Investigation of the possible origins of the differences in mechanical properties of hemp and flax fibres: A numerical study based on sensitivity analysis

Abstract

Despite the great similarities in the physical and chemical properties of flax and primary hemp fibres, literature generally reports differences in their average tensile properties. This work proposes a numerical investigation of the relationships between the morphological, biochemical and cell wall features, along with their variability, and the mechanical properties of flax and hemp fibres. A previously developed 3D micromechanical model of plant fibre is used to carry out a sensitivity analysis.Results show that the difference observed in the average tensile properties of flax and hemp fibres is partly due to the differences in scattering of some their morphological and ultrastructural properties. Despite a similar mean value, the reduced variability in the flax fibre features, seems to lead to higher average tensile properties.

Influence of force volume indentation parameters and processing method in wood cell walls nanomechanical studies

“…Using Eqs. (1) and (2), the area function can be expressed as a function of the indentation depth as:…”

“…However, what prevents a generalization of the use of these materials is, among others, the wide variability of their mechanical properties. Variability at the scale of the work-piece is heavily influenced by the variability at the fiber scale 2 . Indeed, wood is a multi-scale material whose mechanical support function is ensured by the fiber’s walls.…”

Elaboration by Wrapping Process and Multiscale Characterisation of Thermoplastic Bio-Composite Based on Hemp/PA11 Constituents

“…Flax fibres generally have slightly better tensile properties than hemp fibres, especially in terms of tensile strength and stiffness; on the other hand, they reach a lower tensile strain at failure than hemp [5]. If a lot of studies are conducted at the scale of fibres to explain these differences [1, [5][6][7], few papers are dedicated to the development of hemp-continuous fabrics used as reinforcement of composite samples [4,8,9]. This deficit for hemp could be attributed to technological barriers, such as fibre separation and the alignment of fibres throughout the transformation process and consequently the unavailability of these products on an industrial scale [10].…”

“…Despite numerous similarities (cell wall, thicknesses, and numbers of layers/sub-layers, biochemical composition, cellulose microfibril angle, MFA), these two bast fibres generally exhibit differences in their tensile properties and their global tensile behaviour. Flax fibres generally have slightly better tensile properties than hemp fibres, especially in terms of tensile strength and stiffness; on the other hand, they reach a lower tensile strain at failure than hemp [5]. If a lot of studies are conducted at the scale of fibres to explain these differences [1, [5][6][7], few papers are dedicated to the development of hemp-continuous fabrics used as reinforcement of composite samples [4,8,9].…”

Towards hemp fabrics for high-performance composites: Influence of weave pattern and features

“…The increase in environmental awareness has stimulated the idea of reducing synthetic-based products in the production of composite materials and more specifically of reinforcements [1]. To achieve this objective of reducing the use of synthetic fibers, the incorporation of cellulosic fibers such as flax, hemp or kenaf has received the attention [2][3][4]. Indeed, their specific mechanical properties are competitive when compared to glass fibers and they have greater environmental benefits [5][6][7][8].…”