Disc Cutter Cutting Force Influencing Factors And Roller Blade Shape Optimization Of The Design Study

With the need of rapid excavation of underground engineering and improving the science and technology level, shield machine construction technology has been rapid application and development in China. The development of shield machine application and construction of underground space engineering have induced the growing attention of related government departments and businesses to the investment in the employment of shield machine in the underground tunnel projects.Disc cutter is an important tool of shield machine to crush the rock during excavating tunnel, cracking efficiency of it directly impacts on the construction efficiency. To date, the research on the rock breaking properties of disc cutters of shield machine, compared with foreign countries, is still in its initial stage. Based on wide reading and in-depth study of the related articles and books centering on the rock breaking theory, through research on failure criteria of rock medium under breaking process of disc cutter, it can lay a theoretical foundation for further comprehensive research rock breaking mechanism. Study on cutting property of disc cutter, it also can provide theoretical basis for structure improvement of disc cutter and cutter optimal layout on shield cutter head, at last, achieve our research objective of improving crushing efficiency. The main contents fall into such parts as follows:Based on the systematic study of the existed rock constitutive model achievements and introduction of rock breaking mechanism, main failure mode of rock in the breaking process of disc cutter is added and revised in order to meet the actual situation.The method of establishing finite element model of disc cutter breaking process using ANSYS/LS-DYNA software is introduced. Through dynamic simulation we can obtain that geotechnical interface disturbance insulted by disc cutter as well as force size in the disc cutter. Based on plenty of experiments, it confirms reliability of numerical methods and provides a method to study cutting performance for different geological conditions.Based on a large number of single-factor cutting simulation, the influence of many cutting conditions such a blade angle, blade width, over-arc radius, cutting depth and cutting speed on cutting property are discussed. Subsequently, use of interactive multi-factor orthogonal test method, impact of significant factor during the breaking process has been obtained.Optimization model has been built based on structural parameters as design variables, specific energy consumption as objective function. Combined with whole disc-shaped arrangement on specific shield in the engineering research, with making use of genetic optimization design theory. At last, we have obtained the optimal structure of parameter values for different rock materials, which offers the gist for construction of the practical shield.