论文部分内容阅读
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.
Taking soil samples with moisture content of 13.6% -17.2% under uniaxial compression as the research object, based on the local volumetric strain field obtained by bi-cubic spline interpolation after using sub-pixel digital image correlation method, Size and location of the statistical window, the study of the local volume and strain of the mean with the vertical strain, the size of the statistical window and the position of the variation.We found the relationship between the local volume strain and the longitudinal strain of the two modes, namely contraction mode and contraction For the contraction-expansion mode, the longitudinal strain corresponding to the minimum volume of the statistical window is emphatically studied. From the distribution characteristics of the local volumetric 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 has an increasing tendency or remains unchanged, and the increase of the longitudinal strain corresponding to the minimum volume should be related to the more concentrated or smaller size distribution of the high volume of local volumetric strain. Vertical strain corresponding to the minimum volume should remain unchanged and the distribution of the high volume of localized volume strain should be more dispersed or shear With the more intensive.When the longitudinal strain increases, the relationship between the mean value of the local volumetric strain and the size of the statistical window changes from relatively straight to relatively uneven straightness, and after the longitudinal strain corresponding to the minimum volume, The reason for the mode has been explained.