Study On The Wear Mechanism And Life Cycle Of Disc Cutter And Cutter Held Of TBM

TBM is a representative product in equipment manufacturing industry. The disc cutter is the main tool to break rock on the cutterhead. The condition of the disc cutter is bad and it is the main tool to break rock belonging to vulnerable parts and key parts of TBM. According to the statistics, the time to detection, replacement and maintenance of the cutters accounts for about 1/3 of the construction period; the cost of the cutters accounts for about 1/3 of the cost of the whole project. What’s more, rock breaking models, wear models and life system research can provide theoretical basis of tool changing, which has guiding significance for shield design and is key for shield cutter research.Rock breaking mechanism is the prerequisite to accurately predict the performance of the disc cutters and the performance prediction is the key for TBM design. Wear mechanism research is the prerequisite of cutter life prediction and the cutter life prediction is the theoretical basis of tool changing. Therefore, the main research contents include the following parts:(1)The rock breaking mechanism for hard rock is verified by deeply analyzing the interaction between surrounding rock and knife ring in the process of breaking rock, and the three-dimensional equations of disc cutter rock breaking point based on construction parameters are established. The stress distribution function after surrounding rock is compressed is verified and the performance model is constructed applying micro-elemet integration. The performance prediction model of the disc cutter is fixed applying Coulomb-Mohr criterion to meet the real condition.(2) The rock breaking mechanism of disc cutter is deeply analyzed to verify the knife ring wearing mechanism of the interaction between the disc cutter and surrounding rock. The influencing factors of the disc cutter, rock and process parameters are analyzed, and the factors influncing the wear rate is discussed, and the wear conditions are classified.(3)The low of radius decreases of the disc cutter is deeply analyzed to study the knife ring wear rate and the calculation formula of the wear loss is defined. Meanwhile, the corrosive influncing factors of the surrounding rock is deeply analyzed by setting the CAI value as the corrosive yardstick. The relative analyze can be implemented with the wear coefficient of the knife ring. Therefore, the life prediction model of the disc cutter based on CAI value is established by the regression analysis.(4)By designing the rock breaking experiment with single factor of TBM, the correction and applicability can be verified. By designing the orthogonal rock breaking experiment with three factors and three levels, the major and minor relationship can be verified. Meanwhile, the wear coefficient table of the disc cutter can be obtained by designing the knife ring wear experiment, which will be basis for establishing the life prediction model. The correction and applicability can be verified by the data of Qin Ling export tunnel based on CAI value.