Nonlinear Similarity Criteria Of Buckling Process Of Stiffener Plate Under Axial Compression And Experimental Validation

The buckling process of ship structures under limit load is a very complex mechanics phenomena,which contains strong coupling effect of geometric nonlinearity and material nonlinearity.Experiments with scaled model is one of the efficient ways to estimate the ultimate strength of the real ship with novel structures.Researchers are looking forward to predict the ultimate strength and failure modes of the real ships with the results of the scaled models so as to be enlightened for the improvement of the real ship.However,the current scaled model experiments can hardly meet the needs.The primary reason is that the current similarity criteria which are used to design the scaled models were put forward based on the assumption of linear elastic and small deformation of the structures while the real structures are encountering nonlinear and large deformation before collapse.Therefore,based on this situation,this paper aims to put forward the nonlinear similarity criteria of the buckling process of ship structures,so as to direct the design of scaled models.The main works in this paper are as follows:1)Summarized the previous research progress on the ultimate strength of ship hulls,and demonstrated the importance of model experiments,and got the result that the buckling of stiffened plates under axial compression is the main inducement of the overall buckling of the whole hulls;2)Analyzed the theories and defects of current similarity criteria which is used to design the scaled models;3)Setting stiffened plate under uniaxial compression as the object,derived the nonlinear similarity criteria of the plates and put forward nonlinear similarity design methods.These criteria and method are validated with FEM software and steel models experiments;4)Promoted the nonlinear similarity criteria of stiffened plates under uniaxial compression to box beam under pure bending moment,and put forward the design method of scaled box beam.These methods are validated with FEM software.