An AE-based breakage rate calculation method for granular material compaction test

Abstract This study investigates the confined compression behavior of broken coal samples by introducing novel real-time (RBR) and instantaneous breakage rates (IBR) derived from acoustic emission (AE) monitoring, thereby overcoming the limitations of traditional breakage rate (TBR) methodologies. Through uniaxial confined compaction tests across four particle size groups, AE data revealed that breakage events follow a normal distribution during loading, enabling RBR/IBR derivation via fragmentation event statistics. Key results demonstrate: (ⅰ) particle size critically governs breakage resistance, with both TBR (64.7% → 36.1%) and RBR (58.71% → 30.72%) exhibiting exponential decay as size increases; (ⅱ) small particles (0–10 mm) paradoxically show higher breakage rates due to limited coordination numbers and concentrated stresses, while large particles (10–20 mm) form stable skeletal structures that disperse stress; (ⅲ) RBR resolves TBR’s inherent errors by eliminating sieve-induced particle loss and arbitrary minimum-size assumptions, while dynamically capturing breakage evolution; and (ⅳ) loading rate alters RBR’s temporal distribution (peak height increase, deviation decrease at higher rates) but negligibly impacts rate-invariant breakage potential under confined failure, resolving ambiguities in Einav’s fractal-based theory. This AE-based approach provides unprecedented insights into dynamic fragmentation mechanics, advancing real-time characterization of granular media behavior.