The Effect of Veil Type and Laminate Architecture on the Mechanical and Dynamic Performance of Aramid Fiber Interlayered Thermoplastic Veil/Epoxy Composites: A Comprehensive Evaluation

ABSTRACT This study systematically investigates the flexural behavior, dynamic vibration characteristics (natural frequency and damping ratio), viscoelastic properties, density, water absorption, porosity, and microstructure of thermoplastic veil‐interleaved aramid fiber/epoxy composites. Accordingly, composites fabricated with five thermoplastic veils, namely fine glass (FG), polyetherimide (PEI), polyimide (PI), polyetheretherketone (PEEK), and polyphenylene sulfide (PPS), together with two aramid layer arrangements (H and 2H configurations), were examined. The results show that veil type dominates the stiffness and viscoelastic response. The flexural strength from three‐point bending and the effective storage modulus () from free‐vibration analysis were used jointly to characterize the stiffness response. FG veils enhanced both the flexural strength and the storage modulus, acting predominantly as a stiffness‐reinforcing interlayer, whereas PEI, PI, and PEEK veils were the principal contributors to energy dissipation, with the highest damping ratios and loss factor (tan δ c ) values; PPS provided an intermediate balance. Aramid layer arrangement was a critical parameter controlling the damping ratio. FG specimens showed the lowest water absorption (0.59%) and porosity (0.7%), while PI and aramid specimens exhibited microstructural deficiencies. Overall, the study provides a first‐tier material screening, identifying candidate veil/architecture combinations that warrant further qualification before any definitive engineering‐application claim can be made.