Discrete Element Method Simulation And Experimental Investigation On The Cutting Process Of Rock And Soil

With the growing demand of underground space development, shield tunnelingmachine plays an increasingly important role in the construction of tunnel engineering.Cutter tool as the main working parts of shield machine, its cutting and crackingperformance often determine the efficiency and cost of engineering construction,while the load on cutter is a key factor affecting cutting performance in the process ofcutting. This paper starts with the cutting mechanism of rock and soil, using themethod of discrete element simulation and experimental research to do furtherresearch on the cutting process and load on cutter, provide a certain basis for theoptimization of structure parameters and cutting parameters to improve cuttingefficiency and prolong the service life of cutter.This paper mainly do the following research work:The first chapter introduces the structure and working principle of different kindsof shield machine, and the cutting mechanism of rock and soil were summarized, theresearch process of rock and soil cutting using numerical simulation method werediscussed both at home and abroad, the advantage of using discrete element method toresearch rock and soil cutting problem was analyzed, and the research significance ofthis paper were put forwarded.The second chapter combined with the characteristics of rock-soil and DEMtheory, the cluster method was introduced to establish the discrete element model ofrock and soil, and the microstructure parameters of soft rock and soil were calibrated.In the third chapter, the model of soft rock cutting was established combinedwith the features of rock cutting and the cutting process was dynamically simulated,the crack generation and propagation were monitored. The orthogonal simulation testtable with four factors and four levels was established, and the effects of load oncutter was analyzed which included the cutting speed, the penetration of cutter, thefront angle of cutter and the cutting edge radius. The structure parameters and cuttingparameters of cutter were optimized.The fourth chapter deals with the experimental verification of soft rock cuttingsimulation. The horizontal and vertical forces were calibrated, three groups of cuttingexperiment were made using rotary cutting experiment system, and the results werecontrasted with simulation results, so the reliability of c utting process and the accuracy of results were verified.In the fifth chapter, the flow forms of soil during the cutting process wereintroduced, the DEM cutting model of soil was established, the orthogonal simulationtest table with four factors and four levels was established, and the effects of load oncutter was analyzed which included the cutting speed, the penetration of cutter, thefront angle of cutter and the cutting edge radius. The structure parameters and cuttingparameters were proposed reasonably during the cutting process of soil.Finally, the whole content of this paper was summarized, and further study wasproposed.