Influence of fillers in stiffener core and structural parameters on compaction of t-stiffened skins in autoclave process

Using carbon fibre/bismaleimide unidirectional prepregs, T-stiffened skins were fabricated by integral moulding technology of co-bonding in autoclave. The research was focused on comparing the effects of different filler content and structural parameters (curvature and ply sequence considered) on the compaction of T-stiffened skins. The measurement thickness and observation of micrographs were used to characterise the consolidation and compaction of T-stiffeners, and the experimental results indicated that filler content and structural parameters were both significant factors. A non-uniform thickness distribution and thickening at the corner section of T-stiffeners were observed. For T-stiffeners with quasi-isotropic lay-up, more uniform thickness distribution was obtained under the conditions of rolling unidirectional prepregs as fillers into stiffener core and increasing curvature radius, which could help to compact T-stiffeners and eliminate rich resin defect. The results provided in this study will contribute to understanding of the fracture mechanism of T-stiffened skins.