Vibration Characteristics Analysis Of TBM Cutter-Head System And Research On Tunneling Testing

Full face rock tunnel boring machine, TBM, crushes rocks by the cutters which driven by the rotated cutter-head. It is the most advanced tunneling equipment with the characteristics of high efficiency, safety, economical and less pollution. TBM cutter-head is the heaviest part of the tunnel boring machine, and its working conditions are poor. It is one of the most important components of TBM. TBM cutter-head is the mounted carrier of cutters, bears the entire crushing rock loads. The cutter-head has a strong impact load, high torque, high randomness and other characteristics due to the nature of the rock with high strength, high wear resistance, and high confining pressure. Vibration is one of the reasons that cause cutter-head fatigue failure. Larger vibration will affect the TBM tunneling efficiency, lead to seal failure of the main bearing, and lead to the local damage of the cutter-head. Therefore, it is very critical to study the dynamic behavior of the cutter-head.This thesis took mechanical vibration and motion stability as the theoretical basis, studied inherent characteristics, dynamic response, vibration characteristics and stability of the TBM cutter-head system with numerical analysis methods matlab. Based on these studies, the article further analyzed the influence of different forms of cutter-head structure, construction parameters and other factors on the dynamic behaviors of the cutter-head. Eventually the results were compared with the actual engineering data to verify the correctness of the theoretical methods. This article provided a theoretical basis to dynamic optimization design, vibration control and structure design of TBM cutter-head. The main research contents are as follows:Firstly, different modes of disc cutters are simulated with the dynamic analysis software Ls-Dyna. It considers the influences of geological parameters, construction parameters, confining pressure and other factors on the cutter loads. The cutter-head loads synthesized of the single cutter loads and it provides external stimulus to the cutter-head system.Secondly, the lumped parameter method is employed to establish the bend-twist-axis-swing coupled nonlinear dynamics model of cutter-head system. The model is established after comprehensive considering the factors associated with time-varying mesh stiffness, dynamic transmission error, supporting stiffness, flexibility of planet carrier and damping. The differential equations of the system are derived by analyzing the relative displacement relationship between each component. Meanwhile, the parameters in the equations are analyzed in details.Thirdly, the natural characteristics, dynamic responses and stabilities of the TBM cutter-head system are analyzed. The characteristics of each vibration mode are summarized and it provides a theoretical basis to avoid system resonance. It uses numerical integration methods to solve the cutter-head system to get the vibration response of each component. Nonlinear time-varying cutter approach stability criterion is proposed, and it provides a basis for the parameters matching. Cutter structures, construction parameters and other factors are analyzed to the dynamic response of the cutter-head based on the previous chapters. It provides a reference to cutter design, vibration control and selection of the construction parameters.Forthly, it selects the sensor type and designs the sensor installation through study the construction environments. It compares the engineering and theoretical data to verify the correctness of theoretical methods. The results provide a theoretical basis to optimize the dynamics, vibration control and the structure design of the cutter-head system.