Understanding aramid pulp reinforcement ratios’ effect on low-velocity impact response of woven CFRP composites

This study evaluates the impact response and damage tolerance of carbon fiber-reinforced polymer (CFRP) composites with varying Aramid pulp reinforcement ratios subjected to low-velocity impact (LVI) at an energy level of 5 J. Pristine (unreinforced) and reinforced samples with 1X, 2X, and 4X Aramid pulp ratios were analyzed through drop-weight impact tests, flexural tests, and micro-CT scans. Results indicate that increasing reinforcement enhances energy absorption and maximum displacement but decreases peak force due to improved load distribution via delamination and matrix cracking. While 4X reinforced samples exhibit the highest energy absorption, they also show the most significant internal damage, including extensive delamination, void formation, and intralaminar failure. Flexural behavior reveals a decreased in stiffness and strength with higher reinforcement levels, which is attributed to weak fiber-matrix adhesion and resin-rich zones. Optimal reinforcement was observed at 2X, where flexural strain peaked due to effective crack bridging. Excessive reinforcement led to agglomeration effects, exacerbating void formation and structural weakening. The findings underscore the importance of optimizing reinforcement ratios and ensuring uniform dispersion to balance between energy dissipation and mechanical performance in CFRP laminates.