In an effort to study impact damage mechanism of Kevlar multiaxial warp knitted fabric composites, the impact behavior and damage tolerance were characterized based on energy approach and compared with those of Kevlar woven laminates. The total impact energy was classified into four terms of delamination energy, membrane energy, bending energy and rebounding energy. Membrane and bending energy were calculated by the image analysis of deformed shape of the impacted specimen while delamination energy was decided using deplying technique. Multiaxial warp knitted composites(MWKs) showed higher impact fracture toughness and bending properties, which resulted in delamination energy and bending energy increase, while membrane and delamination energy were dominant factors for woven laminates. Delaminated area of woven laminates was much larger than those of MWKs, while delamination energy absorption was slightly higher since the impact fracture toughness of woven laminate was much smaller than those of MWKs.

In an effort to study impact damage mechanism of Kevlar multiaxial warp knitted fabric composites, the impact behavior and damage tolerance were characterized based on energy approach and compared with those of Kevlar woven laminates. The total impact energy was classified into four terms of delamination energy, membrane energy, bending energy and rebounding energy. Membrane and bending energy were calculated by the image analysis of deformed shape of the impacted specimen while delamination energy was decided using deplying technique. Multiaxial warp knitted composites(MWKs) showed higher impact fracture toughness and bending properties, which resulted in delamination energy and bending energy increase, while membrane and delamination energy were dominant factors for woven laminates. Delaminated area of woven laminates was much larger than those of MWKs, while delamination energy absorption was slightly higher since the impact fracture toughness of woven laminate was much smaller than those of MWKs.

Keywords: