Co-cured manufacturing of advanced composite materials using vacuum assisted resin transfer molding

Akın, Mert
Sub-structures of aircraft structures mainly consist of stiffened shells such as fuselage frames, ribs, and multi-cell box beams. Conventionally, these stiffened shells are manufactured through a process wherein shells and stiffeners are fabricated separately and then are integrated either through mechanical fastening or adhesive bonding. Co-curing is an integral molding technique that can greatly reduce the part count and the final assembly costs for composite materials. In this study, a low-cost co-curing manufacturing technique for stiffened shells of aircraft structures, particularly multi-cell box beams, is developed. Foam material, foam strength, curing operation and foam coating are considered to be the process parameters and the process is improved by optimizing these parameters. The study also has a wider goal of aiding the simulation tools of composite material processing by providing a material data, including preform permeability, porosity, and resin viscosity model. For this purpose, the three-fold approach is followed. First, an extensive characterization of the preform and the resin properties is performed. Then, resin impregnation simulations of the co-cured three-cell box beam are performed. In the final part, the co-curing manufacturing technique is developed and the co-curing process is compared with the conventional method, secondary bonding, from part bending strength, manufacturing and energy consumption perspectives. The four-point bending test results show that the co-cured part withstands 95% higher load and fails at 99% higher load compared to the secondary-bonded part. Additionally, it is found that almost 57% energy and 25% labor time savings can be achieved by using the co-curing technique.
Citation Formats
M. Akın, “Co-cured manufacturing of advanced composite materials using vacuum assisted resin transfer molding,” M.S. - Master of Science, Middle East Technical University, 2018.