Research On The Rock Cutting Performance And Dynamics Of Vibrational Disc Cutter

In order to realize the safe and efficient mining of coal and rock,improve the ability of cutter to break rock and the efficiency of roadway excavation,and reduce cutter wear,the vibration technology was introduced into the disc cutter cutting to break rock,and the method of vibrational disc cutter cutting rock was proposed.In this paper,theoretical analysis,experiment and numerical simulation are used to study and analyze the performance of disc cutter in cutting rock.Based on the rock breaking characteristics and the theory of rock broken by TBM cutter rolling,the rock broken by cutter cutting is studied and the rock breaking process is analyzed.The mechanical model of cutter cutting rock is established based on Boussinesq's problem and J integral,and the mechanical model of the peak thrust force in the process of cutter cutting rock is obtained.The cutting thickness,rock intrusion angle and rock properties,which affect the cutting performance of the cutter,are experimentally studied to determine the influence of related parameters on the cutter load and the specific energy consumption of rock breaking.According to the measured rock mechanics parameters,the micro-parameters of the discrete element model are calibrated,and the numerical simulation model of cutting rock is established.The numerical simulation model is in good agreement with the experimental results.Using the numerical simulation model to analyze the process of cutting rock,the optimal cutting thickness range and the optimal cutting edge width range were determined by taking the unit millimeter thrust force and specific energy consumption as the evaluation indexes.A rock-breaking test rig for cutting of the rotational disc cutter was established to analyze the influencing factors of the rock cutting performance of the disc cutter,and determine the influence of the cutting thickness,the speed of the disc cutter and the moving speed of the disc cutter on the cutting performance of the rock,and combine the average load and ratio evaluation indicators such as energy consumption,the volume ratio of broken rock occupied by dust,and cutting rock breaking speed have determined the optimal cutting thickness range,optimal speed range and optimal moving speed range under given conditions;On the basis of the rotary cutting of the cutter to break the rock,vibration is incorporated into it.The results show that:compared with no vibration,the vibration of the cutter can greatly improve the rock breaking performance.Based on springs,damping,masses and sliders,a low-dimensional dynamic model and a high-dimensional dynamic model of rock cutted by the vibrational disc cutter are established,and these two models are solved separately to obtain the bifurcation diagram,velocity displacement diagram,Poincaré cross-section diagram and phase space trajectory diagram of the system under different control parameters.The results show that: when the disc cutter cuts the rock with the highest efficiency,the system is in the P-1-I-1-Pr-1 motion state;the low-dimensional system can better realize the selection of the best parameters of the static force and the dynamic force amplitude;The selection of the best parameters of the excitation frequency should fully consider the resonance phenomenon between systems;the high-dimensional dynamics model is more in line with the actual situation.This thesis has 124 pictures,12 tables,149 references.