Mechanical behavior of carbon/flax hybrid composites for structural applications

Abstract

In this work, the influence of an unidirectional carbon fabric layer on the mechanical performances of bidirectional flax fabric/epoxy composites used for structural applications was studied. Two different bidirectional flax fabrics were used to produce flax fabric reinforced plastic (FFRP) laminates by a vacuum bagging process: one is normally used to make curtains; the other, heavier and more expensive than the previous one, is usually used as reinforcement in composite structures. In order to realize hybrid structures starting from FFRP, an unidirectional UHM carbon fabric was used to replace a bidirectional flax fabric. Tensile and three-point bending tests were performed to evaluate the mechanical properties of the laminates investigated (both FFRP and hybrids). Furthermore, the mechanical behavior of the different bidirectional flax fabrics was analyzed by carrying out tensile tests. The experimental tests showed that the structures reinforced with flax fabrics, normally used to make curtains, present better flexural properties than that of others while, in tensile configuration, these last show higher modulus and strength. Moreover, both FFRP laminates show low mechanical properties, which do not allow their use in structural applications while the presence of one external layer of unidirectional carbon involves remarkable increase in their properties. According to this study, the hybrid composites realized could be used in several structural applications (i.e., nautical and automotive).

Mechanical Characteristics of Two Environmentally Friendly Resins Reinforced with Flax Fibers

“…Nevertheless, the reinforcement has a significant effect on improving the strength of the composites especially in the case of resin 181 EN2X, which behaves better than resin VEef220ST. The results obtained for the first one are consistent with those retrieved in the literature, even if some authors obtained better properties for similar composites [17], [18], [27] and [28]. The data for Table 8 are compared It can be remarked that, thanks to the enhancement provided by the reinforcement, the strength and the stiffness of the environmentally friendly composites made using flax fiber are comparable to those of the reinforced composites made using conventional resins.…”

Upgrading flax nonwovens: Nanocellulose as binder to produce rigid and robust flax fibre preforms

“…In fact, bio-based composites have already found applications in the automotive [2,3], construction and building industries [4,5]. However, natural fibres do suffer from some drawbacks including poor compatibility with hydrophobic polymer matrices and the inherent variability in fibre properties, even for fibres extracted from the same cultivation [1].…”

Hybrid biobased recyclable epoxy composites for mass production

“…The use of NF is however increasing in many sectors . For example, Fiore et al have indicated that flax is the most widely used NF in the European automotive industry, representing 71% of the NF consumed back in 2,000.…”