Numerical And Experimental Study On Ultimate Strength Of Stiffened Plates Under Combined Loads

The ship is subjected to complex loads such as wind and waves,cargo,etc.during the voyage.The hull may undergo deformation such as bending and torsion.The stiffened plate,which is the basic mechanism of the hull,will be subject to combined loads including axial compression / tension force,bending moment in the plate,shear force,and lateral pressure.Therefore,the ultimate strength of stiffened plates under combined loads needs to be studied.In this paper,the structure of the stiffened plate on the bottom of a 10,000 TEU container ship is studied,and the ultimate strength of the stiffened plate under combined loads is analyzed by nonlinear finite element analysis and experimental research.The ultimate strength of stiffened plates is studied from the model range,grid size,initial defects,boundary conditions and loading methods by FEM.And a set of mature and complete calculation methods are formed.Based on this,a series of non-linear finite element calculations were performed for the ultimate strength of stiffened plates under different load proportions,and the envelope curves of the longitudinal ultimate strength and the transverse ultimate strength were obtained using the calculation results.The results show that the longitudinal ultimate strength decreases with the increase of transverse load.With the increase of lateral load,the ultimate strength of stiffened plate decreases gradually.Under in-plane load or small lateral load,most of the stiffeners and plates yield in compression.When the lateral load is gradually increased,the compression failure of the plate and the tensile yield of the stiffeners together lead to the collapse of the stiffened plate.The ultimate strength test under the combined load was designed,and the model design,loading scheme design and initial defect measurement were completed.After that,the ultimate strength test of the stiffened plate was completed.The measured initial deformation was added to the model for numerical simulation calculation.The test results are processed and discussed,and compared with numerical calculations.The nonlinear finite element calculation results are close to the ultimate strength values obtained from the tests.The experimental and numerical results show that the lateral pressure and transverse load have influence on the ultimate strength of the stiffened plate.But the small lateral pressure and transverse load are not significantly reduce the ultimate loadcarrying capacity of stiffened plates.