Role of nano-silica in tensile fatigue, fracture toughness and low-velocity impact behaviour of acid-treated pineapple fibre/stainless steel wire mesh-reinforced epoxy hybrid composite

Nano-silica toughened epoxy hybrid composites were prepared along with pineapple fibre and stainless steel wire-mesh and characterized for its tensile fatigue, fracture toughness and low-velocity impact behaviour. The principal aim of this research work is to reveal the effect of adding high modulus stainless steel and high toughness nano-silica along with pineapple fibre in fracture characteristics of epoxy hybrid composite. Both the pineapple fibre and wire-mesh were surface treated by using H₂SO₄ for better adhesion of reinforcements with the matrix medium. Epoxy hybrid composites were prepared using hand layup method followed by room temperature curing for 48 h. The tensile fatigue results revealed that the composite, which contains nano-silica of 1.0 vol% along with epoxy, pineapple fibre and wire-mesh in PF/SS/PF/SS arrangement gives the highest life cycle of 28520 counts. Similarly the composite, which contains nano-silica of 1 wt% along with epoxy, pineapple fibre and wire-mesh in PF/SS/PF/SS fibre pattern (EFW₂₂) gives the highest energy release rate of 0.86 MJ m⁻². The low-velocity drop load impact results show that the composite, which contains epoxy, fibre and wire-mesh in PF/SS/PF/SS (EFW₃₂) fibre arrangement with 1.0 vol% of nano-silica in epoxy resin gives very high penetration resistance and energy absorption compared to other composite designations. From strength factor calculations the composite made with epoxy, fibre, wire-mesh with PF/SS/PF/SS stacking sequence along with 1.0vol% of nano-silica (EFW₂₂) scores higher normalized strength of 98%. This high fatigue, fracture toughness and high penetration resistance against drop load epoxy composites could be an alternative material for automobiles, structural, surveillance mini air-crafts and domestic appliances manufacturing industries with high economic conditions. (paper)