Research On Performance Of TBM Gripping-Thrusting-Regripping Mechanism

Tunnel boring machine(TBM)is a complex construction equipment which is integrated with excavation,tunnel system installation and online steering.The gripping-thrusting-regripping mechanism is the core transmission part of TBM to complete the efficient and precise excavation process.Its performance directly affects efficiency,accuracy and dynamic characteristics of TBM.It is of important strategic meaning to study the key technologies and improve independent innovation design capability of the gripping-thrusting-regripping mechanism.Based on the above engineering application backgrounds and National Basic Research Program(973 Program)of China and National High-tech Research Program(863 Program)of China,this paper successively studies topology configuration,kinematic characteristic and FEM in order to provide a theoretical basis for mechanical design of TBM gripping-thrusting-regripping mechanism.Chapters are organized as follows.Chapter 1 provides an overview of the TBM and expounds the research purpose and research significance of the topic.The industry and current studies were introduced in detail.The last research items of this paper,topology configuration,kinematic characteristic and static characteristic of TBM gripping-thrustingregripping mechanism,were introduced.Chapter 2,taking the gripping-thrusting-regripping mechanism of open TBM whose cutterhead diameter is 8m as the research object,structure composition and working principle of the gripping-thrusting-regripping mechanism were introduced in detail.On this basis,the DOF of the mechanism components under different working conditions were computed with the G-K formulas.The influences of the mechanism topology configuration upon engine performance system were systematically analyzed under different conditions.The design criteria of the mechanism topology configuration were established.Chapter 3,taking the test bench of open TBM gripping-thrusting-regripping mechanism as the research object,scaled parameters,gripping-thrusting-regripping mechanism,simulator of surrounding rocks,load simulator and support device of the test bench were introduced in detail.On this basis,kinematic equations of the mechanism under different working conditions and programming model of the correction track were established.The research contents establish kinematics fundamentals for finite element modeling of TBM and provide an effective calculation method for the gripping-thrusting-regripping mechanism precision online steering and correction track.Chapter 4,in samcef environment,a modeling method of the FEM fast reconstruction of different configurations was studied.The modeling method that has generality can realize modularization of modeling process and effectively improve calculation efficiency.The modeling method mainly includes modular division method,joint surface modeling,analysis of inverse positional and load analysis.On this basis,taking the test bench of open TBM gripping-thrusting-regripping mechanism as the research object,driving cylinders of the mechanism relationship with load under different working conditions were analyzed in detail.Chapter 5 gives the conclusions and discussions on future works.