Dynamic analysis and experimental study of a Tunnel boring Machine testbed under multiple conditions

The main drive system is the core of a Tunnel Boring Machine (TBM). The force transmission law of this system is extremely complicated, which leads to severe vibration, structural failure, and safety hazards. Therefore, the dynamic analysis and the study of the vibration transmission law of a TBM main system under different working conditions are very important. In this study, a novel testbed for a hard rock TBM main system and a multi-DOF coupling dynamics model were built by considering the external excitations of the cutters, the time-varying meshing stiffness of the gear teeth, the meshing error, the clearance, and the stiffness of the main bearing. A wireless vibration monitoring system was built on the testbed. Experiments under typical working conditions were done to verify the dynamic model. Finally, the dynamic response of the system was analyzed. The results showed that the maximum error of the theoretical and actual dynamic response was 18.1%, and the dynamic model could be used to analyze the vibration of an actual TBM. The vibration law of the testbed was close to the actual TBM, so the testbed could be used for the vibration law analysis of the actual TBM under other working conditions. The study of the vibration law under different working conditions and different digging parameters could be used to guide the intelligent tunneling of the TBM.