Buckling of composite domes with localised imperfections and subjected to external pressure

It is shown that Force-Induced-Dimple (FID), initial geometric imperfection leads to a far worse deterioration of buckling strength (for up to four times) than currently used modulated eigenshape(s) or lower bound increased-radius shape deviations from perfect geometry. The FID approach provides not only safer estimates of buckling resistance but also it is efficient in terms of computing time for a range of shell geometries. The physics behind the FID-concept is closer to reality than in the other two approaches.