Influence of dislocations and plasticity on the tensile behaviour of flax and hemp fibres

This paper presents finite element analyses of the tensile behaviour of elementary fibres of flax and hemp, focusing on the non-linear tensile behaviour of the fibres and the relationship between the stiffness and the diameter of the fibre. The non-linear tensile behaviour is modelled by introducing dislocations in the helical structure of the cellulose fibrils and assuming that the hemicellulose has an elastoplastic constitutive relation. The relationship between the elastic stiffness and the diameter of the fibres is analysed similarly, using an elastic constitutive behaviour of the hemicellulose. The results agree with experimental results found in the literature.