摘要
采用双面剪切模型实验方法,对一种花岗岩试件进行岩石摩擦滑动实验研究。以CCD相机构建实验图像数据采集系统,利用数字散斑相关方法对岩石试件在摩擦滑动过程中的位移场、滑动面的滑动位移及变形能密度的演化特征进行研究。研究结果表明:(1)剪应力初始缓慢增长阶段,滑动岩块位移场空间非均匀分布是由试件自身随机缺陷和滑动接触面上随机分布的凹凸体的变形引起,位移主要为试件的弹性变形位移;剪应力线性增长阶段,试件局部区域处于滑动状态,试件位移场的空间分布受滑动面主导,试件整体位移场体现出较规则分布特点;剪应力非线性增长阶段,试件位移场空间演化上,滑动面分布有强段和弱段,滑动面弱段位移场等值线呈均匀分布,等值线近似直线且相互平行,滑动面强段的位移场等值线呈非均匀分布,位移场等值线呈曲线状;试件位移场时间演化上,强段和弱段区域随载荷增长呈动态变化。(2)影响滑动面强段分布的因素为凹凸体的阻碍性,凹凸体的阻碍性不仅与其自身强度有关,还与所在区域滑动面间的咬合程度有关;滑动面水平位移演化受滑动面强段摩擦滑动状态控制,水平位移曲线与加载曲线有较好的对应关系。(3)在剪应力非线性增长阶段,滑动面强段处于静摩擦和滑动的交替状态,滑动面滑动速度表现出突变现象,变形能密度在此阶段发生积累与释放的波动式演化特征。
The double-sided shear model experiment was applied to study the friction and sliding of granite specimens. The experimental image gathering system was constructed with CCD camera. Meanwhile,by using the digital speckle correlation method,the evolution characteristics of the displacement field,sliding displacement on the sliding surface and deformation energy density of specimens during friction and sliding were studied. The results of the study show that：in the initial slow growth phase of shear stress,the non-uniform spatial distribution of displacement field in the sliding rock is caused by the random defects in the specimen and the deformation of the concave and convex body randomly distributed on the sliding surface. The displacement is mainly the elastic deformation of specimen. In the linear growth phase of shear stress,a certain part of the specimen is in sliding state. The spatial distribution of the displacement field is dominated by sliding surface, and the whole displacement field of the specimen shows a characteristic of regular distribution. In the nonlinear growth phase of shear stress,the sliding surface has strong and weak sections spatially. The displacement contour lines of the weak section on the sliding surface display uniformly,approximately in straight and parallel. While in the strong section on the sliding surface,the displacement contour lines are non-uniformly distributed curves. The strong and weak sections change with loading process. The factor affecting the distribution of the strong section on the sliding surface is the hindrance of the concave and convex bodies. The hindrance of the concave and convex body is not only related to its own strength,but also related to the degree of occlusion on the sliding surfaces in this area. The horizontal displacement is controlled by the sliding condition of the strong section on the sliding surface. The horizontal displacement curve has a good correspondence with the loading curve. In the nonlinear growth phase of shear stress,static friction and sliding appear alternately on the strong section of sliding surface. The sliding velocity on the sliding surface varies drastically. Meanwhile,the deformation energy density begins to accumulate and release in this phase.
作者
宋义敏
张悦
许海亮
李肖飞
王亚飞
SONG Yimin;ZHANG Yue;XU Hailiang;LI Xiaofei;WANG Yafei(School of Civil Engineering,North China University of Technology,Beijing 100144,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第8期1777-1784,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51474013)~~
关键词
岩石力学
摩擦滑动
位移场
变形能密度
滑动成核
数字散斑相关方法
rock mechanics
friction and sliding
displacement field
deformation energy density
sliding nucleation
digital speckle correlation method
