Abstract
This research paper focuses on the influence of fibre layering sequence on mechanical and creep properties of kenaf fibre-reinforced unsaturated polyester for structural applications. Kenaf fibre unsaturated polyester composites with 0 °/0 °/0 °, 0 °/+45 °/0 °, 0 °/+45 °/−45 ° and 0 °/90 °/0 ° layering sequence configurations were prepared and analysed. The quasi-static four-point flexural test was performed and the flexural creep properties of each kenaf composite configuration were evaluated as per international standards ASTM D6272 and ASTM D2990 respectively. By using a creep numerical model, namely the Findley model, the creep properties of kenaf fibre composites with four different configurations were modelled. The results show that the highest flexural strength of 44.77 MPa was achieved using the 0 °/+45 °/0 ° configuration, followed by 0 °/90 °/0 ° and 0 °/+45 °/−45 ° configurations. In this study, the performance of the composite with the layering sequence of 0 °/+45 °/−45 ° was the poorest due to its inconsistent layering configurations and composite properties. In terms of flexural creep properties, it can be seen that the 0 °/+45 °/0 ° layering sequence offered significant creep resistance with the most significant elastic modulus of 73% throughout the 720-hour creep test duration. This research shows that the kenaf fibre composites with a layering sequence of 0 °/+45 °/0 ° have the optimum properties, as reflected in ultimate flexural strength values and elastic modulus reduction. It can be established that the kenaf composites with 0 °/+45 °/ 0 ° configuration have the highest potential to be used in structural applications with long-term serviceability such as crossarm in transmission towers.