The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

Abstract

Mechanical properties of aligned long harakeke fibre reinforced epoxy with different fibre contents were evaluated. Addition of fibre was found to enhance tensile properties of epoxy; tensile strength and Young’s modulus increased with increasing content of harakeke fibre up to 223MPa at a fibre content of 55wt% and 17GPa at a fibre content of 63wt%, respectively. The flexural strength and flexural modulus increased to a maximum of 223MPa and 14GPa, respectively, as the fibre content increased up to 49wt% with no further increase with increased fibre content. The Rule of Mixtures based model for estimating tensile strength of aligned long fibre composites was also developed assuming composite failure occurred as a consequence of the fracture of the lowest failure strain fibres taking account porosity of composites. The model was shown to have good accuracy for predicting the strength of aligned long natural fibre composites.