Lightweight Design Of Ship Auxiliary Structures

Ship is an important means of water transportation.Reducing the weight of empty ship is one of the important means to improve the performance of ship and reduce fuel consumption.Ship auxiliary structure is used to support ship equipment and pipelines,that is,equipment foundation and pipeline support.Some large equipment foundations are over designed,which leads to over weight and some lightweight space.Due to the large number of pipeline supports,the weight reduction of a single support can also achieve a greater lightweight effect.In this paper,different types of foundations and pipeline supports are taken as the research object.According to different design constraints,such as stress,displacement and natural frequency,structural lightweight design is carried out under single or multiple working conditions,provides reference for lightweight design of auxiliary structures of ships.The main research contents and achievements are as follows:The ship rudder foundation was selected as the representative of large plate foundation,and the lightweight design method of this kind of foundation is explored.Firstly,the 2D plate element model of the foundation is established by using the finite element optimization software Altair Hyper Mesh,and the static analysis is carried out;secondly,by changing the type of the foundation,the integral foundation is changed to the column separated foundation;by using the software Altair optimization,the combination of size optimization and topology optimization is adopted,and the thickness of the plate foundation is taken as the design variable,and the stress is taken as the constraint to the column The results show that 37.7% of the weight of the separated foundation is reduced compared with that of the integral foundation,which provides a way for the lightweight design of the large plate foundation.Two typical lightweight design methods of fluid pipe support and exhaust pipe support are studied.Firstly,the light-weight idea of conventional fluid pipeline support is explored.The ship exhaust pipe support is selected as the representative of profile pipe support.The 1D beam element model of exhaust pipe support is established by using the finite element software Hyper Mesh for static analysis.The section parameters of 1D beam element are taken as the optimization design variables.The displacement at the expansion joint,the tensile stress and shear stress of exhaust pipe support and the first-order fixation of the support are taken With frequency as the design constraint,the lightweight optimization design of the exhaust pipe support is carried out,and the weight reduction effect is 45% lower than the original design,which provides a reference for the lightweight of 1D beam unit support considering both natural frequency constraint and stress constraint.The foundation of ship crane and its reinforced structure are selected as the representative of the foundation of plate beam structure,and the lightweight design method of this kind of structure is explored.The finite element model of crane foundation and its strengthened plate beam structure is established,and the mechanical property analysis is carried out.With the aid of dimension optimization,the structure lightweight optimization design of crane foundation and its strengthened structure under multiple working conditions is carried out.The result is 19.56% lighter than that of the original design,which provides ideas for the lightweight design of the foundation and its strengthened structure under multiple working conditions.According to the results of lightweight optimization design,the corresponding optimization design drawings are given to guide the actual ship design.The research content of this paper comes from the research topic of practical lightweight design technology of the Ministry of industry and information technology.