Damage characterization of nano-interleaved CFRP under static and fatigue loading

Abstract

The use of high strength-to-weight ratio-laminated fiber-reinforced composites is emerging in engineering sectors such as aerospace, marine and automotive to improve productivity. Nevertheless, delamination between the layers is a limiting factor for the wider application of laminated composites, as it reduces the stiffness and strengths of the structure. Previous studies have proven that ply interface nanofibrous fiber reinforcement has an effective influence on delamination resistance of laminated composite materials. This paper aims to investigate the effect of nanofiber ply interface reinforcement on mode I properties and failure responses when being subjected to static and fatigue loadings. For this purpose, virgin and nanomodified woven laminates were subjected to Double Cantilever Beam (DCB) experiments. Static and fatigue tests were performed in accordance with standards and the Acoustic Emissions (AE) were acquired during these tests. The results showed not only a 130% increase of delamination toughness for nanomodified specimens in the case of static loads, but also a relevant crack growth resistance in the case of fatigue loads. In addition, the AE permitted to relate these improvements to the different failure mechanisms occurring.