Analysis on Spatial Variability of SRM Based on Real-Time CT and the DIC Method Under Uniaxial Loading
Analysis on Spatial Variability of SRM Based on Real-Time CT and the DIC Method Under Uniaxial Loading
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DOI：
10.3389/fphy.2022.789068
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
Yanfang Wu;Xiao Li;Luqing Zhang;Jian Zhou;T. Mao;Mingtao Li
中科院分区：
文献类型：
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作者：
Yanfang Wu;Xiao Li;Luqing Zhang;Jian Zhou;T. Mao;Mingtao Li
土石混合体由高强度岩块和细颗粒土组成，严重依赖于岩石的尺寸和结构的非均匀性。由于岩块间胶结作用不均匀，粒度成分复杂，岩块分布随机，这些SRM通常会造成问题。局部化变形的研究对于工程设计、工程安全评估具有重要意义。在这项工作中，单轴压缩试验的固体火箭发动机与岩石块体的百分比为40%（质量比）下进行实时计算机断层扫描（CT）结合数字图像相关（DIC）技术。基于径向应变场和剪切场，采用半方差法定量分析了应变场和岩块运动的非均匀性。结果表明，岩块是控制剪切带几何分布的主要因素。局部化应变带通常沿土-岩界面沿着出现。根据DIC方法的实验结果，提出了描述固体火箭发动机单轴压缩损伤演化的损伤因子。该方法可用于固体火箭发动机试样变形特性的定量分析。
Soil and rock mixture (SRM) consists of high-strength rock blocks and small-grained soils, which depend seriously on the rock size and the heterogeneity of structure. Because of inhomogeneous cementation between rock blocks, complex granulometric composition, and random distribution of rock blocks, these SRMs usually cause problems. Investigation of the localized deformation is critical for successful engineering designs, engineering safety assessment. In this work, uniaxial compression testing on the SRM with a rock block percentage of 40% (mass ratio) is performed under real-time computed tomography (CT) combined with digital image correlation (DIC) technology. Based on radial strain fields and shear fields, heterogeneity of strain fields and rock block motion is analyzed quantitatively by semi-variance. The results show that rock block is the main factor controlling the shear band geometry distribution. A localization strain band usually occurs along the soil and rock interfaces. From the experimental results by the DIC method, the damage factor is presented to describe the damage evolution of the SRM under uniaxial compression. The method proposed in this study can be used to quantitatively analyze the deformation characteristics of the SRM sample.