Stiffness modeling of thrust cylinder in hardrock tunnel boring machine

摘要

The thrust system of TBM propels the cutter head boiling forward and the strong impulse loads on propelling cylinder cause serious vibration problems. Based on the typical thrust system which the thrust cylinders are controlled by pressure reducing valves, the paper obtained the dynamic velocity stiffness, static velocity stiffness, minimum velocity stiffness of the thrust cylinder. According to the frequency distribution of dynamic velocity stiffness, it was concluded that load damping directly affect the static velocity stiffness. In middle frequency range, because of the oscillation order, there is a attenuation, which need to be compensated in the stiffness design; otherwise in high frequency range, velocity stiffness can be simplified into a first-order differential element. It can also be ascertained that the static velocity stiffness decides the break frequency. Simulation results verify the conclusions above.