Study On Joints Contact Characteristic And Dynamic Behavior Of Tunnel Boring Machine Under Uncertain Parameters

Tunnel Boring Machine(TBM)is a national important manufacturing equipment which combined with mechanical,electrical and hydraulic and it becomes the significant tool to tunneling.The deformation of joints under the huge propel force will change the kinetics of TBM systems which can lead to yaw even blocked the TBM.So it’s important to analyze the effects of the joints’ deformation in key position on TBM dynamic characteristic.This thesis keep an eye on the contact stiffness of the joints under propel force in TBM propel systems.According to fuzzy arithmetic,the uncertainty of clearance and loads on joints contact stiffness is discussed.On this basis,the kinetics equation is established to analyze the effect of joints deformation.This work is important to the TBM dynamics characteristic and this thesis includes the following parts.(1)Established the contact stiffness of jointsThere are two kinds of joints in TBM that are cylindrical joint and sphere joint.In this part,Hertz contact theory is used to analyze the stress distribution of the contact area and then established the relationship of force and deformation by integral the stress distribution.Making a comparison,the Winkler contact model is also used to analyze the contact stiffness when non-conformal contact assumption is not matched in Hertz contact model.Finally,a FEA model is established to verify the property of two kinds contact model.And result shows that Hertz contact model fits the FEA model better as the joints clearance grows.And that verify the Hertz contact theory is more accurate under the non-conformal contact.(2)Discussed the various characteristic of contact stiffness when parameters are uncertain.Influenced by manufacturing and wearing,the joint clearance and load will become some uncertain values which will has an impact on contact stiffness as to TBM dynamic characteristic.So Fuzzy Arithmetic is used to analyze the uncertain parameters’ effect on contact stiffness.The results shows that,clearance has a smaller effect on stiffness than load and the wave interval when clearance and load both uncertain are similar with the sum of each parameters uncertain.(3)Analyze of the effect of joints deformation on TBM headcutter position in tunneling procedure.According to the force characteristics,establish the TBM kinetic equations.And analyze the effect of joints in propel system on TBM headcutters.Finally,discussed the effect of joints deformation and its uncertainty on TBM in simply layer.The result shows when considering the deformation of joints,the TBM headcutter displacement has a bigger change compared with not considering joints deformation.That can help to predict the kinetic of TBM more precisely.