Abstract
In this work, the manufacturing characteristics and a performance evaluation of carbon fiber–reinforced epoxy honeycombs are reported. The vacuum-assisted resin transfer molding process, using a central injection point, is used to infuse a unidirectional dry slit tape with the epoxy resin system Prime 20 LV in a wax mold. The compression behavior of the manufactured honeycomb structure was evaluated by subjecting samples to quasi-static compression loading. Failure criteria for the reinforced honeycombs were developed and failure maps were constructed. These maps can be used to evaluate the reliability of the core for a prescribed loading condition. Improvements in the load-carrying capacity for the reinforced samples, as compared with unreinforced specimens, are discussed and the theoretical predictions are compared with the experimental data. The compression test results highlight a load-carrying capacity up to 26 kN (~143 MPa) for a single hexagonal cell (unit cell) and 160 kN (~170 MPa) for cores consisting of 2.5 × 3.5 cells. The failure map indicates buckling to be the predominant mode of failure at low relative densities, shifting to cell wall fracture at relative densities closer to a value of 10−1. The resulting energy absorption diagram shows a monotonic increase in energy absorption with the increasing t/l ratio of the honeycomb core cell walls.
Highlights
Honeycomb cores are predominantly used in sandwich panels finding applications in a variety of lightweight structures in the aerospace sector
A honeycomb core template was manufactured from acrylonitrile butadiene styrene (ABS) polymer using a 3D printer, Connex 260, with a build volume of 260 × 260 × 200 mm
TThXe1m10e0chanical pe2r.f3or×m1a0n11ce of composite ho5n.0ey×c1o0m10bs was determine0d.3by subjecting them to out-of-plane compression loading
Summary
Honeycomb cores are predominantly used in sandwich panels finding applications in a variety of lightweight structures in the aerospace sector. Common aircraft structures in which honeycombs are used include fairings, spoilers, helicopter blades, galleys, flooring, wall panels, and so forth [1]. Many of these structures use aluminum and/or aramid paper–based honeycombs, due to their high strength-to-weight ratio and excellent fire, smoke, and toxicity performance. Aramid-based cores such as NomexTM offer advantages that include a lower cost and density compared to aluminum cores Both cores are sensitive to moisture and exhibit structural deficiencies under prolonged moisture exposure. To overcome these drawbacks whilst improving strength and stiffness, the search for structurally-efficient materials has led to the development of fiber-reinforced composite honeycombs. Vivolo et al [6] investigated the noise, vibration, and harshness (NVH) behavior of fiber-reinforced thermoplastic cores and reported improvements in transmission loss values after reinforcement
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.