Work

Research on Coal Cutting and Fragmentation Characteristics Based on Heterogeneous Model

Year: 2026

Type: article

Abstract: The inherent heterogeneity of coal significantly influences cutting efficiency, directly impacting energy consumption and dust generation in mining operations. To investigate this effect, this study established a heterogeneous coal model using PFC 2D 5.0, assigning strength parameters based on the Weibull distribution. The influence of the heterogeneity index (λ) on macroscopic strength, brittleness, and micro-crack propagation during coal cutting was systematically analyzed, and comparisons were made with homogeneous models of varying uniaxial compressive strength (UCS). The results show that as λ increases, both UCS and Brazilian tensile strength (BTS) increase exponentially, approaching the values of the homogeneous models, with BTS exhibiting greater sensitivity to λ than UCS. The brittleness index also increases with λ. During cutting, a higher λ leads to more concentrated crack propagation and stress distribution, as well as a reduced proportion of shear cracks, indicating a shift toward a more controllable fragmentation mode. Correspondingly, the specific energy (SE) for cutting decreases monotonically with λ, reflecting enhanced cutting efficiency, a trend attributed to the reduced energy dissipation from shear friction and the homogenization of internal stress distribution. Compared with homogeneous models, the heterogeneous models produce a more complex crack network and a greater number of cracks at lower strength levels, though these differences diminish as λ increases. These findings provide theoretical insights for optimizing cutting parameters to reduce energy consumption and minimize uncontrolled fracturing in efficient coal resource exploitation.

Source: Processes

DOI: 10.3390/pr14101624