An adaptive damage smear method for modelling the meso-fracturing process of rock

Numerical methods based on continuum mesoscopic representative volume elements (RVEs) are popular in simulating the rock fracturing process because they can characterize trans-scale crack propagation. However, two key prerequisites must be satisfied to achieve good performance from RVE-based smear methods: the minimum representation element must be a square, and the RVE size used to represent cracks must be close to the meso-scale. Thus, overcoming the serious computational burden caused by rock meso-fracturing modeling has become a long-term bottle-neck issue. This study aimed to develop an adaptive downscaling modeling scheme for the scale restriction of rock meso-fracturing systems based on a local hierarchical refinement strategy and novel combined estimator advancements. Subsequently, based on the statistical meso-damage smear method, we simulated the adaptive meso-fracturing process of the rock. The results of several examples show that the adaptive damage smear method ensures the stability and conti-nuity of the stress field in the stress concentration area of the model as well as enhances the computational accuracy. Additionally, the local downscaling refinement meshes used to cover the crack propagation path approach the expected mesoscopic scale required to characterize the failure morphology at a high resolution. Consequently, an optimal trade-off between the accuracy and computational effort can be realized. Compared to the global uniform fine model with the same resolution, the proposed adaptive strategies can significantly mitigate the computational burden.