A nonlinear dynamics model of TBM with variable contact stiffnesses of the grippers and the hinges

Abstract

A lumped mass parameter model is established for the thrusting mechanical system of tunnel boring machines (TBM), in which the contact stiffness of TBM and surface of tunnel is considered. The nonlinear dynamics model is developed with the nonlinear contact behavior in the mechanical system and environment such as the interface between TBM and rock, and hinges and hydraulic cylinders based on the Newton-Euler equations. The natural frequencies and kinematic performance are discussed numerically. When TBMs excavate in the hard rocks, the effective thrusting forces decrease with the decrease of the angles between the cylinders and the mainbeam. The variable contact stiffness due to the complex geometrical structures has obviously influence on the dynamic performance, which should be considered in the precise prediction of the kinematic behavior.