Buckling of thin-walled cylindrical shells made of mild steel due to vacuum and its prevention-experimental study

Abstract

The aim of this paper is to investigate the buckling due to vacuum and its prevention for various locally manufactured thin-walled closed end cylindrical shells made of mild steel (MS). Length to diameter ratio (L/D) vary from 2.4 to 3.43 and corresponding diameter to thickness ratio (D/t) vary from 390.8 to 558.24 for unstiffened cylinders. While, for cylinders with various types of stiffener setups length to diameter ratio vary from 2.67 to 3.43 and corresponding diameter to thickness ratios vary from 390.8 to 502.42. Using an appropriate setup consisting of a vacuum pump, vacuum was developed within those cylinders, leading to buckling. The pressures at which the cylinders buckled was recorded using the calibrated vacuum gauge. Furthermore, the buckling pressures for cylinders modified with stiffeners were also recorded, and the differences in the buckling pressure between the stiffened and unstiffened cylinders were also investigated to estimate the effectiveness of the stiffeners in the prevention of buckling. In terms of thin-walled MS cylinders manufacturing process in Bangladesh, this paper provides knowledge on the effectiveness of the different types of stiffeners in increasing resistance to buckle.