Hierarchical Modeling and Dynamic Analysis of Cutterhead Driving System in TBM

： Hierarchical modeling method of cutterhead driving system in tunnel boring machines (TBM) is proposed. Considering the nonlinear factors such as motor operating performance, time-variant mesh stiffness and mesh error, dynamic model of whole cutterhead driving system is established based on the dynamic similarity theory. Dynamic characteristics of key components are analyzed under motor start-up phase, rated load and impact load. The results show that vibration of each component mainly happens near multiple mesh frequency and the maximum amplitude of dynamic meshing force appears at multiple mesh frequency. Moreover, the fluctuation of dynamic meshing force increases with the external excitation. Based on the test-bed of TBM cutterhead driving system, vibration response of key components under different rotate speed is measured. The results show that mesh frequency and its multiple frequency are the main vibration frequency in the vibration of cutterhead driving system, which can verify the applicability of hierarchical modeling method. The analysis result can also provide theoretical basis in the dynamic design of TBM cutterhead driving system.