Rational Design And Optimization Study On Midship Section Structures Of Large Submarine Cargo Vessel

The trend of obedience to the South China Sea strategy,design and development of dual-use large submarine cargo vessel is slow,and the complexity of its multi loading conditions have greatly increased the overall R&D difficulty.As an important part of ship research on hull performance,structure design of large submarine cargo vessel is the main work presently.The midship section structure among the structure of the hull plays an important role both in the total weight or longitudinal strength.Its rational design is always the primary problem for structure designers.Therefore,this paper will take the midship section structure of large submarine cargo vessel as the research object,which will take some research on some key technologies of hull structure rational design and local structure optimization based on satisfying the basic structural strength and reliability,and has good dynamic characteristics with steel material saving.The main research contents of this paper are as follows:(1)Preliminary design of midship section structure: Considering multi loading cases,to determine the equivalent plate thickness based on neutral axis interpolation method and equivalent thickness method.Then conduct material distribution on each plate according to the structural strength and stability of each component,include the plate thickness,longitudinal dimension,longitudinal spacing and rib plate spacing.(2)Optimization design of midship longitudinal structure: In consideration of equivalent stress constraints,taking the minimum design weight of the longitudinal structure as the objective function,then the dimension optimization design of midship longitudinal structures was carried out based on theoretical analysis method and finite element method respectively with the application of structure sensitivity analysis.(3)Topology optimization design of transverse frame structure: With the introduction of topology optimization algorithm under multi loadings,using Sub-Model and Three-Cabin Model technologies to solve the internal girder layout and hole problems of the transverse frame respectively,which reaches the minimum of structure weight while meets the supporting function of longitudinal structure and the self transverse strength.(4)Give the experience design manual for the same midship section structure,including longitudinal structure layout and longitudinal-transverse structure design.Meanwhile,the topology optimization research was carried out about hole design and stiffener layout problems involving the transverse "floors" structure and typical grillage structures under static-dynamic characteristics(frequency and stress)and dynamic response constraints(dynamic displacement and velocity),which provides some references for the detailed design of the whole ship structure.