Theoretical mechanical model and load characteristics of coal and rock vibra-tion cutting with disc cutter

Aiming at the problem of short life and low efficiency of coal rock cutting machine,a method of cutting coal and rock with axial vibration and radial cutting is proposed to investigate the mechanical properties of the disc cutter in the axial vibration and radial cutting of the fractured coal-rock,the mechanical model of breaking coal and rock with disc cutter is constructed according to the criterion of ultimate strength per unit fracture surface and minimum energy method based on the analysis of caving area and equivalent caving angle and the concentrated force of load and its action position angle. Based on the extended linear Drucker-Prager plastic constitutive model,the stress cloud and load characteristics of the disk rock crushed is simulated using the ABAQUS software. The discs under different cutting thicknesses are tested on the vibration cutting test bench by setting parameters such as vibration frequency and amplitude. The load spectrum of the broken coal rock of the disc cutter,the numerical simulation and the load characteristics of the crushed coal rock of the disc cutter are extracted. The average value of the theoretical model calculation value and the numerical simulation load peak mean value and numerical simulation peak value are compared and analyzed.The results show that the fracture range of coal-rock broken by disc cutter is crescent shape and decreases from middle to both sides. The radial load of the cutting coal-rock is obviously smaller than that of the single-acting radial cutting coal-rock. When the disc cutter is in axial vibration and radial cutting,the average error between the theoretical model of radial load with different cutting thickness and the mean value of peak value of simulated load is 9. 12% and 4. 88% . The average error between the theoretical model of axial load and the mean value of peak value of numerical simulation load is 9. 25% ,and the average error between the theoretical model of axial load and the mean value of peak value of experimental load is 8. 34% . The accuracy of the theoretical model of the disc cutter is verified by numerical simulation and experiment.