Author(s)

N.S. Marshall & G.N. Nurick

Abstract

An experimental investigation showing the effect of induced imperfections on the symmetric progressive buckling of thin-walled square mild steel tubes is presented. The imperfections include: a circular hole; indentations of various shapes; and combinations of a hole positioned centrally in an indentation. In all cases identical imperfections were induced symmetrically in opposite walls of the tube. The results indicate that the ultimate buckling load of the tube decreases with an increase in the severity of the imperfection. The distance between the plastic hinges that form the first lobe of buckling decreases with two opposing holes, but increases with large indentations. The change in the size of the first lobe leads to ins

Keywords