Long Span Structure Dynamics Analysis And Optimization Of Cruise Ship

Cruise ship,known as "five-star Hotel on the sea",is the top ship of shipbuilding industry with high difficulty,high technology and high added value.It is the jewel on the crown of shipbuilding industry.Long-span non-pillar structure(with only a few supporting structures in large area)is a typical structural feature of cruise ships,such as large theatres,restaurants,entertainment halls,playgrounds and modular residential area.The low stiffness characteristics of long-span structure lead to large structural deformation and vibration amplitude,and the design of ship hull vibration reduction is difficult.This is a problem of dynamic analysis and optimization design method for large-span structure of cruise ship.This paper has carried out in-depth research on this issue.Based on the design scheme of a medium-sized cruise ship,the vibration modal analysis of the typical hull structure is carried out.According to the vibration criterion requirements of cruise ship,the vibration response of typical structure of cruise ship under the vibration excitation of propeller and bow thruster is analyzed.Through the analysis of the vibration mode,natural frequency distribution and vibration response,vibration characteristics of medium-sized cruise ship are discussed.Lots of complicated modeling works are needed for the static and dynamic analysis of the long-span frame in cruise ship.To simplify the modeling works,by researching the multi-program collaborative method of NAPA software,MSC Patran and MSC Nastran software,using Visual Studio as the development tool,the design flow program based on those softwares is developed and availability is verified by Isight optimization software.With the program,parametric modeling and automatic analysis are achieved for model of cruise ship multilayer long-span frame structure.Thus,the program can rapidly obtain multi-scheme design results,improve the efficiency of design and analysis.The optimum design method of pillar topological layout in long span structures is studied.Based on theatre stand structure vibration response under bow thruster excitation,topology optimization base structure is established for pillar arrangement between ground floor and second floor stand in theatre area.Use SIMP method to establish the stand pillar arrangement topology optimization model considering structure mass as the objective function and velocity response of selected nodes as the constraint,and to carry out the dynamic topology optimization design.The analysis showed that with pillar layout optimization calculation method provided by this paper,it got a pillar arrangement plan with good vibration result.