Dynamic Response Analysis Of Disc Cutter In Different Positions Of TBM Cutterhead

The disc cutter of TBM is mounted in frront of the cutterhead to cut the rock.The working life of the disc cutter directly affects the tunneling efficiency of the TBM.Studying the dynamic load of the disc cutter in different positions of the TBM cutter disc and the dynamic stress and strain under the dynamic load are of great significance for optimizing the layout of the disc cutter and the cutter,improving the disc cutter drilling performance and service life,and reducing the construction cost.In this paper,the front double-edged disc cutter cutting provided by a shield cutter company is taken as the research object.Based on the multi-body dynamics simulation platform RecurDyn,the actual cutting state of the disc cutter is simulated,and the rock-breaking simulation model of the disc cutter in different positions is established to analyze the inside of the cutter ring.The dynamic response and its effect on rock breaking efficiency are analyzed,and the disc cutter wear and failure mechanism are analyzed.The specific research work is as follows:The disc cutter model was built using the 3D modeling software Creo,including the central shaft,seals,bearings,end caps,cutter rings and other components.The discrete element simulation is used to obtain the three-way dynamic load of the disc cutter;the disc cutter cutter is set as a flexible body,and the external three-direction force load is loaded to analyze the dynamic stress of the disc cutter in the same cycle and in different cycles.The simulation result and the actual roll The force condition of the knife fits together,indicating the reliability of the loaded dynamic load,which lays a foundation for the subsequent rock breaking mechanism and analysis of the influencing factors of rock breaking efficiency.The assembly method of the 3D cutting rock mass model of the disc cutter in different positions of the TBM is proposed.A flexible soil-based geotechnical model was established in Recurdyn that geotechnical material parameter setting and meshing were performed.Disc cutter cutting models were created,including rigid body modeling,FDR element modeling,constraint modeling,contact modeling and Motion parameter settings.The rock mass simulation experiments of the central disc cutter,the front disc cutter and the edge disc cutter were carried out.Each disc cutter was operated under three motions of rotation,revolution and propulsion,and the dynamic stress at each node inside the cutter ring was discussed.The trend of time changes and the influencing factors of dynamic stress changes.The stress value of the point closer to the rock mass on the center disc cutter cutter ring is larger,and the stress value of the observation node varies greatly in the same time range;By analyzing the growth trend of the stress in the first three cycles of the front disc cutter,it can be estimated that the stress peak of the fourth cycle is about 2000 MPa,and the depth of cut should be controlled within a reasonable range of 25 mm to 50 mm.When the edge disc cutter is subjected to a large partial load,the internal structure of the rock is unevenly distributed.The side of the edge disc cutter is likely to wear faster on the side below the rock mass,which is prone to lateral eccentric wear.Furthermore,the life of the disc cutter has a significant impact.The rationality of the simulation results is verified by four sets of field experimental data.The control variable method is used to analyze the influence of two single factors of propulsion speed and cutter speed on the internal dynamic response of the edge disc cutter.If the same tunneling distance is used,the smaller stress value of the disc cutter when the smaller tunneling speeds is used,which proves that the relative motion between the disc cutter blade and the rock mass is reduced,and the life of the disc cutter is extended.Therefore,the speed of advancement should not be too large.When the cutter wheel rotation speed is small,the three-way force decreases with the increase of the rotation speed,and the reduction range is relatively large,and the axial force of the disc cutter is relatively reduced compared with the normal force and the tangential force,therefore,the influence of the cutter wheel speed on the axial force is greater.When the rotational speed of the cutter increases from 4 r/min to 5 r/min,the change in the magnitude of the three-direction force is proportional to the rotational speed,but the change in the three-direction force at the two speeds is not obvious.In order to prevent excessive frictional contact between the disc cutter and the rock mass,reducing work energy consumption and reducing unnecessary wear of the rock slag on the disc cutter,moderate tunneling speed and cutter speed should be selected during the tunneling process.