Manufacturing and mechanical performance evaluation of resin-infused honeycomb composites

In spite of numerous advantages of open-cell core sandwich composites, the applications have been limited due to the problems involved in manufacturing using low cost processes. Resin accumulation in the core is a major challenge in the fabrication of honeycomb sandwich panels using resin infusion techniques. Foam-filled cores and polymer film barriers are some of the methods used in the literature to address this issue. However, these techniques will increase the weight of the sandwich composites. In this study, honeycomb sandwich panels were manufactured using commercially available film adhesive and modified vacuum-assisted resin transfer molding process. The resin incursion into the core openings was investigated. No accumulation of resin was observed in the core. Flatwise tension, flatwise/edgewise compression, and three-point bending tests were conducted to evaluate the mechanical performance of the sandwich composites. The performance of sandwich panels during a low-velocity impact event was also evaluated. Results indicate that the vacuum-assisted resin transfer molding process can be successfully used to manufacture honeycomb composite sandwich structures using currently available barrier adhesive films.