Elastic local buckling strength of stiffened plate considering plate/stiffener interaction and welding residual stress

Abstract

An analytical formula for estimating elastic local buckling strength of a continuous stiffened plate subjected to biaxial thrust is derived considering the influence of plate/stiffener interaction and welding residual stresses. Through a comparison of calculated results with those by FEM eigenvalue analysis, high accuracy of the proposed formula is demonstrated. A series of buckling strength analyses is performed on the deck and bottom plating of actual ships. It has been found that: (1) In the case of stiffened plates in ordinary ships, an increase in the elastic local buckling strength as a result of stiffener torsional rigidity is almost compensated for by the influence of welding residual stresses. (2) For a thin plate under transverse thrust, higher elastic buckling strength can be expected than that specified in the classification societies’ rules by selecting an appropriate size for the stiffener.