Improvements of Using Adaptive Voronoi Mesh in the Rock Fracture Process: Computational Efficiency and Simulation Accuracy
Jiacheng SONG#+, He LEI
Southeast University, China

The realization of numerical modeling based on the real structure of rocks is of great importance to study the fracture process and macroscopic mechanical behavior of rocks. One of the major problems in building numerical models based on rock images is that it is difficult to achieve balance between the number of mesh elements and the similarity between the model and the images. Although limiting the number of mesh elements can improve the computational efficiency, the cost of doing so is often the loss of model similarity. The improvement of similarity is mostly achieved by increasing the number of mesh elements, and it does not provide a good representation of the rock mineral grain boundary. Therefore, it is of strong theoretical and practical significance to propose a modeling method that can balance the number of mesh elements and model similarity while providing a good representation of rock mineral grain boundaries.In this paper, various image processing techniques were applied to turn the original rock image into image of feature boundary for post-processing. And then use the gradient descent method to fuse the Voronoi polygon with the rock image according to the characteristics of the pixel value changes in the grayscale map of the rock image. Finally, a high-quality model with a high degree of similarity to the rock image and a relatively compact number of mesh elements is obtained. This model was then used in the numerical simulation of Brazilian splitting tests, and the final results were in good agreement with the experimental results and showed the advantage of the mesh in reproducing the crack extension of the rock failure process.