Influence of core fillers on resin flow and fiber compaction of cocured skin-to-stiffener structures

The integral molding technology is the development of composite structures. In this study, an experimental integral technology of cocuring was applied to fabricate T-stiffened skins. A study was undertaken to determine the effect of fillers in stiffener core on resin flow and fiber compaction of T-stiffened skins. A new application of transferring pressure film was carried out to measure the pressure distribution in T-stiffeners. The characteristics of resin flow were investigated by the bleeding quantity and the stiffener thickness in prebleeding process. The experimental results indicated that nonuniform pressure obviously distributed in T-stiffeners, especially the lowest pressure exhibited in stiffener corner. Resin-rich defect and highest thickness were frequently obtained in stiffener corner. However, rolling unidirectional prepregs as fillers into the stiffener core of T-stiffened skins caused an increase of pressure in stiffener corner, gave the stiffener corner to the opportunity to remove the resin-rich defect by hindering resin flow into the stiffener corner, and consequently contributed to a significant increase in the fiber compaction and manufacturing quality of T-stiffeners.