Optimization of Mix Ratio of Mechanically Optimized Rock‐Like Materials and Verification via O‐DDARF Numerical Simulation

To address the poor adaptability of traditional rock‐like materials (artificial cement‐based specimens formulated to mimic the physical and mechanical properties of natural rock) to natural rock masses and the challenge of numerical simulations in accurately capturing rock mass failure processes, this study optimized rock‐like material mix ratios and verified them via the O‐DDARF method, using natural carbonate rock as the target. Nine carbonate cement mortar specimen groups with varied quartz sand particle‐size ratios were prepared through single‐factor parametric experimental design based on orthogonal test principles; the optimal mix ratio matching natural carbonate rock properties was screened via physical and mechanical parameter tests. An O‐DDARF‐based numerical model was constructed by introducing heterogeneous grid generation, optimized contact algorithms, and parallel computing, then validated through comparative uniaxial compression physical tests and simulations. Results showed that Group 2 (quartz sand particle‐size ratio: 8–16 mesh:16–26 mesh:40–70 mesh:70–110 mesh = 1:2:3:5) exhibited the closest mechanical parameters to natural carbonate rock, and uniaxial compression tests and simulations showed good quantitative agreement, with relative errors below 6.3% in peak strength and elastic modulus, both revealing preset cracks extending axially and local damage zones forming near main cracks. This integrated framework of material development, physical testing, and numerical simulation offers valuable references for rock‐like material optimization and numerical simulation method promotion.