摘要
为探索实现数字图像相关法对岩土材料CT图像的分析计算,借助可进行原位单轴压缩的CT扫描实验系统,实时记录了石膏试样在不同应力水平下的CT图像,比较了采用不同相关系数、不同子区大小进行图像相关计算时的搜索匹配精度。针对子区线性小变形特点,利用最小二乘拟合得到位移场表达式,求导得到应变场,提高了应变计算的精度。分析结果反映了岩土材料内部非均匀变形的特征,揭示了单轴压缩下张拉破坏的特征。研究结果表明:采用数字图像相关法可以利用岩土材料CT图像求得其内部变形场。研究结论为提高求解效率和精度提供了参考。
The application of digital image correlation method on analysis of geomaterials CT images is proposed to obtain quantitative information of deformation and damage.By means of an in-situ uniaxial compression device integrated on an XCT system,CT images of gypsum samples under different stress were obtained.The influence of different correlation coefficients and different sub-area sizes on the search match precision is discussed.Considering the small linear deformation on sub-area,a displacement expression is obtained by using least squares fitting and derivative is used to acquire the strain expression,which improves the accuracy of strain calculation is improved.The calculation results reflect non-uniform deformation characteristics of geomaterials and reveal their tension failure mechanism under uniaxial compression.The research result has demonstrated that CT images of geomaterials can be analyzed quantitatively through digital image correlation method so as to obtain the inner deformation distribution.The specific measures discussed in this study will be helpful to further improve the efficiency and precision of calculation.
作者
杨彦从
何向
杨学峰
葛美萱
彭瑞东
YANG Yancong;HE Xiang;YANG Xuefeng;GE Meixuan;PENG Ruidong(School of Mechanical Electronic and Information Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《辽宁工程技术大学学报（自然科学版）》
CAS
北大核心
2020年第3期236-244,共9页
Journal of Liaoning Technical University (Natural Science)
基金
北京市教育委员会共建项目专项资助
中央高校基本科研业务费专项基金(2009QM03).
关键词
岩土材料
CT图像
数字图像相关法
相关系数
子区大小
位移
应变
geomaterials
CT images
digital image correlation method
correlation coefficient
sub-area size
displacement
strain
