A Peridynamic Framework for Modeling Progressive Failure in Porous Sandstone Indentation

ABSTRACT A state‐based peridynamic model is proposed to simulate the failure mechanisms in porous rocks, using Bentheim sandstone as a specific example. Experimental observations reveal a transition from brittle to ductile failure under increasing triaxial compression. This behavior is attributed to pore compaction. The peridynamic model is enhanced to capture the strain hardening observed in hydrostatic compression experiments and calibrated to reproduce pore‐collapse behavior. Rock heterogeneity is incorporated through Weibull‐distributed strength parameters, reflecting the stochastic nature of material properties. Simulations of indentation tests for four specimen sizes demonstrate the predictive capability of the model. A qualitative validation is established through acoustic emission data, while a quantitative validation relies on the comparison of numerical force–penetration and indentation pressure–penetration relationships with experimental results. Beyond reproducing macroscopic force responses, the model captures the spatiotemporal evolution of the compaction zone, and an energy‐based analysis shows that grain comminution prior to failure contributes significantly to the total energy dissipation.