Effect of stitch and biaxial yarn types on tensile, bending, and impact properties of biaxial weft-knitted composites

Abstract

Within the scope of experiments, the effect of stitch yarn type (aramid, glass and nylon), and biaxial, warp and weft, and yarn type (aramid and glass) was investigated in the biaxial weft-knitted (BWK) composites. Five different types of composite panel, which include fiber contents, such as glass-glass-glass, glass-glass nylon, glass glass aramid, aramid glass aramid and aramid aramid aramid were fabricated by hand lay-up method. After production of composite panels, tensile, three-point bending and three-point, bending impact tests were conducted on specimens. Microstructural characterization of tested materials was performed using a scanning electron microscope. This study showed that composites with BWK preforms consisting of fiber combinations, such as aramid-aramid-aramid, had higher tensile strength (in course direction), of aramid-glass-aramid had higher bending strength (in course direction), and of glass glass aramid had higher three-point bending impact properties (in course and wale directions) than other types of tested composite structures.