Studies On The Structural Strength Analysis And Optimization For 500m~3/h Cutter Suction Dredger

The waters of the Heilongjiang River are important distributing centers for trade at China' s northeast border. The rapid development of border trade propels the gradually increasing of tonnage. However, channel siltation condition limits the traffic capacity of large-sized vessels, which produces negative effects on water transporting economy. A cutter suction dredger is an engineering ship used most in the dredging engineer field.Compared with other engineering ships, it possesses the advantages of low cost and wide adaptive range. Meanwhile,it plays an important role in ensuring waterway transport in safety and smooth flow.The form of a cutter suction dredger is rather special with a broad hull and a shallow draft. Its force condition is complicated in navigation and work. Under the action of waves,a bigger stress concentration is produced easily on the hull. It is necessary to conduct a strength checking. A bridge is one of the most important equipment for a dredger. Its structure is cantilever beam. The whole of that lies under the water when working. It works in bad conditions and its force conditions are complex.Based on the actual situation of Heilongjiang waterway and the developing situation of cutter suction dredgers, this thesis chooses the 500m3 /h cutter suction dredger that works in the waters of the Heilongjiang River as its research object. This subject applies MSC.Patran finite element analysis software to study the structural strength of the whole dredger and its special dredging plant bridge, and then utilizes the orthogonal experiment method to optimize the structure of the bridge. Firstly, the finite element model of the whole ship is built, static and wave loads are applied to it, and then the two conditions, dispatching and working conditions, are analyzed. The stress concentration area of the hull is obtained by calculating and the causes of the stress concentration phenomenon are analyzed.Sequentially, this subject finds out the location of maximum stress and compares it with the allowable stress. In the meantime, calculation of the displacement is taken out for the comparison with the standard. Secondly, the subject sets up an overall model of the bridge,analyzing as well as calculating the vertical load and lateral load in both horizontal suspension status and working condition. Then the loads are applied to the model and the results obtained are compared with the specification requirements. The findings showed that the stress and strain are both much smaller than the specification. In allusion to the results,adopting conventional theoretical optimization method and the orthogonal experiment method carries out the structural optimization to achieve economic optimization on the condition that all the requirements are satisfied. According to comparing between the two optimization methods, the subject finds the proper effective method for the structural optimization of the bridge.