A Rate‐Dependent Stillinger‐Weber Potential‐Based Discretized Virtual Internal Bond Model for Rock Fracture Simulation Under Different Loading Rates

Abstract

Strain rate has a notable influence on the mechanical properties of rocks. Understanding these properties and how they influence rock deformation and failure under various loading rates is critical for the engineering considerations in tunnel excavation, energy resource extraction, and mining operations. A rate‐dependent Stillinger‐Weber (SW) potential is constructed on the foundation of the trilinear damage potential, considering the strain rate effect on material properties. The developed potential is implanted into the discretized virtual internal bond (DVIB) model for rock fracture simulation at varying loading rates. A number of rock tests were simulated to see how accurately the developed model could simulate rock fracture over a range of strain rates. These rock tests included direct tension, uniaxial compression, three‐point bending, and semi‐circular bending tests. The findings reveal that both tensile and compressive strengths exhibit a linear increase with the logarithmic increase in strain rate. In the uniaxial compression tests, the failure modes transition from single‐plane shear to X‐shaped shear, then to extension, and ultimately to split failure as the strain rate escalates. In the semi‐circular bending tests, the mode I fracture toughness was observed to decrease with an increasing crack inclination angle, whereas the mode II fracture toughness exhibited the trend of increasing first and then decreasing. The rate‐dependent SW‐DVIB model has been demonstrated to accurately simulate the mechanical properties and failure behaviors of rocks across varying strain rates, as corroborated by the congruence between simulated and experimental results.