Since the composite material has high specific rigidity and specific strength as well as excellent mechanical and chemical properties compared to the existing metal material, the composite material has attracted attention as a replacement material for...
Since the composite material has high specific rigidity and specific strength as well as excellent mechanical and chemical properties compared to the existing metal material, the composite material has attracted attention as a replacement material for a structure requiring high efficiency. Layered composite materials generally applied to aircraft structures have excellent in-plane physical properties where fibers are arranged, but they are not arranged in the direction where fibers are stacked, that is, in a thickness direction, so they are vulnerable to thickness loads. The I-fiber stitching method, a method that complements the Z-pinning and existing stitching methods, is used to reinforce these shortcomings. The I-fiber method is a method of maximizing the reinforcing effect by arranging discontinuous reinforcing fibers in the thickness direction of the composite material and forming a bolt head-like shape using residual fibers. By discontinuously cutting and inserting fibers, the limitations of the use of reinforcing fibers can be overcome, and it can be applied to various structures compared to the existing stitching method. In this research, a unit cell specimen was manufactured using the I-fiber stitching method, a three-dimensional composite reinforcement method, and the reinforcement effect of a single fiber was evaluated according to the shear strength and reinforcing fiber angle through test and analysis.