Non-linear buckling response of unstiffened laminated composite cylinders using different geometric imperfections

Abstract

The important role of geometric imperfections on the decrease of the buckling load for thin-walled cylinders had been recognized already by the first authors investigating the theoretical approaches on this topic. However, there are currently no closed-form solutions to take imperfections into account already during the early design phases. Since 1970s a considerable number of experimental and numerical investigations have been conducted to develop new stochastic and deterministic methods for calculating less conservative KDFs. Among the deterministic approaches many suggest the use of different geometric imperfection patterns in order to investigate the imperfection sensitivity but there is no consensus about which imperfection pattern is the correct one. The present study will investigate the effect of five different imperfection patterns on the non-linear buckling response of unstiffened laminated cylinders with the aim to bring about general directives that can be used as future reference.