Numerical investigation of the influence of mineral mesostructure on quasi-static compressive behaviors of granite using a breakable grain-based model

Abstract

The mesostructure of brittle rocks, such as granite, plays a vital role in determining their mechanical properties and failure mode. Understanding the influence of rock mesostructure on mechanical behavior requires a realistic representation of grain size distribution, grain shape, and average grain size. In this study, we developed a breakable polygonal discrete element model that incorporates mineralogical composition, grain size distributions, and grain shape to simulate the rock mesostructure. Numerical specimens with varying mesostructures were created to represent different grain size, shape, and distribution characteristics. Quasi-static uniaxial compressive loading tests were conducted on these specimens to analyze their peak strength and macroscopic failure modes. The results revealed a strong linear relationship between the quasi-static compressive strength of the rock and mesostructure parameters, including average grain size, grain size coefficient, and grain roundness. Additionally, the simulation results demonstrated that the rock mesostructure significantly influenced the quasi-static compression failure mode. The proposed breakable polygonal discrete element model has the potential to predict the macroscopic behavior of brittle rocks accurately. It provides a reliable method for studying the effect of mesostructure on the quasi-static compressive mechanical behavior of rocks.