Asymmetric hybrid composite: A design concept to improve flexural properties of Kevlar Aramid composites

Asymmetric hybridization is proposed as a mechnanism for improvement of flexural properties of composites reinforced with Kevlar^* aramid fiber, where the compressive strength of the fiber is a limiting factor. A calculation based on a bi-material beam model is presented, which determines the placement and arrangement of fibers in a composite such that the stress developed on the tensile side of the composite equals the ultimate tensile strength of Kevlar. An experimental investigation was conducted with asymmetric hybrid composites of J-polymer reinforced with Kevlar and carbon fibers. In the best cases, the observed ultimate flexural and shear strengths were improved by 40% and 25% by comparison with values typically seen for composites of J-polymer and Kevlar.