Buckling of Axially Compressed Imperfect Steel Cones with Local Dents

This paper presents the comparison of the influence of single and multiple local dents on the load carrying capacity of steel conical shell subjected to axial compression. Cones were assumed to be made from 0.5 mm mild steel with geometric parameters characterized by: r1/t = 50, r2/r1 = 2.0, L/r2 = 2.24, β = 12.6°. Result of fourteen test specimens having local dents ranging from 0 to 2 and indent depth of 0.56, 1.12 and 1.68 is presented in the paper with the accompanying numerical results. The results confirm the strong influence of local dents on the buckling load of axial compressed cones. It is clear that increasing the indent depth results in reduction of the cone strength i.e., the larger the imperfection amplitude, the larger the reduction the buckling load of the cone. Furthermore, it can be seen that cone with multiple dents are more sensitive to imperfection as compared to cone with single dents. Lastly, it can be seen that in most cases, for cone having thinness ratio of 50, two local dents on the mid-surface is enough to produce the largest reduction in the load carrying capacity of the shell as evident for imperfection amplitude A = 0.56 and 1.68. However, as the thinness ratio increase (i.e., r1/t = 250), the greatest reduction in the buckling load of the cone is produced by the highest number of local dents.