A spherical harmonic-random field coupled method for efficient reconstruction of CT-image based 3D aggregates with controllable multiscale morphology
A spherical harmonic-random field coupled method for efficient reconstruction of CT-image based 3D aggregates with controllable multiscale morphology
复制标题
DOI：
10.1016/j.cma.2023.115901
复制
发表时间：
2023-03
影响因子：
7.2
通讯作者：
Fuxin Guo;Hui Zhang;Zhen-Jun Yang;Yu-jie Huang;P. Withers
中科院分区：
文献类型：
--
作者：
Fuxin Guo;Hui Zhang;Zhen-Jun Yang;Yu-jie Huang;P. Withers
混凝土的物理力学性能与集料的宏观形态、中尺度的局部圆度和细尺度的表面纹理等密切相关。本研究开发了一种使用微X射线计算机断层扫描（μ XCT）图像、球谐函数（SH）分析和随机场重建算法高效生成真实3D聚集体的计算方法。该方法首先对CT图像分割得到的真实的骨料表面进行SH函数分解并映射到不同尺度的半径场，然后提取其统计数据，通过谱表示方法和折叠算法重建新骨料。通过比较真实的骨料和新骨料的四个形态指标（球度、凸度、圆度和粗糙度），验证了该方法的有效性，并证明了该方法在特定尺度下重构具有特定形态指标的新骨料时的灵活性。作为一个应用程序，八套富勒级随机骨料与目标形态指标的构建和包装成立方体容器，以产生数字混凝土试样。骨料的球度和凸度与最大骨料体积分数呈线性相关。所开发的方法也可以应用于其他颗粒材料，如药物颗粒，胶体，陶瓷，土壤和煤。
The physical and mechanical performance of concrete is inherently dependent on aggregate morphology including the general shape at coarse-scale, the local roundness at medium-scale and the surface texture at fine-scale. This study develops a computational method for highly efficient generation of realistic 3D aggregates using micro X-ray Computed Tomography (μ XCT) images, the spherical harmonic (SH) analysis and a random-field reconstruction algorithm. In this method, the real aggregate surface segmented from CT images is first decomposed and mapped by the SH function to radius fields at different scales, whose statistical data are then extracted to reconstruct new aggregates through a spectral representation method and an innovative folding algorithm. The proposed method is verified by comparison of four morphology indices (sphericity, convexity, roundness and roughness) of the real aggregate and the new ones, and its flexibility in reconstructing new sets of random aggregates with specified morphology indices at selected scales is also demonstrated. As an application, eight sets of Fuller-grade random aggregates with target morphology indices are constructed and packed into a cube container to generate digital concrete specimens. The aggregate sphericity and convexity are found to be linearly correlated with the maximum aggregate volume fraction that can be packed into the cube. The developed method can be also applied to other granular materials, such as pharmaceutical particles, colloids, ceramics, soils and coal.