Hawraa Ali Nasir, Mustafa Baqir Hunain
Composite materials are widely used in engineering applications due to their high strength-to-weight ratio and tunable mechanical properties. This research aims to investigate the effect of equi-biaxial pre-tensioning load on the mechanical performance of epoxy composites reinforced with glass fibers at weight fraction of 0.35%. Four pretension load levels (0, 400, 800, and 1200 N) were applied to the fibers prior to fabrication. Tensile, impact, and flexural tests were performed to evaluate the composite behavior. The results showed that preloading significantly improved the mechanical properties, with optimal performance achieved at 800 N. At this level, tensile strength, elastic modulus, and impact strength increased by 50.14, 27, and 49.75%, respectively. and flexural properties also improved, while the flexural stress and modulus increasing by 263.3% and 76%, respectively. In contrast, increasing the pretension load to 1200 N resulted in a reduction in properties. These findings indicate that applying an optimal equi-biaxial pre-tension load during fabrication effectively enhances the overall mechanical performance of glass fiber-reinforced epoxy composites