Dynamic Analysis Of TBM Cutterhead Based On ANSYS

Using ANSYS, the author performed modal analysis, harmonic analysis, transient analysis when started and steady-state analysis in stable operation of tunnel boring machine(TBM) cutterhead. Some results were acquired which might be valuable for tunnel engineering. Some beneficial advices were proposed for the operation of TBM cutterhead safely, stable and with slight-vibration. A set of methods were put forward for design, improvement and optimization of TBM cutterhead. The main work in this paper includes:1.Modal analysis of cutterheads with and without ribs was performed. The first six natural frequencies and the corresponding modals of two types cutterheads were obtained. The lower natural frequencies of the cutterheads are obviously increased by the presence of ribs. For lower modals the patterns of modal of cutterhead with ribs are much similar to those without ribs. However, for higher modals, the displacement of cutterhead without ribs is mainly located on the cutterhead surface whereas those of cutterhead with ribs are moved to its ribs.2.Harmonic analysis of cutterheads with and without ribs was conducted. The amplitude-frequency curves of all points on the cutterhead were draw under the impact of periodic harmonic excitation. The results revealed that although the addition of ribs may effectively reduce the vibration of the cutterhead, at certain frequency it may also induce vibration stronger than that in absence of ribs. The resonance frequency of cutterhead with ribs has a more focused range, whereas that of cutterhead without ribs is more scattered.3.Transient analysis of a cutterhead when started was performed. The responses of the displacement, velocity and acceleration of all points on the cutterhead were obtained. The curves of displacement, velocity and acceleration were draw at central disc、face disc and edge disc when the cutting depth is 5 mm, 9 mm and 11 mm respectively. The impact of UCS(uniaxial compressive strength) of rock on the dynamic response of the cutterhead was analyzed.4.Steady-state analysis of a normally-working TBM cutterhead was conducted. The responsive curves of displacement, velocity and acceleration of all points on the cutterhead were shown. The varying patterns of displacement at three different positions on the cutterhead with different cut depths were compared. The data are of value for choosing the optimal cut depth.