Effects of Fibre-Volume Fraction on the Mechanical Properties of Ukam Fibre-Reinforced Polyester Resin Composites

Abstract

This research is aimed at studying the composite of Ukam plant fibre-reinforced polyester resin with a view to determining the effects of fibre-volume fraction on its mechanical and physical properties. From the experimental work and the tests carried out, It was observed that increase in fibre volume fraction (Vf ) reduces the hardness and the compressive strength; increases the tensile strength and the longitudinal modulus of the composites. At 10% and 30% Vf, hardness was observed to be 509.2MPa and 412.49MPa; compressive strength was 165.67MPa and 96.5MPa; Tensile strength was 34.72MPa and 83.33MPa; Longitudinal modulus was 12.6 MPa and 35.8 MPa respectively. It was observed that Ukam plant fibres are very effective in increasing the composite modulus in the longitudinal direction: As the fibre-volume fraction increases, the ratio Ec/Em also increases. The transverse modulus of a unidirectional composite is much smaller than its longitudinal modulus. As a result, the ukam plant fibres are much less effective in raising the composite modulus in the transverse direction than in the longitudinal direction. It was also observed that the mechanical properties of the composite of ukam fibrereinforced polyester resin were optimum at 30% Vf. Its properties were therefore determined at 30% Vf.: Tensile modulus 2.78GPa; Compressive modulus 165.67MPa; Tensile strength 83.33MPa; Hardness 138.78MPa; Shear strength 27.25MPa; Ultimate strength 30.25MPa; Bending strength 68.85MPa respectively.