Structural Optimization For Transverse Frames Of SWATH

Because of the weight of structure takes up a high percentage of the light ship weight,the structural optimization for SWATH is more important than mono-hull ship.Firstly,this paper introduces the concept of structural topology optimization,shape optimization,size optimization and full stress design.Looks back the development process of optimize algorithms.introduces the optimize algorithms and implementation of MSC/NASTRAN,states the mathematical expression of the general structural optimization and the physical expression of topology optimization.Then taking a cabin FEM model as the study object,using the optimize algorithms of NASTRAN,this paper carries out topology,shape and size optimization for the transverse structure to maximize the overall stiffness of the cabin structure.After all the optimizations,this paper abstracts a final optimized design which satisfies series engineering requirement.Finally,using DNV/SESAM program,this paper carries out the finite element analysis to verifying the improvement of structure response of the optimized design.By optimizations and analysis,this paper finds a optimize form of the transverse structure of SWATH,which reduces the overall displacement in transverse bending moment by 20.5 percents,reduces the maximal stress of transverse bulkheed plate by 33.3 percents.The weight of the optimize form of the transverse structure increases just 4 tons.