摘要
为研究数字体图像相关法(Digital volume correlation,DVC)测量孔隙类岩石内部三维变形场的可行性,利用X射线CT扫描获取孔隙岩石(中砂岩,红砂岩和油砂岩)的数字体图像,采用虚加变形的数字实验方法得到变形体图像,由DVC法得出测量值并进行比较分析.研究表明:孔隙类岩石内部结构可以作为散斑结构,应用DVC法计算内部变形,不同的结构特征,影响着DVC法的精度与准确度;油砂岩内部结构作为散斑结构时,具有较高的精度,其次是红砂岩,中砂岩;给出了评价三维散斑结构的指标-平均灰度梯度,平均灰度梯度值越大,相应的以该散斑结构进行DVC法计算时,所得精度与准确度也高;采用数字实验的分析孔隙岩石内部结构对DVC法计算精度的影响是一种简单易行的方法,其结果有助于实验方案的制定.
In order to evaluate the possibility of measuring internal three dimensional displacement fields by using Digital Volume Correlation（DVC）, the digital experiment in which the artificial deformation is imposed on the images is carried out on the digital volume images of porous rocks, such as medium sandstone, red sandstone, and reservoir sandstone, which are obtained by X-ray Computer Tomography. The results indicate that the internal features of the porous rock can be used as speckle patterns, and the accuracy and the precision of DVC are affected by the speckle features. The performance of DVC is the best based on speckle patterns in the reservoir sandstone, the red sandstone is the second, and the medium sandstone is the last. The Mean Intensity Gradient, a three dimensional speckle pattern evaluation parameter, is proposed. The bigger Mean Intensity Gradient, the higher accuracy DVC. Digital experiment is an easy method to analyze the influence of porous rock internal structure on DVC, and the results will be benefit to make the experimental schemes.
出处
《辽宁工程技术大学学报（自然科学版）》
CAS
北大核心
2014年第8期1080-1085,共6页
Journal of Liaoning Technical University (Natural Science)
基金
国家重点基础研究发展计划基金资助项目(2010CB732002)
国家自然科学基金资助项目(51374211)
中央高校基本科研业务费专项资金资助项目(2009QM02)
关键词
孔隙岩石
内部三维变形场
数字体图像相关法
工业CT
数字实验
porous rock
internal three dimensional displacement
digital volume image
industrial computer tomography
digital experiment
