Coupling Dynamic Characteristics Research Of TBM Cutter Head System Under Uncertain Factors

The full face rock tunnel boring machine(TBM)is a large and complex equipment,which is widely used in the construction of water conservancy,transportation,national defense,energy and other underground projects.The vibration of the TBM in the construction will cause the fatigue damage of the parts.The cutterhead system is the most critical part of TBM,so the engineering failure will greatly affect the project progress,increase the time and the cost of money.So the vibration problem of the cutter head system needs to be solved urgently.Because of the complex structure of the cutter head system and the uncertainty of the field service environment,the uncertain factors in tunnelling process of cutters and the uncertainty of manufacturing process,the dynamic characteristics of the cutterhead system is more difficult to predict in the extreme environment,furthermore,the difficulty of vibration reduction and damage resistance design is increased.Therefore,it is very important for analyzing the dynamic characteristics of TBM cutter head system with uncertain factors to the vibration reduction optimization design of TBM.In this paper,the vibration characteristics of TBM cutterhead system with uncertain parameters are studied.The main work of this paper is as follows.(1)Uncertain factors analysis and calculation of external excitation boundary of TBM cutter head system.Improving the limitations of traditional calculation method based on accurate assumptions,the uncertainty factors of the cutter head system are analyzed in detail,The uncertainty geological condition model and cutter location distribution model are established.The uncertainty of external load is treated by interval analysis method,and the calculation method of the load boundary of the cutter head under different working conditions is derived,which provides the load input conditions for the subsequent dynamics analysis considering the uncertain factors.(2)Multi-degree of freedom coupling dynamic characteristics of TBM cutter head system are studied under the influence of uncertain factors.On the basis of multibody dynamics,considering the influence of uncertain external excitation,time-varying meshing stiffness and multi-degree of freedom coupling of particles,a multi-degree of freedom coupling dynamics model of typical TBM cutterhead system with uncertain excitation is established.It provides a basis for effectively describing the complex vibration shape and studying the dynamic characteristics of cutter head under uncertain excitation.(3)Based on interval model,the method of solving dynamics differential equations under uncertain excitation is studied.And the process for calculating the dynamic boundary of vibration response is derived by combining the central difference method with interval analysis method.It provides an effective solution for the dynamics analysis of the cutterhead with uncertain excitation.(4)Taking the cutterhead system designed by a project as example,the dynamic characteristic analysis is carried out by the theoretical method in this paper.The vibration response of the cutter head are calculated,and the necessity of considering the uncertainty factors is analyzed.The influence of cutter structure forms,center block mass and driving gear arrangement form on cutter head’s vibration response is studied.It provides theoretical reference for the safety assessment,structure design and vibration reduction optimization design of the cutter head,and the validity and practicability of this method and model are verified...