Analysis And Optimization Of Structural Strength And Dynamic Response For Self-propelled Cutter Suction Dredger

The structural features of self-propulsion cutter suction dredger are different fromother conventional ships as there are slots in both the bow and the stern to set thebridge and spud. These slots cause the big openings on the deck. The complexequipment, especially the bridge structure, will couple with the body. The structuralstrength, deformation and the characteristic of vibration will be different from theconventional ships because of the big opening on the deck and the equipment on theship. The variety of dynamic performances are difficult to meet for the whole ship,especially the dynamic response performance; or the design requirements are meet,but it’s unreasonable and uneconomical in terms of structure and material. Byestablishing the FEM model of the self-propulsion cutter suction dredger (includingthe superstructure) and the bridge structure and taking the coupling of the bridge intoconsideration, the analysis and the research of the structural strength and thecharacteristic of overall vibration under service and working conditions have beendone. And eventually the structural dynamic response optimization for the whole shipwas studied by using the forefront of issues in the field of engineering structuraldesign of structural dynamic optimal design method. The following work has beendone in order to provide reference and basis for the design of this type of ship.(1) The evaluation for the structural strength and vibration characteristics. Byestablishing the FEM model of the self-propulsion cutter suction dredger(including the superstructure), the analysis and the research of the structuralstrength and the characteristic of overall vibration under service and workingconditions have been done. In this process, the calculation and the loading methodof the complex load for the self-propulsion cutter suction dredger were studied.(2) The dynamic response forecast for the whole ship. The modes of vibration wereanalysed. The effect of the bridge structure was considered. The dynamic response of the whole ship under service and working conditions were calculated based onthe modal analysis results. The results were compared.(3) The sensitivity analysis of the design variables for the whole ship. The sensitivityanalysis was done by taking the thickness of the plate and the specification of thesection bar as the design variables. The design variables were screened based onthe result of the sensitivity study.(4) The dynamic response optimization study for the whole ship. The minimum of themass was the objective function. The stress, displacement, natural mode and thedynamic response result were the constraint condition. The dynamic responseoptimization study was done by establishing the optimization model in iSIGHT.