Finite Element Simulation Of Gripping-Thrusting-Regripping Mechanism And Optimization Of The Main Beam Based On SAMCEF^TM

This paper studies the simulation problem of tunnel boring machine and optimizes the key structural components.An open type TBM,whose diameter is 8040 m with horizontal support,is taken as an example.First analyses the gripping-thrusting-regripping mechanism motion method and topological structure.Using SAMCEF finite element simulation platform,elaborates the finite element modeling method of TBM.According to the different loading conditions of different working process,simulates and analyses the static problems of TBM under straight driving,adjusting and partial working condition.Finally,to solve the excessive material waste problem of key structures optimizes the main beam.Full text contents and main conclusions are summarized as follows:Firstly,taking horizontal single support open type TBM as an example,analyses the advantages and disadvantages of different types TBM,elaborates the structural components and working principle of cutter head and GTR mechanism respectively.Furthermore,the different topological structures are confirmed by analyzing different motion types.Secondly,establishes the TBM 3-D geometry model and imports into SAMCEF.To build the finite element model,the structure is divided into key structure modeling,joints modeling and interface modeling.The modeling method of hydraulic cylinders,slider-guides,main joints and interface are discussed in details.Thirdly,simulates the straight driving process,the adjusting process and the partial load process,and then analyses the simulation results of mechanism and main beam,especially on stress and displacement distribution characteristics.At last,discusses the influence of loads,joints stiffness and position on the main beam static simulation results.Finally,analysis shows that the stress of main beam is much less than the maximum allowable stress.To solve the material waste problem,based on the APDL language,studies the main beam section optimization and topological optimization.According to the results,the main beam is thinned and added force transfer ribs.The new type main beam structure is better than the old one,and the studies provide a reference for the main beam structural design.