Degradation of the compression strength of square plates due to initial deflection

The influence of initial deflections on collapse strength of thin square plates in uniaxial in-plane compression is studied emphasising an integral energy measure of the imperfections. In calculations of the plate strength, measured data on distortions of stiffened plating in ships as well as buckling modes, compound and localised shapes are considered. The strength values are compared normalising the initial deflections by the energy measure or by the commonly employed amplitude to thickness ratio. The paper extends the previous study on strength of rectangular plates [Sadovský Z, Teixeira AP, Guedes Soares C. Degradation of the compression strength of rectangular plates due to initial deflection. Thin-Walled Structures 2005;43:65–82].