Cohesive zone modelling of delamination response of a composite laminate with interleaved nylon 6,6 nanofibres

Abstract

This work simulates numerically Double Cantilever Beam and End Notched Flexure experiments on Carbon Fibre Epoxy Resin specimens that have been performed by some of the authors in a previous work. Specimens have been nanomodified by interleaving plies with a layer of electrospun nanofibres in the delaminated interface. Eight different configurations of nanofibres have been used as interleave, for a total of 9 configurations (8 nanomodified plus the virgin one) to be simulated for both kind of tests to identify the cohesive zone parameters corresponding to the effect of nanofibre diameter, nanolayer thickness and nanofibre orientation on the delamination behaviour of the composite. Results showed that a bilinear damage law is necessary for almost all nanomodified configurations, and presented a clear relationship between nanomat layer parameters and the cohesive energy of the interface

Development and fracture toughness characterization of a nylon nanomat epoxy adhesive reinforcement

“…Since electrospinning provides a simple and versatile method for generating nanofibres, composite laminates modified by integrating electrospun nanofibres have been investigated several times during the last decade (see Zucchelli et al 11 ). In Palazzetti et al, 12 Moroni et al, 13 and Giuliese et al, 14 it was shown that the interleaving of a nanomat between adjacent plies yields a ply-to-ply bridging effect that increases the delamination strength of the composite laminate. Fracture toughness improvements up to 156 and 69% for Mode I and Mode II, respectively, were demonstrated by Beckermann and Pickering 15 in the case of unidirectional (UD) carbon/ epoxy composite laminates.…”

Electrospun nanofibers as reinforcement for composite laminates materials – A review

“…The main issues with the use of CNT and CNF are linked to health dangerousness [85] and difficulties in mixing and homogenizing with the matrix [86]. Authors considered out of the scope of this literature, and therefore did not treat, studies on nanofibers embedded in pure matrix [60,[87][88][89][90][91][92][93][94], on the single nanofiber [95][96][97][98], and on numerical simulations of nanomodified composites [65,[99][100][101][102].…”

Influence of electrospun nanofibers on the interlaminar properties of unidirectional epoxy resin/glass fiber composite laminates

“…Numerical simulations presented in [33,34] show that at any instant of time, the amount of nanofibers involved in the loading process is much higher during a Mode II test than during a Mode I, significantly increasing the reinforcement effect. It is due to the load direction: during Mode I tests, the two interfaces are opened and the stress is concentrated on the crack tip, involving a small portion of material and thus of nanofibers.…”