Ultimate strength and effective width formulations for ship plating subject to combined axial load, edge shear, and lateral pressure

The aim of the present study is to develop closed-form formulations for the ultimate strength of simply supported steel plating subject to a combinati on of longitudinal axial load, edge shear, and lateral pressure. The post-w eld initial imperfections (initial deflections and residual stresses) are i ncluded in the strength formulations as parameters of influence. By solving the equilibrium and compatibility governing differential equations of larg e-deflection plate theory, the membrane stress distribution inside the plat ing under axial and lateral pressure loads is formulated in closed form. Th e ultimate strength formulation for plating under axial load and lateral pr essure is then derived under the assumption that the ultimate limit state i s reached if the plate edges yield. An empirical formula for the plate ulti mate shear strength is suggested based on numerical FE solutions. A relevan t ultimate strength relationship between axial load acid edge shear is then proposed by combining the two sets of the ultimate strength formulations. As another contribution, the effective width formulation for plating under combined axial compression and edge shear which allows for the shear lag ef fect caused by lateral pressure as well as the influence of post-weld initi al imperfections is developed. The validity of the proposed ultimate streng th formulations is shown by comparing with experimental results and nonline ar finite-element analyses. Modeling uncertainty of the developed plate ult imate strength formula against the experimental and numerical results is st udied in terms of bias and coefficients of variation.