Ballistic performance analysis of PBO fiber‐reinforced epoxy composites through resin matrix rigidity and toughness modulation

Abstract The rigidity and toughness of the resin matrix significantly influence the impact resistance of ballistic composites. However, the relationship between the properties of the resin matrix and the ballistic performance of the composites remains inadequately defined. In this study, the ballistic performance of composites with various matrix resins was investigated to assess how matrix toughness affects energy absorption. A series of epoxy resins exhibiting different rigidity and toughness were combined with PBO (poly‐p‐phenyl‐2,6‐benzobisoxazole) fibers, and their quasi‐static mechanical properties were evaluated to analyze their effectiveness in resisting ballistic impacts. In ballistic test, the brittle matrix composite demonstrated concentrated fiber breakage and localized damage, while the toughened matrix composite exhibited more dispersed damage characterized by reduced fiber breakage and minimal delamination, suggesting enhanced energy absorption via deformation within the matrix. Compared with the specific energy absorption value of the brittle matrix composite material, which is only 9.28 Jm²/kg, the specific energy absorption value of the tough matrix composite material has increased by 125% to 20.88 Jm²/kg. These findings underscore the critical role that matrix toughness plays in improving ballistic‐resistant performance by facilitating better energy distribution while mitigating fiber damage. Highlights Matrix toughness significantly enhances ballistic energy absorption in composites. Toughened matrix reduces fiber breakage and delamination under ballistic impact. Toughened matrix composite achieves a 125% higher specific energy absorption. Findings offer insights for designing high‐performance ballistic‐resistant materials.