Dynamic Characteristics Analysis And Experimental Study Of TBM Cutterhead Driving System

With the explosive development of modern urban rail transit construction,tunnel boring machine(TBM)has been playing a major role in all kinds of hard rock tunnel engineering with large buried depth and long distance.As a high-tech and high value added machine,TBM integrates multidisciplinary technology which includes machinery,electricity,hydraulic technology and so on.Cutterhead driving system is the core subsystem of TBM,which takes up 40% of total power and plays driving and supporting role.In tunneling process,load torque of cutterhead driving system often changes abruptly due to the complex geological condition.Under such heavy impact loading,severe vibration and uneven loading may occur in cutterhead driving system,which may cause the failure of critical part.In this paper,TBM cutterhead driving system is taken as the research object.Based on the idea of finite element,a hierarchical modeling method for the dynamic analysis of TBM cutterhead driving system is proposed.The driving torque properties of multi-motor driving system and the mechanism of coupling vibration of system under heavy impact excitation is studied.The influence of the system parameters on dynamic characteristics is analyzed.And the accuracy of theoretical result and applicability of hierarchical modeling method is verified by the vibration test of tunneling field and model test stand.The main research work is as follows:1)Based on the idea of finite element,a hierarchical modeling method for the dynamic analysis of TBM cutterhead driving system is proposed.The whole system is divided into control system and mechanical system.For control system,the model of multi-motor driving system is established with master-slave control structure.For mechanical system,virtual axis equivalent method based on the dynamic similarity theory is adopted to build gear meshing element,shaft element,supporting-connecting element model.According to the assembly relationship,all the finite element models are coupled to build the whole dynamic model of TBM cutterhead driving system.2)Based on the whole dynamic model of TBM cutterhead driving system,a heavy impact load in tunneling field is chosen to simulate and the torque characteristics of multi-source inverter motor under master-slave control is studied.Under such heavy impact torque,vibration responses are calculated through precise integration method and numerical method.Dynamic characteristics of critical part are analyzed and the influence of system parameters on dynamic characteristics is studied.3)Vibration test of TBM cutterhead driving system is conducted through tunneling field and model test stand.A model test stand of the cutterhead driving system is designed and built based on the similarity theory.The vibration responses under different driving speed and driving torque are tested and the test results are compared with the theoretical analysis results to verify the applicability of hierarchical modeling method.