Load Characteristics of Mechanical Cutters When Cutting Different Coal and Rock Formations and Entropy Features of the Samples

Abstract

The load characteristics and dynamic behavior of shearer drums under complex geological conditions—particularly coal seams with gangue interlayers, roofs, and floors—remain insufficiently understood due to the lack of systematic comparative studies across varying cutting scenarios. In this study, a three-dimensional finite element model of drum cutting was established using SolidWorks and HyperMesh, and explicit dynamic simulations were performed with LS-DYNA to investigate the triaxial loads (cutting resistance, traction resistance, and lateral force) under five distinct operating conditions. Theoretical calculations of cutting resistance for pure coal cutting yielded 91 kN, while the simulation result was 87.0245 kN, with a relative error of 4.37%, validating the reliability of the numerical model. Results reveal that gangue position exerts a differential influence on load components: upper gangue maximizes traction resistance (mean: 43.01 kN), whereas lower gangue leads to the highest cutting resistance (mean: 38.45 kN). Floor cutting, with the highest uniaxial compressive strength (75 MPa), produces the most severe load fluctuations. To further characterize the nonlinear dynamics, Ensemble Empirical Mode Decomposition (EEMD) coupled with sample entropy analysis was applied to the load signals. The high-frequency intrinsic mode functions (IMF1–2) of the floor-cutting traction resistance exhibited the highest sample entropy values, indicating pronounced impact characteristics and complex non-stationary behavior. These findings provide a quantitative basis for distinguishing cutting media (coal, gangue, roof, floor) and offer actionable insights for drum structural optimization and adaptive cutting control in intelligent mining operations.