Study On Structural Strength Of Aluminum Alloy Stiffened Plate

Lightweight design is the trend of modern ship design.Because of its high specific strength,aluminum alloy is an ideal material for lightweight design of ship structures.However,the research on the structural strength of hull aluminum alloy is still very scarce at home and abroad,resulting in less application of aluminum alloy.As an important part of the hull structure,the stiffened plate is of great significance for the strength research.In order to master the buckling and fatigue strength performance of aluminum alloy stiffened plate structure,the buckling strength and fatigue strength performance of the stiffened plate structure supported by longitudinal beams through the bulkhead were obtained through the finite element analysis and experimental study.Based on the above research,aluminum alloy replacement design was carried out for the superstructure of a steel ship on the premise of satisfying the stiffness and strength,and then the yield,buckling and fatigue strength of the superstructure are studied respectively.The main contents of this paper are as follows:1)Nonlinear finite element method was applied to analyze the buckling sensitivity of aluminum alloy stiffened plate under the influence of grid size,model range,welding heat affected zone,initial geometric defects and residual stress.A set of finite element analysis method for buckling performance of aluminum alloy stiffened plate structure was formed;2)The buckling tests of aluminum alloy stiffened panels were carried out,and the ultimate bearing capacity of longitudinal stiffened panels with unilateral and bilateral stiffeners was obtained.The accuracy of the non-linear finite element analysis method was verified by comparing the experimental results with the above finite element calculation results;3)The fatigue tests of two typical welded joints and three longitudinal stiffened panels supported by different stiffeners were carried out.The probabilistic statistical method was used to process the test data,and the S-N curves of the corresponding structural joints were obtained;4)Based on the non-linear finite element method,the yield,buckling and fatigue strength of the superstructure of a steel ship were studied,which satisfies its stiffness and strength.The weight comparison between the aluminum alloy superstructure and the original steel superstructure on the premise of satisfying yield,buckling and fatigue strength was analyzed.