Structural Optimization Design And Numerical Simulation Of The Cutter Head Of The Shield Machine

The shield machine was a special mechanical equipment for subway tunnel excavation,The cutter head was one of the key components.In this paper,a subway earth-pressure balanced shield machine(EPB)spoke plate cutter was taken as the research object,it was mainly to find the best construction parameters and corresponding opening rate of the cutter head of the shield machine,and provide some technical guidance for the construction.According to the geological conditions of this section,two numerical simulation schemes were proposed.Firstly,the dynamic numerical simulation method was used to study the relationship between the digging speed,rotation speed and soil loss to total amount ratio;Secondly,based on discrete element numerical simulation method(DEM),the relationship between the speed of cutterhead,the cutter opening ratio and the efficiency of the soil in front entering the soil chamber was studied.This paper mainly obtains the following research results and conclusions:(1)According to the Archimedes helix and the equal life principle of the cutter,considering the load balance and structural symmetry of the cutter head,the layout of the six bars of the cutter head was completed.(2)The numerical simulation experiment of cutting soil by cutterhead was conducted based on ABAQUS finite element analysis software.The Mises stress,equivalent plastic strain(PEEQ)and mass cutting rate of the cutterhead under cutting conditions were analyzed,regression analysis was carried out on the relationship among the rotary speed of cutter head,digging speed and soil loss to total amount ratio.(3)Comparison results of stress-strain curves of silty sand layer were obtained through discrete element triaxial test and large indoor triaxial test,to calibrate the microscopic parameters needed for discrete element numerical simulation of shield tunneling simulation.(4)3D shield model was imported into EDEM discrete element software to establelish 3D discrete element particle model of shield excavation.The flow performance and wear amount of the cutterhead with different opening rate of cutterhead are analyzed,analysis of inlet pressure of screw conveyor and static strength of cutter head.Regression analysis was used to fit the mass and efficiency of digging soil into the soil chamber,and the mathematical model equation between them was obtained.