了均质、含0.2 mm矿物颗粒和含0.2 mm孔隙砂岩的数值巴西圆盘试验。在试件左、右、中间、上部和下部设定了5个半径为5 mm的分析球。分别分析了试件加载过程中的x、y方向应力值。分析发现矿物颗粒的存在极大地增强了砂岩的力学行为,内部分析点x方向应力均高出其他情况x方向应力1～2个数量级,y方向应力则在同一个数量级上增加1～2倍。孔隙的存在弱化了砂岩力学行为,x、y方向应力均在同一数量级上减小1～2倍。说明外部监测到的应力变化与材料内部应力的变化情况有很大差异,这是物质约束与边界约束的不同造成的。
Three Brazilian disc numerical simulation samples of sandstone were established by PFC2D,they are homogeneous sample,samples containing dia.0.2 mm mineral grains and dia.0.2 mm pore.The 5 analytical circular areas with radius of 5 mm each are set up at the left,right,middle,upper and bottom of the test specimens,and the stress values at the x and y directions are analyzed in the loading process respectively.The analytical results indicate that the existence of mineral grains can greatly enhance the mechanical behaviors of sandstones.The stress in x direction at the inner analytical point is 10~100 times higher than the stress in x direction of other cases,and the stress in y direction increases 1~2 times as much as that in the same order of magnitude.The pore existence can weaken the mechanical behavior of sandstone,and the stresses in x and y directions in the same order of magnitude will decrease by 1~2 times as much.All these indicate that the stress changing monitored externally differs greatly from the internal stress changing in a material.This phenomenon is caused by the differences of material constraints and boundary constraints.
出处
《西安理工大学学报》
CAS
北大核心
2012年第1期72-77,共6页
Journal of Xi'an University of Technology
基金
国家自然科学基金资助项目(50879069)
水利部公益性行业科研专项基金资助项目(201201053-03)
陕西省黄土力学与工程重点实验室重点科研计划基金资助项目(09JS103)
关键词
颗粒流
砂岩
矿物颗粒
孔隙
应力
particle flow
sandstone
mineral particle
pore
stress
