Experimental and numerical investigations on effect of nanofabric wetting on mode-i fracture behavior of electrospun nanofabric interleaved glass/epoxy composites

Delamination is a major cause of failure in laminated composite materials due to the resin rich weaker interlaminar region. In recent years, electrospun nanofabrics are extensively researched as interleave for strengthening the interlaminar region. However, improvement in mechanical properties of the interlaminar region due to interleaving depends on proper wetting of nanofabrics. In this paper, we present a novel technique to achieve improved wetting of the nanofabric during manufacture of electrospun glass nanofabric interleaved glass/epoxy composites. Prior to interleaving in the fabric layup, the nanofabric was immersed in resin bath. The composite panels were manufactured using low cost, out of autoclave VARTM method. Nanofabric interleaved composites, with "resin bath immersed" nanofabric or "wet nanofabric" showed significant improvement in mode-I fracture toughness, as compared to pristine (non-interleaved) and "dry nanofabric" interleaved composites. In fact, composites laminates with "dry nanofabric" interleave showed degradation in fracture toughness, compared to pristine composites. In order to understand, the effect of "nanofabric wetting" on mode-I fracture behavior of nanofabric interleaved composites, numerical simulation model was developed using the finite element method. The results of the simulation model give useful insight into mechanism of nanoreinforcement on fracture behavior.