TBM's Multi-degree Coupling Dynamics And Testing Verification

Full face rock tunnel boring machine (TBM) is the factory assembly line tunnel construction equipment combined machine, electricity, liquid, light system. It has advantages of fast tunneling speed, high comprehensive that can realize long buried depth tunnel construction under complex geomorphic. The main system is the core part of TBM, which plays the role of cutterhead's rotating and promoting. Its dynamic performance determines the TBM tunneling efficiency and service life of the machine directly. Due to the high hardness, host's high torque and thrust drives during tunneling, TBM's main driving system often withstand strong impact load from the cutterhead which leads to the extreme vibration. Hence, the study on TBM main system is of great significance for TBM anti-vibration design.This paper established multi-degree of freedom coupling nonlinear dynamic model for TBM's main driving system based on the horizontal supporting open TBM main driving structure. The time-varying stiffness, the complex relationship from cutterhead to the girder support boots is considered.The process of rock fragmentation is simulated by Ls-Dyna.The equivalent load is compounded by cutter's three-dimensional load. The calculating load is corrected by the actual load parameters under the same driving parameters. The load is taken as input load for the dynamic model. At the same time, a set of field test system which can accurately test each parts'vibration data, especially the cutterhead under bad tunneling condition is established. The vibration is measured based on Liaoning northwest engineering T6 period. The stiffness value of dynamic model is amended by the test data.Based on the dynamic model revised by the field test, the dynamic characteristics of main system are calculated under cutterhead's rotating speed 5-6 RPM and advancing speed 3 m/h. The input parameters are based on the actual structure parameters. By analyzing the time domain and frequency domain response of key parts, each part's average vibration magnitude and the vibration transfer law is determined. The cutterhead's three-dimensional average vibration is between 0.35 mm to 1.2 mm, the largest is the axial vibration, lateral is the horizontal vibration, and the minimum is the longitudinal vibration. The vibration passed along the axial direction of support decreased by 43% in the main girder. The vibration frequency of cutterhead and other major components is 0 to 5 Hz which shows it's an obvious forced vibration. Then for cutterhead's drive systems, the influence of pinion's layout, gear shaft length and cutterthead's rotation speed parameters on driving system vibration situation and it's equal load property is studied. The research provides a theoretical reference for vibration reduction design.Finally based on the dynamic model, electromechanical coupling dynamics model is established on the basis of real-time torque transmission. By solving the original coupling model, this paper obtained the changes of input load under a computation period and laid a foundation for further research.