Characterization of multi‐stitched woven nano composites under compression after low velocity impact (CALVI) load

The purpose of this research was to determine the compression after low velocity impact (CALVI) properties of multi‐stitched nano composite. It was obtained that the CALVI strength of the multi‐stitched nano composite was higher than that of the unstitched composites with or without the nanomaterial. In addition, stitching types (hand stitch or machine stitch) and the particle size of nanomaterial or micro material types were found to be important structural parameters for the multi‐stitched nano composites. The CALVI load applied on the multi‐stitched nano composite resulted in lateral damages close to the impacted indentation region. The failure modes of the damaged zone were local matrix‐fiber debonding and delamination, kinking, and local multiple matrix‐fiber breakages in the in‐plane and out‐of‐plane directions of the composite. Multi‐stitched nano composite showed large damaged areas but the out‐of‐plane layer delamination was confined to relatively small areas. Thus, multi‐stitching and nano particle addition enhanced the CALVI properties of the composite structures. POLYM. COMPOS., 39:3750–3764, 2018. © 2017 Society of Plastics Engineers