Analysis On Buckling And Ultimate Strength Of Ship Plating

The ship's hull is a thin-walled box girder structure composed of stiffened panels.The overall failure of a ship hull girder is normally governed by buckling and plastic collapse of the deck,bottom,or sometimes the side shell stiffened panels.Therefore,the analysis of buckling and ultimate strength of ship panels in deck,boltom,and side shells is very important and necessary for the safety assessment of ship structure.In stiffened panels,local buckling and collapse of plating between stiffeners is a basic failure mode,and thus it would also very important to evaluate the buckling and ultimate strength interaction of plate elements under combined loads.The buckling and ultimate strength of ship plating normally depend on a variety of influential factors, namely geometric / material properties, loading characteristics, initial imperfections(i.e. initial deflections and residual stresses), boundary conditions and corrosion, fatigue cracking.The plating in ships is generally subjected to combined in-plane and lateral pressure loads.In-plane loads include biaxial compression/tension and in-plane bending and edge shear,which are mainly induced by overall hull girder bending and/or torsion of the vessel.Lateral pressure loads are due to water pressure and cargo.The aims of this thesis are buckling and ultimate strength.Its Main content is as follows: Emphasizes the significance and purpose of the research in buckling and ultimate strength,and reviewing the status in this field,and puts forward the research task; Analyzes and discusses the design formulations for the buckling strength of the ship plating,in which the influence of residual stresses, lateral pressure,cut-outs and rotational restrains is taken into account. According to the nonlinear governing equations of the large deflection plate theory,the ultimate strength formulations of the plate elementsunder combined loads are developed by taking into account the effects of initial imperfections. According to the FEA model of 110, 000DWT oil tank,the distribution of the stresses of the model in more than ten kinds of load cases is calculated.The structural strength of the ship is assessed.The buckling assessment of the main ship plating such as the deck,bottom,side shell,inner shell, longitudinal and transversal bulkhead is undertaken.