Effect of stitch density on the damage inhibition and compression strength after high-velocity impact of UHMWPE fiber composites

This paper investigates the effect of stitch density on the high-velocity impact damage inhibition and CAI (compression after impact) strength of UHMWPE (Ultra-High Molecular Weight Polyethylene) fiber composites. The damage response and compression behavior after impact were quantified and analyzed using CT scanning and DIC (Digital Image Correlation) techniques. The findings reveal that the delamination area of the composite plate with the stitch space of 1 cm reduces by 49.14 % compared to the unstitched sample, and exhibits a 73.05 % higher compressive load than the plate with a 4 cm stitch space. Notably, the 4 cm stitch composite plates demonstrate a significant advantage in energy absorption. However, the sparse stitch structure destroys the original structure inside the composite, resulting in a degradation of CAI performance. The study provides guidance for the practical design of composite materials with enhanced energy absorption and damage resistance.