Development And Similarity Verification Of TBM Disc Cutter’ Cutter Ring-rock Grinding Scale Test-bed

During the tunneling process of a full-face rock tunnel boring machine(hereinafter referred to as TBM),the disc cutter(hereinafter referred to as disc cutter)mounted on the cutter head directly contacts and cuts the rock by its cutter ring,so the wear resistance of the cutter ring determines the disc cutter the comprehensive rock breaking performance has become one of the key factors affecting the construction efficiency of the project.It is an important research approach to improve the wear life of the disc cutter to obtain the law of friction and wear of the disc cutter ring by carrying out the cutter-rock pair grinding test.However,due to the large size of the disc cutter and the radius of rock breaking by rolling,and the complicated process of cutting and rock breaking,the material loss rate of the cutter ring is relatively slow.Therefore,it is not practical to carry out the tool rock grinding test on the existing full-scale TBM rock breaking test-bed.At present,there is still a lack of a test rig that can reproduce the actual cutter-rock action process.How to develop a highly similar and economical and reliable TBM disc cutter cutter ring-rock counter-grinding test rig is a key problem for domestic and foreign scholars to be solved urgently.In response to the research needs of TBM disc cutters for reducing friction and increasing life,this paper systematically investigates and analyzes the development status of domestic and foreign TBM tool cutting performance test benches and their preparation technology.Based on the theory of acquaintance,a cutter ring-rock is developed.On the scale test bench,and with the aid of the test bench,the research and similarity verification of the cutter ring sample and the rock test were carried out.The main research work of this paper is introduced as follows:(1)The kinematics and cutting load characteristics of the cutting edge of a 17-inch inner disc cutter with a constant cross-section edge shape in the process of rockbreaking by rotary rolling are analyzed.Based on the rock-breaking mechanism of the disc cutter,the geometric dimensions of the edge and the cutter ring are reasonably selected.Parameters such as material,hardness,tool cutting load and tool-rock contact stress level are regarded as similar characteristic parameters.(2)With the aid of the nonlinear transient dynamics software ABAQUS and based on the DP rock material constitutive model,a finite element rock-breaking model by the cutter ring sample was established to simulate the quasi-static rock intrusion and rolling rock breaking process of the cutter ring sample.The cutting load level of the cutter ring under different cutting conditions was determined,and the limit working load of the test bench was determined.At the same time,combined with the Hertz theory,the CSM model was used to calculate the cutter-rock contact stress,and the simulation value was compared and analyzed to determine the test.The value of the contact stress level simulated by the platform provides basic load data for subsequent development of the test platform.(3)According to the selected similar characteristic parameters,the disc cutter cutter ring-rock to grinding scale ratio test bench was built,including the power propulsion device,the disc cutter clamping device,and the rock fixing device.Among them: the power propulsion device and the rock fixing device were ingeniously borrowed the crank slider structure of the B665-2 bullhead planer and the screw clamping mechanism of the vise can be used to achieve 6-speed cutter rock grinding speed.At the same time,the transmission accuracy of the gear and the screw of the feeder part of the planer ensures the penetration the control accuracy of test parameters such as penetration and rock penetration speed effectively saves test costs and improves the accuracy of cutter-rock alignment.Finally,using static finite element analysis technology to check the rigidity and strength of the weak parts of the test bench under the ultimate load,the reliability of the test bench is guaranteed.(4)The cutter ring sample-granite rolling counter-grinding test under three sets of cutter-rock counter-grinding speeds was carried out,and the rock macro-breaking characteristics,blade dynamics characteristics and blade The microscopic friction and wear morphology reveals the distribution characteristics of rock fragmentation and the friction and wear mechanism of the cutter ring.(5)Through comparison and analysis with engineering data,the mapping relationship between the scaled-scale cutter ring sample and the measured wear of the engineering disc cutter was established,and the engineering applicability of the built test bench was verified.