Analysis Of Cutting Mechanism And Multi-objective Optimization Design Of Shield Tool

Shield machine is a large mechanical device, which in the integration of a variety of technology such as mechanical, electrical, hydraulic, control, ground and so on.Cutter and cutter head are the key components of shield machine, which are directly contact with the soil and used to complete excavating and supporting the soil of working face. Because of cutting frequent, cutters are easy to wear failure.So far,design of cutters' adaptability of geology is a lack of Complete theoretical basis,empirical data and reliable reports of experiment analyzes, Study on reliability and life of the cutter is still in the initial stage. Although the CAE technology has been widely used in cutter design work, but the effectiveness of computational model has become the important problem of the digital design field. Therefore, dependent on the extensive research and analysis the related problems, we design and produce the model Shield machine, using Euler Lagrange coupling(CEL) method study the theory of cutting and influence factors, Genetic Algorithm is used to optimize the model built based on structural parameters of disc cutter. The main researches of this paper can be summarized as follows:(1) Based on the technical requirements and index of shield tunneling, design and produce the earth pressure balance shield.(2) Using Newton's law analyze the cutting mechanism of rock, establish a mathematics model of the cutting force.(3) Based on CEL, the three-dimensional simulation model for soil cutting process was established by using Drucker-Prager constitutive model and the results of test validate the effectiveness and accuracy of the model.(4) The method of establishing finite element model of cutter breaking process using CEL method, Through dynamic simulation we can obtain the main influence factors of cutter's force, great impact factors are blade angle, cutter radius and cutting deep, Little effect of cutting speed. Disc cutter blade width increase cause the cutting force increases, blade angle and cutter radius with the same effect. Disc cutter' speed make small influence on cutting force as well as cutter. The more rock the disc cutter break the more wear received.(5) Genetic Algorithm is used to optimize the model built based on structural parameters of disc cutter as abrasion loss and bearing force as objective function. theoptimal value of the structural parameters is obtained under 17 inch disc cutter and red sandstone, reduce the bearing load and the amount of wear. The result indicates that the optimization model of structural parameters of disc cutter and the Genetic Algorithm to solve this model are both feasible and effective.