Localised deformation in a wide-grained sand under triaxial compression revealed by X-ray tomography and digital image correlation
Localised deformation in a wide-grained sand under triaxial compression revealed by X-ray tomography and digital image correlation
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DOI：
10.1016/j.sandf.2015.06.020
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发表时间：
2015-08
影响因子：
3.7
通讯作者：
D. Takano;N. Lenoir;J. Otani;S. Hall
中科院分区：
文献类型：
--
作者：
D. Takano;N. Lenoir;J. Otani;S. Hall
了解土的变形和破坏机理是岩土工程中的重要问题。特别是，应变局部化是土壤破坏的关键问题。在实验室力学测试中，通过对土样位移和应变的全场测量，可以有效地研究局部变形。本研究的目的是利用原位X射线（即，加载试验期间的X射线扫描）计算机断层扫描（CT）和数字图像相关（DIC）。本文关注的是内部应变的特性和应变局部化图案在宽粒砂进行三轴压缩在不同的约束压力，使用三维（3D）体积DIC。完整的三维图像的标本已被记录在几个阶段，在整个三轴试验和分析使用三维体积DIC，以获得三维增量位移和应变场。基于组合的X射线层析成像和DIC的结果，在不同的三轴压缩条件下的变形过程，特别是应变局部化的定量特征在空间和时间。
Understanding the mechanisms of deformation and failure of soils is essential in geotechnical engineering. In particular, strain localisation is a key issue for the failure of soils. In laboratory mechanical testing, localised deformation can be investigated efficiently through full-field measurements of displacement and strain in soil specimens. The objective of this study is to investigate the deformation and the failure of a soil under triaxial compression using in situ X-ray (i.e., X-ray scanning during the loading test) computed tomography (CT) and digital image correlation (DIC). This paper is concerned with the characterisation of internal strains and with strain localisation patterning in wide-grained sand undergoing triaxial compression at different confinement pressures using Three Dimensional (3D) volumetric DIC. Complete 3D images of specimens have been recorded at several stages throughout the triaxial tests and analysed using 3D volumetric DIC in order to obtain 3D incremental displacement and strain fields. Based on the results of the combined X-ray tomography and DIC, the deformation process and especially the strain localisation are quantitatively characterised in space and time under different triaxial compression conditions.