Vertically-aligned short E-glass fibre core sandwich composite: Production and evaluation

• Published in: The journal of sandwich structures & materials 2022-01, Vol.24 (1), p.174-200
• Main Authors: White, Robbie, Machavaram, Venkata R, Fernando, Benjamin A, Paget, Mark A, Prasad, Ashwini, Fernando, Gerard F
• Format: Article
• Language: English
• ISSN: 1099-6362; 1530-7972
• DOI: 10.1177/1099636221993883

This paper reports on the production and evaluation of a new class of “Z-axis” composite sandwich panel where the core consists of a dense array of vertically-aligned, 3 mm long E-glass fibre composite “beams”. The E-glass fibre bundles were aligned using electrostatic charging. A procedure was developed to retain the orientation of the short-fibre bundles whilst they were impregnated and cured with an epoxy/amine resin system. The skins were manufactured from 4-ply carbon/epoxy prepregs with a layup sequence of (0,90)s. The out-of-plane compressive strength of these Z-axis composites was found to be 25.2 and 15.2 times greater than equivalent sandwich panels made with Nomex® and aluminium honeycomb cores respectively. Their compressive strength was found to increase in proportion to the density of the core. Buckling and fracture of the vertically-aligned Z-axis composite were the predominant failure modes observed. The shear and flexural properties of the Z-axis composites were comparable to equivalent honeycomb sandwich panels manufactured from Nomex® and aluminium honeycomb cores.