Study On Ultimate Strength And Failure Modes Of Typical Grillage Structures Of Large Cruise Ships

As the crown jewel of the shipbuilding industry,modern cruise liked a mobile hotel,with a wealth of entertainment facilities.Compared to traditional passenger ships,large cruise ships had plump superstructures,which require balance of stability and weight control.In order to control the weight and center of gravity of the superstructure,a large number of special structural forms were widely used in it.The safety evaluation of such special structures has become an important issue in the structural design of cruise ships.As for high-web grillages with opening,the existence of open holes will destroy the continuity of the structure and reduce the bending stiffness of the structure.However,the influence of opening on the failure mode of grillages structure had not been thoroughly studied,and the influence of opening size,location and opening form on the bearing characteristics of grillages structure was still unknown.The analysis of the ultimate bearing capacity and failure mode of these typical plate structures can provide guidance for the design of large cruise ship plate structuresThe prediction accuracy of the existing theory and empirical formula were limited,so it is necessary to carry out this part of the research.The evaluation method of the ultimate bearing capacity of the typical open-hole and high-web plate frames of large cruise ships is proposed,which can provide guidance for the preliminary design of cruise ship structures.Based on the above situation,this paper takes the typical grillage structure of large cruise ship as the research object,and proposes the bearing capacity evaluation method of typical stiffened panels and grillages structure of large cruise ships.The specific research work mainly includes the following aspects(1)The ultimate strength experiment of grillage under axial compression was carried out to explore the stress distribution and failure mode of the model,and the numerical calculation was carried out based on the 3D scanning results.The experimental results were compared with the numerical results to verify the accuracy of the numerical calculation method.(2)The nonlinear finite element method was used to calculate the stiffened panels with different flexibility intervals.The influence of stiffened parameters and deck parameters on the ultimate bearing capacity and failure mode of stiffened panels was discussed.A series of simulation work was carried out to obtain the prediction formula of ultimate strength of typical stiffened panels under different failure modes.(3)Taking the typical high-web grillages with opening as the research object.The influence of the geometrical characteristics of the girder,and the opening form and the opening size on the ultimate bearing capacity of the structures were discussed.The prediction method of ultimate bearing capacity of this structures was proposed by the numerical results.(4)The multi-layer grillage structure of large cruise ship was simplified,and the failure behavior of it under bending load was analyzed.The influence of lateral load,deck number and side opening on ultimate strength and failure mode of structure was investigated.The scheme of replacing superstructure with aluminum alloy is analyzed,which can provide suggestions for the lightweight design of superstructure of large cruise ship.