The modelling of rock structure is of great significance in characterizing rock characteristics and studying the failure laws of rock samples. In order to construct a high‐fidelity model of the rock structure efficiently, this paper proposes an adaptive mesh dissection algorithm based on the Voronoi structure. Image processing techniques, including greyscale, threshold segmentation and edge detection, are applied to simplify the original rock image into a feature edge image. Then, a probability density diagram of the feature image is generated, which provides a probabilistic basis for the subsequent spreading of mesh seed points. Moreover, the concept of polygonal representation rate and the mesh quality evaluation system of four‐dimensional metrics are established to suggest values for the seed point parameters of the initial mesh. The initial mesh is continuously optimized and iterated by barycentric iteration and gradient descent optimization methods to form mesh structural models with high representational performance efficiently. The model tests on particle, fracture and multi‐phase rock images show that the optimized mesh model is highly similar to the original image in terms of similarity and edge fit, and the algorithm significantly reduces the short‐edge rate and improves the shape regularity of the mesh structure. Finally, numerical tests of uniaxial compression are carried out based on the optimized mesh model. The results show that the model has computational potential in numerical calculations. This method builds a procedural structure from digital images to numerical models, which can provide a reliable model basis for simulating the physico‐mechanical behaviour of heterogeneous rocks.

中文翻译：

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基于优化和迭代算法的复杂岩石结构自适应网格生成和数值验证


岩石结构建模对于表征岩石特征和研究岩石样品的破坏规律具有重要意义。为了高效构建岩石结构的高保真模型，该文提出了一种基于 Voronoi 结构的自适应网格解剖算法。应用图像处理技术，包括灰度、阈值分割和边缘检测，将原始岩石图像简化为特征边缘图像。然后，生成特征图像的概率密度图，为后续网格种子点的扩散提供了概率基础。此外，建立了多边形表示率的概念和四维度量的网格质量评价系统，为初始网格的种子点参数提供建议值。通过重心迭代和梯度下降优化方法对初始网格进行持续优化和迭代，以高效形成具有高表示性能的网格结构模型。在颗粒、裂缝和多相岩石图像上的模型测试表明，优化后的网格模型在相似性和边缘拟合方面与原始图像高度相似，算法显著降低了短边速率，提高了网格结构的形状规则性。最后，基于优化的网格模型进行单轴压缩的数值试验。结果表明，该模型在数值计算中具有计算潜力。这种方法构建了从数字图像到数值模型的程序结构，可以为模拟非均质岩石的物理力学行为提供可靠的模型基础。