Failure of cross-ply NCF composites under off-axis compressive loads - An experimental study and a new strength prediction model including fibre bundle waviness

Abstract

Abstract The design of reliable and efficient mechanical joints with non-crimp fabric (NCF) composites depends on several factors but knowledge on actual loading direction and an accurate compressive strength prediction is essential. Motivated by this, the current study is focused on the compressive strength of cross-ply NCF composites and the influence of fibre orientation in relation to the loading direction. Possible influence of stacking sequence on the compressive strength is also studied. Compression tests of cross-ply NCF composite laminates that are loaded at various off-axis angles are performed and the failure mechanisms are identified. An analytical semi-laminar based model for strength prediction of NCF composite laminates loaded in compression is then suggested. The model take in- and out-of-plane bundle waviness into account. Good agreement between the proposed model and experiments is observed.