Tensile Characteristics of Through-the-thickness Stitched E-Glass/Epoxy Composite

In this paper, the effects of through-the-thickness stitches on the tensile properties of E-glass/epoxy composite laminates; namely the tensile modulus, tensile strength and Poisson s ratio, have been investigated experimentally. In the adopted stitching scheme, a high-tenacity polyester stitch yarn is used along warp yarns of an eight-layer plain woven fabric. Vacuum infusion process (VIP) method is used to manufacture the composites, which resulted fiber volume fraction of specimens above 60%. The specimens are fabricated and the tensile tests are conducted according to ASTM D3039 in order to generate the stress-strain curves. The experimental results have indicated that the tensile properties of stitched laminates have diminished in comparison to those related to the non-stitched ones. Although the aforementioned reduction in tensile properties has occurred in both warp and weft (longitudinal and transverse) yarns directions, it is less pronounced along the stitch line (i.e. in the warp direction).

Keywords:

Tensile properties , Plain woven composites , Stitch , VIP method.