Data for: Mechanisms of root-reinforcement in soils: an experimental methodology using four-dimensional X-ray computed tomography and digital volume correlation

Collection of data files used in the paper titled: Mechanisms of root-reinforcement in soils: an experimental methodology using four-dimensional X-ray computed tomography and digital volume correlation. Additional dataset which covers the noise study CT scans and digital volume correlation noise studies can be found in DOI: 10.5281/zenodo.3361832 <strong>Data contains the following:</strong> X-ray CT data for the interrupted direct shear tests of a soil sample containing a Willow plant. The first file is the specimen scanned unloaded, followed by seven incremental shear load steps to 20 mm shear displacement. Files are 8-bit unsigned and 1800x1800x1600px. Voxel resolution is 0.04642 mm. <strong>20180430_HUTCH_1839_DJB_willow_C_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_A_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_B_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_C_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_D_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_E_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_F_8-bit_1800x1800x1600.raw</strong> <strong>20180430_HUTCH_1839_DJB_willow_C_Load_G_8-bit_1800x1800x1600.raw</strong> Direct shear vs. displacement data is presented in an Excel spreadsheet: <strong>All_load_data_with_reducing_area.xlsx</strong> Normal and shear strain DVC data which has been averaged and plotted against specimen depth is presented in an Excel spreadsheet: <strong>Average_slice_vs_depth_data_all_samples_all_loads3.xlsx</strong> CT scan metadata giving information to the scan settings, voxel resolution, etc. is contained in a .zip file which consists of .xtekct and .XML files generated from the Nikon CT scanner. <strong>CT_Scan_Metadata.zip</strong> Drawings and Solidworks CAD files of the direct shear test rig are contained within the .zip file. There are a number of parts to the assembly. The file SSSB1003-5.SLDASM contains the complete assembly of the direct shear rig and will help identify the part names. The folder CAD_Drawings contains pdf documents of the part drawings. <strong>Direct_Shear_Drawings_Solidworks_Files.zip</strong> Tabulated DVC data taken at 32x32x32px subset size is contained inside a .zip file. These consist of tab separated .dat files from unloaded (data_1.dat) through incremental load steps Load A, Load B... Load G, (data_2.dat, data_3.dat... data_8.dat). The structure of the .dat file contains columns of data with each column number corresponding to the following: (1) x, (2) y (3) z, (4) vx, (5) vy, (6) vz, (7) exx, (8) eyy, (9) ezz, (10) exy, (11) exz, (12) eyz, (13) volumetric strain, (14) is valid. Columns 1-3 are subset positions in mm, 4-6 are displacements in mm, 7-9 are normal strains, 10-12 are shear strains, 13 is volumetric strain and 14 is a binary value indicating if the subset is valid. <strong>DVC_Load_Data_Willow_C.zip</strong> Tabulated DVC data applied to the load step CT data at 32, 48, 64, 96, 128 pixels is presented in the .zip files containing .dat tab separated files. The structure of the .dat files is described in the previous bullet point. These files were used to construct the noise study applied to incrementally loaded CT data by sampling regions away from the shear zone where the strain signals are close to zero. <strong>DVC_Noise_Study_Data_Load_Steps_Willow_C.zip</strong> Processed noise study data which compares the effects of DVC subset size is presented in the .xlsx file. This file contains both the controlled noise experiment data (stationary, magnification and rigid body motion) and noise study data applied to incrementally loaded data using sampled regions away from the shear zone where the strain signals are close to zero. <strong>Willow_C_Processed_Noise_study2.xlsx</strong> Tabulated data which compares the local x displacement vs depth profile from DVC and direct measurement of root position is contained in the following Excel spreadsheet file: <strong>X_Displacement_Root_and_DVC_Comparison_Willow C.xlsx</strong>本数据集为论文《土壤中根系加固机制：基于四维X射线计算机断层扫描与数字体相关（Digital Volume Correlation, DVC）的实验方法》所使用的数据文件集合。另有涵盖噪声研究CT扫描与数字体相关噪声研究的附加数据集，可在DOI: 10.5281/zenodo.3361832获取。 **数据集包含以下内容：** 含柳树植株的土样间断直剪试验的X射线CT数据。首个文件为卸载状态下扫描的试样，后续依次为7级逐级施加的剪切荷载直至20mm剪切位移的扫描数据。所有文件均为8位无符号格式，分辨率为1800×1800×1600像素，体素分辨率为0.04642 mm。对应的文件包括： **20180430_HUTCH_1839_DJB_willow_C_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_A_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_B_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_C_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_D_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_E_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_F_8-bit_1800x1800x1600.raw** **20180430_HUTCH_1839_DJB_willow_C_Load_G_8-bit_1800x1800x1600.raw** 直剪荷载与位移数据以Excel表格形式存储，文件名为：**All_load_data_with_reducing_area.xlsx**。 经平均处理并以试样深度为横轴绘制的法向与剪切应变DVC数据以Excel表格形式存储，文件名为：**Average_slice_vs_depth_data_all_samples_all_loads3.xlsx**。 CT扫描元数据（包含扫描参数、体素分辨率等信息）存储于由Nikon CT扫描仪生成的.xtekct与.xml格式文件组成的压缩包中，文件名为：**CT_Scan_Metadata.zip**。 直剪试验台的工程图与Solidworks CAD文件存储于该压缩包中。该装配体包含多个零部件，其中SSSB1003-5.SLDASM文件包含直剪试验台的完整装配结构，可用于识别各零部件名称。CAD_Drawings文件夹内包含各零部件工程图的PDF文档，压缩包文件名为：**Direct_Shear_Drawings_Solidworks_Files.zip**。 采用32×32×32像素子集尺寸的DVC制表数据存储于压缩包中，该压缩包包含以制表符分隔的.dat格式文件，覆盖卸载状态（data_1.dat）及逐级加载步骤Load A至Load G（对应data_2.dat至data_8.dat）。.dat文件的列结构如下：第1列为x坐标，第2列为y坐标，第3列为z坐标，第4至6列为位移（单位：mm），第7至9列为法向应变，第10至12列为剪切应变，第13列为体积应变，第14列为二进制有效性标记（用于指示该子集是否有效）。该压缩包文件名为：**DVC_Load_Data_Willow_C.zip**。 针对荷载步CT数据、采用32、48、64、96、128像素子集尺寸的制表DVC数据存储于包含制表符分隔.dat文件的压缩包中，.dat文件的列结构与前文所述一致。此类文件用于开展针对逐级加载CT数据的噪声研究，研究中选取剪切带外应变信号接近零的区域进行采样分析。该压缩包文件名为：**DVC_Noise_Study_Data_Load_Steps_Willow_C.zip**。 用于对比DVC子集尺寸影响的经处理噪声研究数据存储于Excel表格中，该文件同时包含受控噪声试验数据（静止、放大与刚体运动工况）以及针对逐级加载数据、选取剪切带外低应变区域开展的噪声研究数据。文件名为：**Willow_C_Processed_Noise_study2.xlsx**。 对比DVC得到的局部x位移沿深度分布与根系位置直接测量结果的制表数据存储于以下Excel表格中：**X_Displacement_Root_and_DVC_Comparison_Willow C.xlsx**。