Cutting Mechanism Of Rock-Soil And The Compound Vibration Numerical Simulation Research Of Shield Cutter Head

Shield machine is a large complete set of equipment with a variety of functions in underground tunnel excavation.As one of the core parts,the shield cutter head play a important role in excavation of soil,stability constraints,mixing waste residue and so on.In the research of shield cutter head cutting mechanism has important significance to enhance the working efficiency of the shield machine.So shield cutter head vibration cutting model is put forward,through the design and selection of shield cutter head,the analysis of cutter path,realize the vibration cutting by change the peripheral speed and advancing speed.Then through analysing cutter cutting mechanism of rock fragmentation in-depth,combine the theoretical modeling,and using the method of the LS-DYNA finite element dynamic simulation software to find out the load changes during the cutting process.The main research contents and results were as follows:1.The research of shield cutter head system simulation.For engineering geological conditions,by analyzing cutters loading mode,summarizing the experiences of engineering to complete the small shield cutter head design and cutter configuration.The cutter head meet a series of demands about the mechanical properties,vibration properties.2.Shield cutter head vibration cutting dynamics simulation.By building the mechanical model of the cutters,analyzing the motion track,studying the drag reduction mechanism of vibration cutting and the soil material model,set up the cutting model both cutter and cutter head in LS-DYNA,and add sine excitation to change the peripheral speed of cutter head,through the combination of theoretical calculation and numerical simulation to achieve the cutting stress and energy consumption,compared with uniform cutting model.The research indicated that adding vibration can help reduce the cutting stress,but it can't make sure that energy consumption down.3.The orthogonal experiment analysis of vibration parameters and vibration parameters optimization research.Through the analysis and selection of the vibration parameters,taking equivalent stress and energy consumption as measure,do simulation experiments repeatedly to match optimum solution,analysis the degree the vibration parameters affect the cutting performance,and get the best cutting effect.The optimal vibration parameters can not only make cutting stress drops,but also can reduce energy consumption effectively.4.Put forward the shield cutter head compound vibration model.Add the sine load both on peripheral speed and advancing speed at the same time,compared with the results of one vibration load.The results showed although this work mode help to further optimize the cutting performance,but the vibration parameters have interaction effect,should avoid the two frequency of vibration close to each other.The way of putting vibration cutting technology to the shield tunneling process can effectively improve the cutting performance,and laid the foundation of shield cutter head compound vibration work mode at the same time.