Monitoring Damage Propagation in Glass Fiber Composites Using Carbon Nanofibers

Abstract

In this work, we report the potential use of novel carbon nanofibers (CNFs), dispersed during fabrication of glass fiber composites to monitor damage propagation under static loading. The use of CNFs enables a transformation of the typically non-conductive glass fiber composites into new fiber composites with appreciable electrical conductivity. The percolation limit of CNFs/epoxy nanocomposites was first quantified. The electromechanical responses of glass fiber composites fabricated using CNFs/epoxy nanocomposite were examined under static tension loads. The experimental observations showed a nonlinear change of electrical conductivity of glass fiber composites incorporating CNFs versus the stress level under static load. Microstructural investigations proved the ability of CNFs to alter the polymer matrix and to produce a new polymer nanocomposite with a connected nanofiber network with improved electrical properties and different mechanical properties compared with the neat epoxy. It is concluded that incorporating CNFs during fabrication of glass fiber composites can provide an innovative means of self-sensing that will allow damage propagation to be monitored in glass fiber composites.

Properties and mechanisms of self-sensing carbon nanofibers/epoxy composites for structural health monitoring

“…It is well established that the homogeneity of nanofibers dispersion into the polymer matrix is one of the most important factors affecting the nanocomposite's electrical and mechanical performance. Several dispersion methods were recommended in literature to avoid agglomeration and to obtain high percolation in the composites [3], [12], [35], [36]. In this paper, two methods, including mechanical stirring and ultrasonic treatment, were used to disperse CNFs.…”

Monitoring Moisture Damage Propagation in GFRP Composites Using Carbon Nanoparticles

“…In this study, we investigate the ability of carbon nanoparticles as carbon nano fibers (CNFs) and multi-walled carbon nanotubes (MWCNTs) to reduce moisture absorption of GFRP and to enable monitoring moisture damage in GFRP composites. Our hypothesis is based on our prior work [21] confirming the potential use of the CNFs to monitor mechanical damage propagation in GFRP composite. Here we examine the use of both CNFs and MWCNTs to monitor the propagation of moisture damage in GFRP.…”

“…This may be attributed to the effect of hydrolytic degradation of the epoxy network in the presence of ionic species in the water medium [56]. By comparing the spectra of dry coupons with the immersed ones, it can be noticed that the O–H band was shifted from ~3400 cm −1 toward 3340 cm −1 which is attributed to the fact that a hydrolytic degradation reaction causes the generation of more O–H groups in the polymer matrix and consequently changes the inter/intra molecular hydrogen bonding ratio which leads to redistribution in the arrangement of hydroxyl groups [21,57]. The effect of immersion time appears by relatively comparing the peak heights for the O–H band and also for the N–H band.…”

In-Line Nanostructuring of Glass Fibres Using Different Carbon Allotropes for Structural Health Monitoring Application

“…Another approach of localizing material damage is the use of printed conductive paths [11,12] or CNT-filled coatings [13] which are deposited on the top of a composite. Furthermore, due to the incorporated piezoresistive effect by filling the whole polymer matrix with electrically conductive fillers such as CNT [14], carbon nano fibres (CNF) [15,16], and graphene nanoplatelets (GNP) [17,18], an analysis of mechanical stresses in parts is also possible.…”