单轴压缩土样局部体积应变的均值随纵向应变的两种模式实验研究

发布时间：2018-06-28 02:30

本文选题：体积应变 + 收缩　；参考：《应用基础与工程科学学报》2017年05期

【摘要】：以单轴压缩条件下含水率为13.6%~17.2%的土样为研究对象,以双三次样条插值后采用亚像素数字图像相关方法获得的局部体积应变场为基础,通过在土样上布置尺寸及位置不同的统计窗口,研究局部体积应变的均值随纵向应变、统计窗口尺寸及位置的变化规律.发现了局部体积应变的均值与纵向应变之间关系的两种模式,即收缩模式和收缩-膨胀模式.对于收缩-膨胀模式,着重研究了统计窗口的最小体积对应的纵向应变.从局部体积应变场的分布特点出发,解释了最小体积对应的纵向应变随统计窗口尺寸及位置的变化规律.随着统计窗口尺寸的增加,最小体积对应的纵向应变有增加的趋势,或者保持不变.最小体积对应的纵向应变增加应与局部体积应变高值区的分布较为集中或尺寸较小有关;最小体积对应的纵向应变保持不变应与局部体积应变高值区的分布较为分散或剪切带较为密集有关.在纵向应变增加的过程中,局部体积应变的均值与统计窗口尺寸之间的关系由相对平直向相对不平直转变,对最小体积对应的纵向应变之后上述关系的3种模式的原因进行了解释.
[Abstract]:Taking the soil sample with water content of 13.6g% under uniaxial compression as the research object, based on the local volume strain field obtained by using sub-pixel digital image correlation method after bicubic spline interpolation. The variation of the mean value of local volume strain with longitudinal strain, size and position of statistical window is studied by arranging statistical windows with different sizes and positions on soil samples. Two models of the relationship between the mean value of local volume strain and the longitudinal strain are found, that is, the contraction mode and the shrinkage expansion model. For the contraction-expansion model, the longitudinal strain corresponding to the minimum volume of the statistical window is studied. Based on the distribution characteristics of the local volume strain field, the variation of the longitudinal strain corresponding to the minimum volume with the size and position of the statistical window is explained. With the increase of the size of the statistical window, the longitudinal strain corresponding to the minimum volume increases or remains unchanged. The increase of the longitudinal strain corresponding to the minimum volume should be related to the distribution of the high value region of the local volume strain or the smaller size. The invariance of the longitudinal strain corresponding to the minimum volume should be related to the distribution of the high value region of the local volume strain or the density of the shear band. In the process of longitudinal strain increasing, the relationship between the mean value of local volume strain and the size of statistical window changes from relative flatness to relative irregularity. The reasons for the above three models after the longitudinal strain corresponding to the minimum volume are explained.
【作者单位】：辽宁工程技术大学计算力学研究所;辽宁工程技术大学力学与工程学院;
【基金】：国家自然科学基金项目(51574144) 辽宁省高等学校优秀人才支持计划(LR2015029) 辽宁省科学事业公益研究基金项目(2014003008) 高等学校博士点专项科研基金项目(20132121110006)
【分类号】：TU43

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