Fabricación y evaluación de paneles sándwich ultra-livianos de fibra de carbono

JUAN PABLO VITALE; GASTON FRANCUCCI; HELMUT RAPP; ARIEL STOCCHI

Cordoba

Simposio; SAM-CONAMET 2016 Simposio materiales y tecnologías para la industria metalmecánica y aeroespacial.; 2016

Sandwich structures are widely used in applications were low weight and high bending strength and stiffness are required, such as the transportation and aerospace industry. Sandwich panels consist of a thick layer (core) intercalated between thin-stiff layers (skins). The development of high performance cores, such as 3-dimensional carbon fiber reinforced polymer (CFRP) cores allows optimizing the strength (and stiffness) to weight ratio of the panels. This core configuration combines the advantages of 2-dimensional honeycombs and hollow cores. In this work, carbon fiber cores were obtained using an interlocking method. Flat composite plates were manufactured by the vacuum infusion (VI) technique using bidirectional woven carbon fiber fabrics and epoxy resin. These laminates were cut by water-jet into three different geometrical patterns that were interlocked and bonded together following a square pattern. In this way, ultra-light weight cores were obtained with densities lower than 48kg/m3.The mechanical performance (compressive and shear strength) and the failure modes of the three different cores were evaluated. Results were compared to those predicted by an analytical model and FEM (Finite Element Method) analysis. The expected performance of the cores was substantially higher than the obtained during the mechanical tests. This was attributed to manufacturing imperfections (mainly voids) in the composites comprising the core walls that were neglected in the models.