Low‐Velocity Impact Response of Nacre‐Inspired E‐Glass/Epoxy Composites With Varying Platelet Sizes

ABSTRACT This study explores the low‐velocity impact behavior of nacre‐inspired biomimetic platelet composites (NIBPC), using low‐cost E‐glass fiber in chopped strand mat (CSM) form as reinforcement and epoxy resin as the matrix. Platelet‐shaped reinforcements of varying sizes (10, 15, 20, 25, and 30 mm) were precisely fabricated using a CO ₂ laser cutting process. Composite laminates were manufactured through compression molding, consisting of five layers: outer layers made of triaxial mat and inner layers formed with randomly oriented nacre‐like platelets. A monolithic nonbiomimetic laminate with five layers of CSM served as the reference. To evaluate the effect of platelet size on impact performance, drop‐weight impact tests were conducted under controlled conditions using specimens of identical dimensions. The results reveal that NIBPC laminates outperform the reference laminates in terms of peak impact force and energy absorption. The 20 mm platelet configuration demonstrated the highest performance, achieving an impact energy absorption of 43.73 J, an 8.78% improvement over the reference laminate's 40.2 J, and a peak resistance force of 8431.45 N, representing a 24.34% increase over the reference value of 6780.61 N. Both visual inspection at the macrolevel and SEM analysis at the microlevel reveal the progressive variation in damage severity with changes in platelet size. The specimen with a 20 mm platelet exhibited the least visible damage at the macroscale, along with minimal delamination and crack dimensions at the microscale. The alignment between the two inspection methods confirms the enhanced ability of the bioinspired laminate to resist deformation under low‐velocity impact loading. These findings highlight the critical role of platelet geometry in enhancing the toughness of bioinspired composites. The improved impact performance makes NIBPC materials promising candidates for automotive applications such as crash boxes, bumper beams, and engine bottom plates, where high energy absorption and durability are essential.