The effects of auxeticity on the high-velocity impact response and damage characterization of CFRP composite laminates: a numerical evaluation

Purpose This research paper aims to examine the ballistic performance of carbon-fiber-reinforced polymer (CFRP) laminates with novel auxetic architectures having through-thickness and in-plane negative Poisson’s ratios under high-velocity impact (HVI), and compares it with conventional cross-ply configurations. Design/methodology/approach A progressive damage model is implemented to simulate fiber and matrix failure, and also interlaminar delamination, using Hashin–Puck and Chang–Chang criteria in a VUMAT subroutine. Performance metrics in terms of ballistic limit velocity, residual velocity and absorbed energy were analyzed quantitatively. Findings The through-thickness auxetic laminate showed the best ballistic performance: ballistic-limit approximately +4.6% versus cross-ply and +23% versus in-plane auxetic; at 115 m/s absorbed energy approximately+5.8% versus cross-ply and +27.8% versus in-plane auxetic. Residual projectile velocities were consistently lower. Originality/value Well-detailed study on the capability of novel composite layups to enhance CFRP laminate behavior to impact resistance (despite CFRPs having been extensively characterized regarding response in these conditions). The results point out the role of the through-thickness auxetic effect in enhancing the HVI resistance of composite laminates, bringing practical implications on the design of innovative and impact-resistant structures for aerospace, automotive and personal protection applications.