Mechanical Performance Analysis Of TBM Cutter-head Based On Symmetrical And Asymmetrical Disc Cutter

The Tunnel Boring Machine(TBM)is more and more widely used in underground tunnel construction due to its safety,high efficiency and environmental protection.The cutter head is located at the forefront of the TBM and is subject to uneven loads caused by the disc cutter breaking the rock.Disc cutter wear,cutter-head deformation and main bearing damage may occur.In order to ensure that the disc cutter,cutter-head and main bearing are not damaged and the tunnel is constructed smoothly,it is necessary to analyze the force and wear of the disc cutter on the cutter-head to ensure the strength and rigidity of the disc cutter and avoid excessive deformation and vibration of the disc cutter.Based on the actual engineering of the Qinling TB880E cutter-head,this paper uses the finite element software ABAQUS to establish a physical model of the rock-cutter,which studies the force characteristics of the TBM cutter-head under symmetrical and asymmetrical cutters.Firstly,the simulation of the easy-to-wear edge disc cutter is carried out to find the optimum edge inclination of the edge disc cutter.Secondly,not only the mass scaling factor of the cutter-head during the simulation process is determined,but also the uniform load analysis is applied to the cutter-head.Its strength and rigidity;Finally,the application of the asymmetric disc cutter to the entire cutter-head and the symmetrical disc cutter,researching the cutter thrust,torque,unbalanced load and disc cutter deformation,and analyzing the disc cutter force according to the actual engineering case.The relationship with wear provides a certain reference and basis for the structural design of the cutter-head.The main work of this paper is as follows:(1)The development and application history of full-face rock tunneling machine at home and abroad,as well as the domestic and international research status of edge disc cutter rock breaking,cutter-head mechanical properties and cutter-head simulation analysis are summarized.The full-section rock road header is described.Classification,selection,working principle,cutter-head system composition and cutter main parameters are summarized and deduced for the rock-crushing force model of the disc cutter,the edge angle of the disc cutter and the force theory,and the mechanical load-bearing theory of the cutter-head.(2)The edge hob rock breaking simulation model is established by ABAQUS software,and the three-direction force(vertical force,rolling force and lateral force),rock breaking volume and specific energy consumption of the edge disc cutter are extracted and analyzed,and the edge roll is analyzed.The change trend of the three-way force of the knife is used to verify the correctness of the model.Then,the influence of the-change of the tool edge angle on the rock breaking efficiency of the edge disc cutter is studied,and the edge angle of the edge disc cutter is optimized.(3)According to the actual construction of the TBM cutter-head of Qinling TB880E,the rock-cutter physical model is established by PROE three-dimensional software.Firstly,the rigidity and strength of the cutter base of the ABAQUS software are analyzed.Then,the TBM cutter-head is used.Boundary conditions were applied to analyze the excavation process(including rock damage,three-direction force of each disc cutter,cutter head thrust and torque).Finally,the correctness of the rock-cutter simulation model was verified by comparing the simulated values with the theoretical values.(4)By applying certain boundary conditions to the cutter-head,study and compare the thrust,torque,unbalanced load and disc cutter deformation of the asymmetric cutter-head and all the asymmetric cutters of the replacement disc cutter,and explore the symmetric cutter and the asymmetric cutter.The deformation characteristics and laws of the disc;meanwhile,the relationship between the force and wear of the disc cutter is studied according to the actual engineering case.