A geometrical model for a two-layer woven composite reinforcement fabric

An investigation is reported concerning the structure of woven fabrics used for composites, and in particular the manner in which layers of fabric are stitched together by interchanging specific yarns between different layers during the weaving process. Two-layer glass-fibre fabrics were woven and tested. In addition to interlaminar shear strength, measurements of tensile strength were recorded and the results related to the fabric structures as observed from photomicrographs. A method was used to determine the angles at which the yarns lie to the plane of the fabric, and the relationship between these angles and the fabric strengths were examined. It was shown that the nature Of the stitching between layers of woven fabric can have significant effects on the overall tensile strength.