Comparison of Mechanical Behavior of Biaxial, Unidirectional and Standard Woven Fabric Reinforced Composites

The conventional woven fabrics (plain, twill, satin, etc.) have yarn undulations, that may lead to the fibre breakage and loss of mechanical strength. This problem was resolved using unidirectional woven structures having straight yarns, but they provide strength in one direction only. A possible solution is the use of biaxial fabric having yarns at ±45 ° as reinforcement, but its fabrication cost is too high. The current study focussed on the development of a composite material using conventional fabrics having comparable properties with biaxial fabric composites. Three different reinforcements (plain, twill and unidirectional) were prepared using glass fibre. For composite fabrication, plies were cut, stacked at ±45° and infused with unsaturated polyester resin to produce a composite equivalent to the biaxial composite. Similarly, the stitched composites were also fabricated by stitching the similar stack (using chain stitch class 101) before impregnating with resin. Laminated composites from biaxial fabric (both stitched and unstitched) were also produced for comparison. All these composites were characterised for tensile and impact properties. The tensile strength of stitched unidirectional composites was higher as compared to the other woven and biaxial structures. Similarly, the impact strength was also higher for stitched unidirectional composite. Hence, the ±45° stacked unidirectional composite may be used as a potential replacement of biaxial composite.