Research On Wear Life Prediction Model And Numerical Simulation Of Disc Cutter On Shield Machine

While the shield tunneling method is widely used, as the disc cutter is the main part of rock breaking, the wear problem has become the key factor which restricts the quality and efficiency of shield construction. On the basis of consulting a large amount of literature at home and abroad and combining engineering problems we regard the wear and life prediction model of disc cutter as the key problem to be solved. At the same time, the influence of the disc cutter on the rock breaking effect is studied. As while as the multi objective optimization model with smaller energy consumption, smaller volume wear, longer distance from the single time to the changing of the cutter, and faster driving speed, longer distance driving and faster tunnelling. The main researches are as follows:1. Counting the failure types of the disc cutter and the number of each type in the project, the failure mode of the disc cutter is analyzed and summarized. Based on reliability theory-failure mode and the method of risk analysis, the different failure modes of the disc cutter and its corresponding effect of damage are given and the wear mechanism of the disc cutter is analyzed. By using the classical theory of tribology derived abrasive wear model and the construction data record of disc cutter wear on the removal of plastic, brittle fracture, fatigue wear mechanism accounts for the proportion are determined.2. Based on the analysis of the stress on the disc cutter, the appropriate stress model was selected. Using matrix transformation method, the equations of motion of a point which on the front side and side of the disc cutter are set up. Based on the classical tribology theory and the wear mechanism of disc cutter, the disc cutter force model and motion equation are importing wear and fatigue wear mode. Then the prediction model of the front and side wear of the disc cutter is established, the prediction model of the disc cutter life is also obtained. By using Matlab programming, the relationship between the radius, the width and the angle of the cutting edge of the cutter is obtained. The driving distance with the numerical relationship of rock compressive strength, shield penetration, the radius of the installation relationship are gotten, and the predicted value is compared with the construction record data.3. Using ANSYS/LS-DYNA, according to different installation radius, different shield penetration, simulation of rock breaking force on 18in widen disc cutter, rock breaking process are analysised. the rock breaking force is obtained by simulation and the rock breaking ratio can be calculated.4. According to wear problems in the process of sand gravel, sandstone and mudstone formation, some reasonable suggestions on increasing the service life of the disc cutter are put forward. The high efficiency of rock breaking efficiency (low energy consumption) was established by considering multi constraints, a one-time replacement of the disc cutter to be able to dig longer distance (unit driving distance wear is small), multi objective optimization model for fast driving speed, and the optimization of the energy consumption of broken rock broken rock is given. As while as driving distance, driving speed and the corresponding optimal penetration, cutter spacing though changing the cutting tool only once.