Research On Wear Mechanism Of TBM Disc Cutter

Hard rock tunnel boring machine(TBM) is widely used in rock tunnel excavation due to its safety and high speed progress in tunneling. The working face of TBM is usually severe to the cutters, so cutter wear is extremely serious and leads to large cutter consume in TBM construction. Then it is of great importance to study cutter wear characteristics and predict cutter wear.In this paper, sliding abrasion test in dry friction condition was conducted on M-200 abrasion tester to simulate the disc cutter wear behavior. Then the wear morphology of the sampled was analyzed to obtain a further understanding of the mechanism of the disc cutter wear. The results show the relationship between distance and abrasive wear amount which is in agreement with former research. The influence of rock hardness, friction coefficient and lubrication on abrasion wear also analyzed in this test. The results indicate that cutter wear amount is positively correlation with rock hardness and friction coefficient; lubrication plays an important role in reducing wear. The test results also show that the wear mechanism will change and fatigue wear will happen if load is large enough. The influence of fatigue to cutter wear also is then studied qualitatively.A finite element model was then built to simulate the process of rock breaking by ABAQUS. Cutter sliding and cutter load distribution is obtained and the influence of cutter penetration and friction coefficient to cutter sliding is also studied based on the established model numerically. The results indicate that sliding distance is positively correlation with cutter penetration and negative correlation with friction coefficient. At the same time, load distribution of cutter was analyzed by the finite element model. The results show that the load distribution form is central concentrated which is basically the same as the conclusion of CSM model.Finally a new model to predict cutter wear of TBM is established which takes rock properties and operating parameters into account at the same time. The disc cutter wear of Dahuofang tunnel was then predicted to verify the new model. Predicted results is closed to actual cutter wear amount which verifies the accuracy of the prediction model. The new model may be utilized to TBM tunneling process.