Study of integral hat-stiffened composite structures manufactured by automated fiber placement and co-curing process

Abstract

Integrated and automated manufacturing processes of advanced composites have attracted extensive attention, aiming at the improvement of mechanical performance and cost efficiency of composites. This experimental study investigated the feasibility of a manufacturing process for co-cured integral hat-stiffened panels based on automated fiber placement. To achieve desirable manufacturing quality and simplify manufacturing process, a novel flexible inner mold was designed for the enclosed cavity between stringers and skin, which was suitable for curved and large hat-stiffened panels. Influences of flexible mold and processing parameters on dimensional accuracy were studied by both finite element analysis and experimental methods. Moreover, fiber distribution around the transition region between skin and stringer were obtained through microscopy observation. With the optimum inner mold and layup processing parameters, hat-stiffened composites can be manufactured integrally with improved surface quality and geometric accuracy, based on co-curing process and automated fiber placement.