Local Buckling Design Rules for Profiled Sandwich Panels based on the Studies of Foam–filled Steel Beams

Abstract

Modern composite sandwich constructions have been used very successfully in many aerospace and structural applications. Various aspects of structural behaviour of sandwich panels have been researched for many decades as they are a potential load carrying component in buildings. Sandwich panels exhibit various types of buckling failure modes depending on the types of steel faces used. Local buckling is one of the fundamental failure modes of sandwich panels with profiled faces. To investigate the local buckling behaviour, Davies and Hakmi (1992) conducted a series of bending tests of foam-filled thin-walled steel beams and developed a design method, which is now adopted in the European recommendations for the design of sandwich panels (CIB, 2000). However, recent studies by Pokharel and Mahendran (2003, 2004a, 2004b) have shown that this design method is inadequate for sandwich panels with very slender plate elements, and therefore developed a new design rule that is applicable for a wide range of width to thickness (b/t) ratios of foam supported plate elements. This research was undertaken to investigate the applicability of these design rules based on the results from Davies and Hakmi’s (1992) bending tests of foam-filled steel beams and a numerical study simulating the bending tests. Both the experimental and numerical results were then compared with the predictions from the current and newly developed design rules. This paper presents the details of Davies and Hakmi’s (1992) bending tests and corresponding numerical modelling, evaluation and comparison of results.