Mechanical and electrical assessment of hybrid composites containing hollow glass reinforcement

A study has been performed on a series of hybrid composites with hollow gla ss-fibre reinforcement. The materials were tested both mechanically and ele ctrically by means of microwave transmission measurements and waveguide mea surements of fundamental electromagnetic properties. The main effect of add ing hollow glass fibres to the hybrids was to reduce the measured value of dielectric constant, and it was shown that this could be combined with rela tively high values of modulus if a stiff fibre such as Nicalon silicon carb ide was used in the principal load-bearing direction. It was thus demonstra ted that hybrid composites could be produced with a high levels of specific strength, modulus and damage tolerance combined with low dielectric consta nts, offering an attractive route for producing structurally sound electric ally transparent components. (C) 1999 Elsevier Science Ltd. All rights rese rved.