Investigating the Effects of Anisotropy of Knitted Fabric Reinforced Polymer (KFRP) Composite

This paper investigates the mechanical performance of Knitted Fabric Reinforced Polymer (KFRP) composite when subjected to tensile loading. In particular, the effects of the fabric orientation (anisotropy) and temperature are examined. Polypropylene (PP) is used for the matrix, while plain weft knitted Kevlar 29 fiber fabric is used for the reinforcement. Tensile tests are conducted at both room and elevated temperatures. The deformation of the KFRP composite when subjected to tensile loading is observed to be distinctly ductile and predominantly plastic. While the tensile modulus is observed to decrease from the wale direction to a minimum between 45° and 60° with respect to the wale direction before increasing slightly towards the course direction, the ultimate tensile strength is observed to decrease from the wale direction to a minimum at the course direction. There are three different modes of failure which can be defined at the wale, 45° and course directions. Failure at other orientations is found to be a combination of any of these three modes of failure.