Laberge Lebel, L. and Trudeau, P., "Preforming of a Fuselage C-Shaped Frame Manufactured by Resin Transfer Molding," SAE Int. J. Aerosp. 6(2):508-512, 2013, doi:10.4271/2013-01-2214.
The need for efficient manufacturing approaches has emerged with the increasing usage of composites for structural components in commercial aviation. Resin Transfer Molding (RTM), a process where a fiber preform is injected with resin into a closed tool, can achieve high fiber content required for structural components as well as improved dimensional accuracy since all surfaces are controlled by a tool surface.Moreover, RTM is well suited for parts that can be standardized throughout the aircraft, such as a fuselage frames and stringers. The objective of this investigation is to develop a preforming approach for a C-Shaped Fuselage frame. Two approaches are proposed: tri-axial braiding and hand lay-up of Non-Crimp Fabrics. The fiber architecture of the basic materials as well as the complete preforms is explained. The necessary preforming operations are detailed. The quality control measurement of fiber orientation and thickness are presented. A relation between the fabric lay-up angle, the fabric construction and the potential defects is drawn. The fiber architecture of the molded part is reported. The fiber volume content and void content of C-Shaped frames are measured using the acid digestion method. The outcome of this study can be applied to the fabrication of aircraft frames.