Influence of localized imperfections on the buckling of cylindrical shells under axial compression

The in~uence of localized imperfections on the buckling of a long cylindrical shell under axial compression is analysed by using a double scale analysis including interaction modes[ This leads to a system of coupled complex non!linear di}erential equations with discontinuous derivatives[ We propose analytical formulas to predict the reduction of the critical buckling load[ 0887 Elsevier Science Ltd[ All rights reserved