The effect of shear span-to-depth ratio and test set-up on the behavior of fibre composite sandwich structure

The shear strength of the core material is a critical parameter and is an important consideration when designing a composite sandwich structure in construction application. In this paper, the shear behaviour of a new generation composite sandwich panel made up of glass fibre composite skins and phenolic core was investigated under three-point loading short beam (SB) and asymmetrical beam shear (ABS) tests. The effect of the shear span-todepth ratio (a/D) was examined on the shear strength and failure behaviour of the fibre composite sandwich beams. The results showed that the shear behaviour of the beams is affected strongly by the a/D ratios. The beams with a lower a/D ratio failed at a higher load compare to the beams with larger a/D ratio. In general, the sandwich beams tested under ABS failed at a significantly higher load than that of the sandwich beams tested under SB for the same a/D ratio. The results also showed that the behaviour of the fibre composite sandwich beams is governed by the strength of the phenolic core material. In all the tested sandwich beams, the failure of the core occurred under the loading point where the shear force and bending moment are maximum.