Investigation On Nonlinear Finite Element Analysis Method For The Ultimate Strength Of Platre Frame Anf Hull Girders

Structure ultimate strength is the most important part of Common Structural Rules(CSR).Nowadays,nonlinear finite element analysis method for the ultimate strength of hull girders was allowed in the new CSR-H rules.But there was no explicit provision on model size,mesh,imperfection and boundary conditions.So it is full of theoretical significance and practical value to study the nonlinear finite element analysis method for the ship's structure ultimate strength and the factors.In this paper nonlinear finite element calculation on ultimate strength of stiffened panels have been taken with the three bay /one span model.The result of benchmark study among the one bay/one span model,two bay/two span model and three bay /one span model have been carried out.On this basis,another study on the factors of buckling span plate rack including the model range,beam height and lateral loads have been finished.Ultimate strength analysis of the DOW's 1/3-scale welded steel frigate model has been taken in this paper.Model size,cell type,mesh density,boundary conditions,initial imperfections,residual stresses and analytical methods are all been considered.Some models of real ship was established to analysis the ultimate strength,such as the one bay,one cabin and three cabin model of tankers,bulk carriers and bulk carriers with large openings.At last this paper discussed the impact on the ultimate strength of the model range comparing to the result of Smith method.