Buckling and ultimate strength interaction in plates and stiffened panels under combined inplane biaxial and shearing forces

Abstract

The main portion of a ship's structure is usually composed of stiffened plates. Between girders and floors, stiffeners are furnished to plates usually in the longitudinal direction. Under various loads applied to a ship, such as those due to cargo, buoyancy and waves, these stiffened plates are subjected to combined inplane and lateral loads. Imperfections due to fabrication exist mainly in the form of initial deflection and residual stresses. The behaviour of perfectly flat plates is, however, an important reference in design. In this paper, buckling, ultimate and fully plastic strength interaction relationships for rectangular perfectly flat plates and uniaxially stiffened plates subjected to inplane biaxial and shearing forces are derived and expressed in explicit forms based on the results of theoretical investigations of the non-linear behaviour of plates and stiffened plates. The accuracy of these interaction relationships is confirmed through comparison with the results of other analysis methods. With the aid of these interaction relationships, buckling load, ultimate strength andlor fully plastic strength of such perfectly fat plates and uniaxially stiffened plates subjected to inplane loads may be predicted by hand calculation.