Research And Design On Six-DOF Tunnel Segment Erector Based On Virtual Prototype Technology

Shield machine is a kind of Tunnel Boring Machine, Which is large high-tech engineering construction equipment devoted to the excavation of the underground passage. It has many advantages,such as digging fast, quality, security, economic, environmental protection and low labor intensity. Its advantages are overwhelming,comparing to the traditional method. Tt will occupy the dominant position of construction method for underground tunnel. With the arrival of the new millennium,Its demand will continue to increase.Currently,the core technologies of the TBM have been grasped by some foreign manufacturers such as Mitsubishi Heavy Industries and Kawasaki Heavy Industries,Herrenknecht,Robbins.Therefore, the development of integration technology of shield machine in China will not only bring great benefit to the development of the manufacturing sector, but also save a lot of foreign exchange for country. Shield construction operations include excavation, boring, supporting and deslagging . Supporting operation is one of its key operations, which bears the rock pressure and hydraulic load to ensure that the design size of the tunnel. Supporting operations including two step. The first step usually use the prefabricating segment. The segments which is poured with concrete are assembled into the design circle by segment erector.While the machine is working, the cyllindrical jacks act on the former segment circle. The shield will stop excavate when it advances one segment width.Then the next segment circle will be assembled. Therefore, the quality and efficiency of the segment circle assembling will be directly impact on the quality and progress of the whole project.So we need the excellent segment erector. Currently, many domestic enterprises and universities have developed their own segment erector. They have different performance characteristics. However, they have prevailing shortcomings that they can't well achieve the six degree-of-freedom movement.Some need supporting facilities to emendate the segment location.Some require more complicated operation to repeatedly adjust. All these affect the efficiency and quality of segment assembling.In this paper, I design a new six degree-of-freedom segment erector using modern design theory and method which Based on a triune new products design platform including design, simulation and components intensity verification.The design platform consists of SolidWorks ,ADAMS and ANSYS.Now the main content and research methods are described below:1. First , I researched modern design theory and method and consider Virtual Prototyping design technology is a practical and effective design method. Systematic introduced the theories of the large-scale commercial finiteelement software ANSYS.Detailed introduced the calculating thinking and problem solving steps of the finite element method; systematic introduced themulti-body system dynamic of ADAMS.Detailed introduced the establishment of the Lagrange equation of the multi-body dynamic and the various ways to solve it.2. Carried through a In-depth study of the processes of segment assembling.Detailed studied of the six degree-of-freedom movement. Namely, translation, rotation, movements, pitch, roll and deflection. Identified the functional requirements and project design parameters of segment erector. Brought forward my design project on the basis of comparative analysis of the domestic and foreign segment erector design ideas. Implementating bodies for 6-DOF campaign were identified respectively. Layout of the erector used symmetrical double-arm. Translation telescopic action of two cylinder achieves the translational motion. The gear transmission achieves rotary movement. Translation telescopic action of two cylinder achieves the stretching motion. The characteristics of fine-tuning motion are high precision of motion control and small range. A new 3-DOF parallel manipulator with 3-rotation is synthesized and investigated.The parallel manipulator constituted the skeleton of Fine-tuning structure. To gain a better understanding of the mechanisms, a methodology for analyzing the kinematics of such manipulators is presented.Studied the Locking agencies. Identified the locking means.It is maked up of an locking cylinder and five short columns.3. Performed a preliminary calculation for the the main design Size. Completed The detailed design of mechanical structures based on the CAD platform SolidWorks. And then built up its assembly model of virtual prototyping. Proformed interference inspection and Identified the design system size meet the requirements of layout.4. Researched the data transfer between CAD and CAE software.Transfered the solid Model to the mechanical system dynamic analysis software ADAMS. Simplified the model reasonably and added various constraints. Specified the motion function for the system based on the the step time planning of the technology for segment circle assemblied.That is the simulation prototype. Performed the kinematics and dynamics simulation on the prototype under variety work conditions. The results of simulation show that the design has six degrees of freedom movement capacity. At the same time we can get the subjects of various components and the dynamic characteristics of the drive components, provide boundary conditions for strength checking and provide a basis for the power system design.5. Performed a special simulation study on fine-tuning mechanism. Discussed the kinematics analysis based on Virtual Prototyping and perform parametric design for it.Provided test Platform for control system design.6. Studied the dangerous condition of the system. FEM analysis of key components of the segment erector were carried out under the boundary conditions from dynamic simulation based on finite element analysis software ANSYS.Provided the basis for design modify.The innovation point of this design is that satisfactorily resolve the structural design of the fine-tuning of the segment erector by using a 3-DOF parallel manipulator. Fine-tuning institutions have relatively small layout space. More relatively actions that it must be completed, and it endures large relatively load. Using ordinary institutions in series will get complicated structure. The strength of the component and stiffnessof the system is difficult to guarantee. Problem is resolved by using this parallel institutions.This new segment erector possesses compact structure, reasonable layout and good dynamic performance. It can act complete six degree-of-freedom movement and can achieve a high degree of automation.It has better capability compared with domestic similar product.