THE MECHANICAL-PROPERTIES OF NON-CRIMPED FABRIC-BASED COMPOSITES

The mechanical properties of composites prepared from two types of non -crimped fabric (NCF), namely biaxial, +/- 45-degrees and quadriaxial with a 0-degrees, +/- 45-degrees, 90-degrees, -45-degrees ply sequence , are examined as a function of fabric weight and compared with those of alternative composite forms. In general, the properties of NCF lami nates decrease slightly as the areal weight of the fabric increases. L aminates produced from biaxial fabrics exhibit superior properties for a given volume fraction of reinforcement than do laminates produced u sing woven rovings or continuous fibre prepregs, while quadriaxial NCF laminates have equivalent properties to woven roving laminates at cer tain orientations but, unlike woven roving laminates, retain their pro perties when rotated through 45-degrees. Biaxial NCFS loaded at 45-deg rees to the fibre and quadriaxial fabrics produce composites with supe rior properties to those predicted using finite element and laminate a nalysis for idealized laminates based on the same materials.