Delamination Suppression Using Electrospun Nanofiber Interleaves

Abstract

Delamination is a primary failure mode in laminated composite structures, reducing strength, stiffness, and structural integrity, particularly under interlaminar loading and impact conditions. Electrospun nanofiber interleaves have emerged as an effective strategy to suppress delamination by enhancing interlaminar fracture toughness, improving energy dissipation, and bridging cracks. This study investigates the effectiveness of electrospun nanofiber interleaves in suppressing delamination in fiber-reinforced polymer (FRP) laminates. Polyamide (PA), polyacrylonitrile (PAN), and polyvinylidene fluoride (PVDF) nanofibers were electrospun and introduced between plies of carbon fiber-reinforced epoxy laminates. Mode I and Mode II fracture toughness, interlaminar shear strength (ILSS), and impact resistance were evaluated. Fractography using SEM and micro-CT provided insight into crack bridging, fiber pull-out, and interlayer toughening mechanisms. Experimental results demonstrate significant improvement in delamination resistance, with Mode I fracture toughness increasing by up to 90% and Mode II toughness by 70% compared to baseline laminates. Cohesive zone modeling and finite element analysis captured crack propagation behavior and confirmed the role of nanofiber interleaves in delaying delamination initiation and growth. The findings provide a foundation for designing next generation composite structures with superior interlaminar durability for aerospace, automotive, and marine applications.