摘要
通过带扫描电镜的伺服实验机对岩石进行了原位拉伸观测实验,实时采集了岩石变形破坏过程中表面细观形貌的扫描电镜(SEM)照片.将亚像素插值和相关系数插值相结合,有效提升了数字散斑相关法的搜索效率和计算精度,并通过自行研发的数字散斑相关方法(DSCM)程序实现了岩石SEM图像中微小变形的分析计算.通过对比实验测定结果和软件计算结果,验证了算法的有效性.结果表明:岩石变形具有明显的非均匀性,在整体受拉的情况下局部出现受压区,其原因在于应力集中或损伤软化现象,且随着载荷的增加,损伤逐渐加剧并导致应变集中,从而诱发断裂.
A servo testing machine assembled with scanning electronic microscope was used to observe rock samples under in-situ tension conditions and the real-time SEM images of sample surface was captured during the deformation and failure process of rock samples. An algorithm was proposed by combining the interpolation of sub-pixel and the interpolation of correlation coefficient so as to improve the search efficiency and calculation accuracy. The micro deforma- tions of rocks were calculated by an own developed DSCM programming based on the SEM im- ages. The calculation results from the software were compared with the results from the exper- iments and have been validated. It was concluded that the deformation of rocks is obviously nonuniform. Although the sample is under tension conditions in the overall, compression would appear in some local zone due to stress concentration and damage softening. With the in creasing of load, damage becomes more severe and induces ultimate failure.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2012年第4期650-656,共7页
Journal of China University of Mining & Technology
基金
国家重点基础研究发展计划(973)项目(2010CB226804)
国家自然科学基金项目(10802092)
深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUE08009B)
中央高校基本科研业务费专项资金项目(2009QM03)
关键词
岩石
数字散斑相关法
扫描电镜
非均匀变形
rock
digital speckle correlation method
scanning electron microscope
nonuniform deformationp
