Analysis Of Rock Cutting For Large-sized Cutter Suction Dredger

Rock dredging is a new development in dredging industry. Nowadays the increasing dredging demands and more complicated dredging objects are drawing more people's attention to rock dredging than ever before. In recent years, with more and more projects of dredging rock been conducted, varies fresh problems and challenges are emerging, urgently requiring related theoretical and practical research for guidance and solution.The cutter head plays a key role in the rock dredging process, which makes it the hot spots of the correlated theoretical research. As regard to the research of cutter head, the forces on it during the dredging are the most significant factors that deserve consideration. The cutter forces not only influence the wear of cutting tools directly, but also are the main design basis for the cutter suction dredger and cutter head. Meanwhile, the analysis of forces on cutter head is prerequisite of the research of other equipment on dredger.For the better analysis of forces on rock cutter head, the thesis firstly investigated in the components, structures and working principles of cutter suction dredger and cutter head, and reviewed the development of the large cutter suction dredger for rock dredging, furthermore, the characteristics of the cutting object the rock were introduced. Secondly, based on the achievement made in the field of coal cutting research, and considering the features of rock cutting by cutter head, the forces on cutter tooth were analyzed from the view of statics, which brought out the equations of static equilibrium for the forces. After that, the equations were developed by employing related experience into applicable mathematical model for calculating the cutter forces, and model parameters, which influence the forces dramatically, were discussed in detail. Thirdly, the mathematical model was adopted to calculate the forces and power of the cutter head equipped on a 4200kW large cutter suction dredger, and the relations between forces and power of cutter head and the cutting speed, swing velocity and other working parameters were discussed. Besides the theoretical research on the cutter head, the data from in-situ experiment of dredging rock by the 4200 kW large cutter suction dredger were collected, which presented the variation of the cutter power, swing velocity and the rotation rate of cutter head. Meanwhile, by applying the field data to the mathematical model, the comparison were made between actual results and numerical results, verifying the validity of the theory raised by this thesis. In the end, based on the theoretical and practical research, independent software were programmed using Visual Basic language, which would facilitate further study and practical application in future.