Mode I interlaminar fracture toughness of Nylon 66 nanofibrilmat interleaved carbon/epoxy laminates

Abstract

Carbon/epoxy laminates interleaved with laboratory scale electrospun Nylon 66 nanofibrilmat and spunbonded nonwoven mats were investigated. The effect of the nanoscale fibers on the fracture toughness of the composite under pure Mode I loading was evaluated. It was shown that the nanofibrilmat is responsible for a major interlaminar fracture toughness improvement, as high as 255–322%, compared to a noninterleaved carbon/epoxy reference laminate. We further studied the improvement mechanism of the electrospun nanofibrilmat compared to a commercial spunbonded nonwoven Nylon 66 mat. A combination of two interlayer fracture mechanisms responsible for the toughness improvement is suggested: the first is related to the high energy dissipated by bridged thermoplastic nanofibers and the second is attributed to the generation of a plastic zone near the crack tip. The interlaminar fracture mechanisms of both electrospun nanofibrilmat and the nonwoven mat interleaving was analyzed and discussed. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Nanofibre bridging as a toughening mechanism in carbon/epoxy composite laminates interleaved with electrospun polyamide nanofibrous veils

“…The effect of PA 6.6 nanofibres on woven laminates has been studied by Hamer et al [18] and Palazzetti et al [20,21]. Although Hamer et al report an increase in G Ic , only minor improvements and even decreases on both G Ic and G IIc are reported by Palazetti et al [18,20,21]. De Schoenmaker et al [14] state that G Ic increases slightly upon addition of PA 6 nanofibres in UD laminates.…”

“…However, these improvements in G Ic only occur during precracking or crack initiation, while G Ic was not affected or even decreased at further crack growth. The effect of PA 6.6 nanofibres on woven laminates has been studied by Hamer et al [18] and Palazzetti et al [20,21]. Although Hamer et al report an increase in G Ic , only minor improvements and even decreases on both G Ic and G IIc are reported by Palazetti et al [18,20,21].…”

Mode I and Mode II interlaminar fracture toughness of composite laminates interleaved with electrospun nanofibre veils

“…It has also been shown that certain nanofibre veils can be used to improve the compression after impact (CAI) [4], delamination resistance and the Mode I [5] and Mode II interlaminar fracture toughness (ILFT) of composites http://dx.doi.org/10.1016/j.compositesa.2015.01.028 1359-835X/Ó 2015 Elsevier Ltd. All rights reserved. [6][7][8][9][10]. Nanofibre veils have also been shown to improve the fatigue resistance [2,11] and vibration damping [12] properties of fibre reinforced composite materials.…”

Experimental investigation on the effects of carbon nanotubes on mode I interlaminar fracture toughness of laminated composites

“…Totally, in modified specimen, it was observed that the mode I and II fracture toughness have increased 17–120% respect to neat specimen. Hamer et al investigated the carbon/epoxy laminates interleaved with Nylon 66 nanofibrilmat and spunbonded nonwoven mats. The effects of the nanoscale fibers on the mode I fracture toughness of the composite specimens were evaluated.…”