Numerical Simulation And Test Of Coal Rock Breaking By Disc Cutter Under Complex Dynamic

In order to improve the ability of the cantilever roadheader to cut the coal and rock roadway,a new method of breaking the coal and rock with the disc cutting mechanism under the compound power is put forward.The mechanism can not only improve the breaking ability of the coal and rock and the life of the cutting tool,but also reduce the dust and realize the safe and efficient driving of the coal and rock roadway.Taking the disc cutting tool as the research object,from the theory,numerical simulation and test three aspects respectively,the load characteristics of the coal rock broken by the disc cutter under the compound dynamic are studied.On the basis of rock fracture mechanics and austenite's viewpoint,the mechanical model of disc cutter tooth and wedge surface is established.The crack tip intensity factors of disc cutter tooth wedge surface and water jet fracture coal rock are superposed linearly,and the crack tip intensity factors of water jet assisted disc cutter tooth fracture coal rock are obtained.According to the vector superposition principle,the radial direction of water jet assisted disc cutter tooth fracture coal rock is constructed Mechanical model of the load.In this paper,the finite element method is used to establish the numerical model of vibration cutting coal and rock with disc cutter,and 25 sets of orthogonal numerical simulation load spectrum of disc cutter are obtained.Four evaluation indexes,peak value mean value,curve mean value,box dimension and wavelet energy entropy,are selected.The effect of motion parameters on the performance of disc cutter to break coal and rock,and the performance of disc cutter to break coal and rock are analyzed by power coefficient method and variance analysis method The significant degree of influence is feed speed,vibration frequency and amplitude.The relationship between the mean value of the peak load and the mean value of the curve,the feed speed,the vibration frequency and the amplitude is given by using the multivariate nonlinear fitting.The numerical model of coal rock radial cutting with water jet assisted disc cutter tooth is established by Using SPH / FEM coupling method.By using LS-DYNA software to simulate the water jet assisted disc cutter,it can be seen that the radial load of water jet assisted disc cutter is inversely proportional to the angle of wedge surface;the auxiliary effect increases with the increase of water jet inlet pressure;the auxiliary effect decreases with the increase of incidence angle;the nozzle diameter increases,The auxiliary effect increases,which is consistent with the results of mechanical model analysis.The results show that the radial load of vibration cutting coal and rock is proportional to the cutting thickness.With the increase of the wedge angle,the radial load of vibration cutting and single radial cutting decrease,and the radial load of vibration cutting coal and rock is less than that of vibration cutting coal and rock The relationship between the radial load of single radial cutting coal rock,the vibration cutting coal rock load and the angle of wedge surface is consistent with the numerical simulation of LS-DYNA software.Through theoretical,numerical simulation and Experimental Research on the coal rock breaking by the disc cutter under the compound power,under the action of vibration and water jet,the ability of the disc cutter to break the coal rock can be improved,and the tool load can be reduced.This research lays a foundation for the development of new cutting tools and hard rock breaking methods.