Effects of Hybridisation on the Low Velocity Falling Weight Impact and Flexural Properties of Flax-Carbon/Epoxy Hybrid Composites

Abstract

The trend of research and adoption of natural plant-based fibre reinforced composites is increasing, with traditional synthetic fibres such as carbon and glass experiencing restrictions placed on their manufacture and use by legislative bodies due to their environmental impact through the entire product life cycle. Finding suitable alternatives to lightweight and high-performance synthetic composites will be of benefit to the automotive, marine and aerospace industries. This paper investigates the low-velocity impact (LVI) and flexural properties and damage characteristics of flax-carbon/epoxy hybrid composites to be used in structural lightweight applications. LVI, for example, is analogous to several real-life situations, such as damage during manufacture, feasibly due to human error such as the dropping of tools and mishandling of the finished product, debris strikes of aircraft flight, or even the collision of a vessel with another. Carbon fibre has been hybridised with flax fibres to achieve enhanced impact and flexural performance. The failure mechanisms of woven flax and flax-carbon epoxy hybrid composites have been further analysed using Scanning Electron Microscopy (SEM). It was observed from the experimental results that carbon fibre hybridisation has a significant effect on the impact and flexural properties and their damage modes. The results obtained from this study exhibited that the flexural strength and modulus of plain flax/epoxy composite increase significantly from 95.66 MPa to 425.87 MPa and 4.78 GPa to 17.90 GPa, respectively, with carbon fibre hybridisation. This significant improvement in flexural properties would provide designers with important information to make informed decisions during material selection for lightweight structural applications.

Fiber Selection for Reinforced Additive Manufacturing

“…Flax fibers are approximately 70 to 75% cellulose, and range in diameter from 12 to 16 μm, with lengths up to 90 cm [ 15 ]. Flax fibers have undergone testing as hybrid reinforcing materials for composite materials [ 16 ].…”

Fatigue behaviour of flax-basalt/epoxy hybrid composites in comparison with non-hybrid composites

“…In this regard, hybridisation of plies of plant and synthetic fibres represents a significant strategy to reduce weight and carbon footprint of traditional composite materials, while retaining a sufficient mechanical performance to permit structural applications. In particular, it has been shown that hybrid composite materials can improve impact and bending resistance in comparison with non-hybrid ones [4][5][6][7]. According to Dong [8], hybrid composites including plant fibres were fabricated most frequently with glass fibres.…”

Physical, Mechanical and Perforation Resistance of Natural-Synthetic Fiber Interply Laminate Hybrid Composites

“…Figure 4 displays scanning electron microscopy (SEM) pictures of broken surfaces following the impact of plain flax/epoxy composites, which reveal significant fibre breakage and disorder, with one big group of fibres serving as an initial focal point. The following magnification scales (150 and 300) revealed matrix cracking and epoxy debonding from individual fibres, as well as fibre bending and debonding around a kink band in the flax fibre structure, with evident twisted and flattened fibres [ 167 ]. This was similar to the failure modes done by Dhakal et al, as in Figure 5 .…”