Evaluation of the impact response of textile composites

An evaluation of the impact damage resistance and impact damage tolerance of stitched and unstitched uniweaves, 2-D braids, and 3-D weaves was conducted. Uniweave laminates were tested at four thicknesses to determine the sensitivity of the tests to this parameter. Several braid and weave parameters were also varied to establish their velocity (large mass) impacts and then loaded in tension or compression to measure residual strength. Experimental results indicate that stitching significantly improves the uniweaves' damage resistance. The 2-D braids and 3-D weaves offered less damage resistance than the stitched materials. Stitching also improved the compression after impact (CAI) and tension after impact (TAI) strengths of the uniweave materials.