Kh. Leong et al., The effects of deforming knitted glass fabrics on the basic composite mechanical properties, J MATER SCI, 34(10), 1999, pp. 2377-2387
The effects of deforming knitted fabrics on the tensile and compressive pro
perties of their composites have been investigated for the weft-knit Milano
rib fibre architecture. The properties have been studied for both the cour
se and wale directions for composites with fabrics deformed in either of th
e two directions. It was found that any change in the mechanical properties
of the deformed composites with respect to their undeformed counterpart is
strongly related to the changes in the knit structure brought about by the
induced deformation to the knitted fabric. Deformation in the knitted fabr
ic also affects the tensile fracture mode whereby increased deformation, be
it wale- or course-wise, transforms transverse fracture to shear fracture
in either loading axis. On the contrary, the compressive fracture mode is i
nsensitive to fabric deformation. Fractographic studies using stereo-optica
l and scanning electron microscopy have further revealed that tensile failu
re is caused by fibre breakages occurring at two locations of the knitted l
oops-one, at the leg components and, two, at fibre crossover points, whilst
compression failure is controlled by Euler buckling of the looped fibres o
f the knitted composite. All these characteristics were revealed to be rela
ted to the microstructure of the knitted composite laminates. (C) 1999 Kluw
er Academic Publishers.