Numerical Simulation For Soil Cutting Process And Calculation Method Of Cutter Head Torque Of Shield Machine

Shield machine, a large mechanical device, has been widely used in tunnel engineering such as transportation, city infrastructure, mining and water conservancy due to its advantages of building speediness, environment protection and less effect to surrounding etc. 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. The adaptation of structure parameters, operating parameters of shield machine and geological conditions in different cities exert different influence on the cutting force variation and cutter head torque of shield machine. So studying and predicting the cutting force model and the calculation method of cutter head torque have always been the key research subjects in engineering. In order to investigate cutting mechanics problem of shield cutter and to design the drive system of cutter head, the load state of shield cutter and the calculation model of cutter head torque were analyzed based on comprehensive analysis of interaction between cutter and cutter head and soil. And this provides theoretical basis for design, manufacture and the using of shield machine.Based on ABAQUS, the three-dimensional simulation model for soil cutting process was established by using Drucker-Prager constitutive model and shear damage criterion with element deletion function. The whole process of soil cutting and the variation rules of cutting force under different geological conditions were analyzed. According to the soil mechanics theoiy, the failure model of soil cutting process was analyzed and then a mathematics model of the cutting force was established. The formulas for calculating draft force and vertical force of cutter were formed.The calculation model of cutter head torque was proposed based on systematic analysis of influential factors. Formulas of calculating cutter head torque components were deduced by using the soil mechanics theory and tribological theory. And the validity of these formulas were proven by using an instance to show the correctness of the proposed model.