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Abstract

In composite structures, drilling of holes leads to local fracture of the area around the cutting plane. Therefore, to prevent composite structures from weakening due to cracks induced by cutting, knitted fabrics with knitted-in holes were manufactured. The advantage of this fabric is that the area around the hole is strengthened by an increased fiber volume fraction and an orientation of the fibers circumferential to the hole. The tensile properties of single layer knitted aramid fiber/epoxy composites with knitted hole were compared with drilled hole. For all specimens with a drilled hole, the region around the hole caused final failure. For composites with a knitted hole, however, in the case of specimens with the ratio of specimen width to hole diameter, WID > 3, the region around the hole mostly did not lead to final failure. Therefore, open hole strength with knitted hole was higher than that with drilled hole.

Keywords

aramid fiber knitted composites knitted hole open hole tensile test WID ratio progressive failure

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Open Hole Tensile Behaviors of Knitted Fabric Composites

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