The hybridisation effect on the viscoelastic properties of polymeric composites

Abstract

Tensile and flexural properties of hybrid composites are reasonably well understood, but the same is not true for other loading modes, such as the viscoelastic behaviour. Therefore, this work intends to study the fibre hybridization effect on the viscoelastic properties of fibre-hybrid composites. For this purpose, experimental tests were carried out in bending mode involving glass and carbon fibres and the results compared to those obtained with full glass fibre and full carbon laminates. The presence of glass fibres decreases the bending properties and this decrease increases with the glass fibre content. Independently of the material, higher strain rates promote higher maximum bending stresses and bending modulus. In terms of stress relaxation, and compared to full carbon fibres, the stress value after 180 min is 1.2% and 2.6% lower for 6C+2G and 4C+4G laminates, respectively, evidencing the most sensitive behaviour of the glass fibres to the stress relaxation. Regarding the creep behaviour, the displacement increases with the time, and the creep displacement after 180 min is greater with the highest content of glass fibers. Compared to full carbon fibers, the displacement value is 0.6% and 2.7% higher for 6C+2G and 4C+4G laminates, respectively.