Effect of potting support design on compression buckling of composite cylindrical shells

Abstract

The design of thin-walled cylindrical shells under compression loading is mostly driven by buckling considerations. However, accurate experimental evaluation of the buckling load is challenging due to small variations in boundary conditions due to manufacturing tolerances in support conditions. To test a cylindrical shell under compression loading, potting support is usually created around its bottom circumference to avoid edge crippling that could otherwise drastically reduce its critical buckling load. Therefore, investigating the effects of the potting support on the buckling response of cylindrical shell structures is important to mimic boundary conditions as close as possible to real structural constraints of the boundary. The main objective of this work is to investigate the effects of single and double-sided potting supports on the critical linear buckling load of composite cylindrical shells under compression loading. Then, this paper provides insights into understanding underlying reasons for the deviations of theoretical buckling loads from their corresponding experimental values due to boundary conditions, which can occur independently from, or in combination with, geometric imperfection sensitivity. Finally, robust linear buckling expressions that can help designers estimate the reduction due to support conditions are presented. These expressions can be used for evaluating initial safety margins for the potting support design used for testing cylindrical shells.