| Since the beginning of the new century,China has achieved good development momentum.Underground space has become one of the main battlefields in all walks of life,as well as an indispensable part of the urbanization construction and many major national livelihood projects.Therefore,as the large-scale special equipment for tunnel construction,Tunnel Boring Machine(TBM)has also been paid more and more attention and developed.The disc cutter is the part of TBM that contacts with rock directly,and it is also one of the essential components of TBM.The performance and service life of cutter directly affect the quality and cost of the project.By observing the working site of disc cutters on the spot,referring to a large number of domestic and foreign literatures in related fields,and starting from the stress of disc cutter in rock breaking process,this paper discusses the factors affecting the service life and construction effect of disc cutter,and reveals the stress law of disc cutter in rock breaking process.It is helpful to improve the rock breaking effect and prolong the service life of the cutter.The main research work of this paper is as follows:(1)The background and significance of research on rock breaking theory and force of the disc cutter are summarized.The development of TBM is summarized.The research status of disc cutter is also described,including the research on force,simulation and wear of disc cutter etc;(2)The properties of rock and engineering rock mass are briefly described,and the mechanism of rock fragmentation is analyzed.This paper summarizes the structure,composition and classification of disc cutter,analyses the stress distribution in the process of rock breaking by disc cutter,and summarizes the rock breaking mechanism of disc cutter;(3)Based on the force condition of the disc cutter in rock breaking process,the existing force prediction models of disc cutter are deeply studied.The advantages and shortcomings of existing models are analyzed.Finally,the influence of important parameters(cutting speed,penetration and tool spacing)on rock-breaking force is quantitatively analyzed by force prediction models,and a model is selected as the basis to verify the rock-breaking force of cutter;(4)With the help of CATIA and ABAQUS,the finite element analysis model of rock breaking of disc cutter under service condition is established,and the rock breaking simulation research is carried out.The actual force curves and datas are obtained,the numerical range of rock breaking force under given parameters and the order of influence of rock-breaking parameters of cutters on rock-breaking force are obtained.;(5)ABAQUS is used to analyze the working temperature and thermal stress inside the cutter ring in the process of rock breaking by disc cutter.The law of temperature and stress distribution inside the cutter is understood,and the cause of disc cutter damage is further revealed.Through the research of this paper,the law of force variation during rock breaking process of disc cutter is obtained,and the influence of relevant parameters on the force of cutter is determined,and the variation and distribution of temperature and stress in the process of rock breaking of cutters are obtained,which provides a basis for optimizing the structure of disc cutters,reducing the probability of abnormal damage of cutters and prolonging the service life of cutters. |
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