Mode-I interlaminar fracture behaviour of nanoparticle modified epoxy/basalt fibre-reinforced laminates (original) (raw)
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Frattura ed Integrità Strutturale
The composite materials are normally made of reinforcements and resins. High-performance composites are generally termed hybrid composite materials. Generally, fiber-reinforced composite laminates are very weak in their out-of-plane properties, to address this issue unidirectional (UD) Glass laminates are prepared by modifying epoxy matrix using plasma-treated multi-walled carbon nanotubes (MWCNTs) and compared with low-cost micro fillers like Aluminum oxide (Al2O3) and Sodium Carbonate (Na2CO3) in the epoxy matrix. All these Nano and Micro fillers were loaded in the range of 0.5wt% to 2wt% in epoxy. The addition of these fillers in the epoxy matrix was found to be effective in increasing the out-of-plane load-bearing capacity of the composites as compared to plain Glass epoxy laminates. Also, the fracture toughness enhanced in the range of 20-26% and 14-17.5% under mode I and mode II loading respectively. Scanning electron microscopic analysis was done for delaminated glass laminat...
The transverse tensile properties, interlaminar shear strength (ILSS) and mode I and mode II interlaminar fracture toughness of carbon fibre/epoxy (CF/EP) laminates with 10 wt% and 20 wt% silica nanoparticles in matrix were investigated, and the influences of silica nanoparticle on those properties of CF/EP laminates were characterized. The transverse tensile properties and mode I interlaminar fracture toughness (G IC ) increased with an increase in nanosilica concentration in the matrix resins. However, ILSS and the mode II interlaminar fracture toughness (G IIC ) decreased with increasing nanosilica concentration, especially for the higher nanosilica concentration (20 wt%). The reduced G IIC value is attributed to two main competing mechanisms; one is the formation of zipper-like pattern associated with matrix microcracks aligned 45°ahead of the crack tip, while the other is the shear failure of matrix. The ratio of G IIC /G IC decreased with the concentration of silica nanoparticles, comparable with similar CF/EP laminates with dispersed CNTs in matrix. Fractographic studies showed that interfacial failure between carbon fibre and epoxy resin occurred in the neat epoxy laminate, whereas a combination of interfacial failure and matrix failure occurred in the nanosilica-modified epoxy laminates, especially those with a higher nanosilica concentration (20 wt%).
Polymers, 2021
Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites’ fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications.
2016
ARTICLE INFORMATION ABSTRACT Original Research Paper Received 13 January 2016 Accepted 04 February 2016 Available Online 02 March 2016 In this research, the influence of adding carbon nanotubes on the tensile and the mode I interlaminar fracture of glass-fiber-epoxy laminated composite has been experimentally studied. For this purpose, the hybrid glass-fiber-epoxy-nanotube laminated composites which have 18 fiber-glass plain-weave layers were manufactured by hand lay-up method. The epoxy resin system is made of Epon828 resin with Epikure F205 as the curing agent. The multi-walled carbon nanotube (MWCNTs) modified with hydroxide (-COOH) is also dispersed into the epoxy system as a reinforcement in a 0%, 0.1%, 0.5% and 1% ratio in weight with respect to the matrix. In addition, the tensile nano-resin and hybrid nanocomposite specimen were produced. The results of the tensile test of nano-matrixes indicate that the maximum change in Young's modulus, ultimate strength and fracture t...
EVALUATION OF INTERLAMINAR FRACTURE TOUGHNESS OF GLASS FIBER − EPOXY-MODIFIED COMPOSITE MATERIALS
Developing efficient wind mill blades with high toughness and good fatigue life is one of the main engineering challenges for wind energy sector globally. FRP is commonly used in aerospace, manufacturing of auto ancillary parts, marine, and construction industries. Large wind mill blades are made of glass fiber/epoxy composites to achieve high-specific stiffness, strength and good fracture toughness. While operating, the wind mill blades are subjected to significant stress. These composite blades fail due to fiber/matrix delamination and cracking. Significant technical advances can be achieved by adding nano clay with glass fiber/epoxy composite. Toughness test (mode I) to understand the interlaminar fracture conducted on the double cantilever beam (DCB) specimen reveals that the inclusion of nano clay can appreciably increase the fracture toughness of the glass fiber/epoxy composite.
Fibers
The present work is focused on improving mode I and mode II delamination resistance of glass/epoxy composite laminates (50 wt.% of glass fibers) with milled glass fibers, added in various amounts (2.5, 5, 7.5 and 10% of the epoxy weight). Including fillers in the interlayer enhances the delamination resistance by providing a bridging effect, therefore demanding additional energy to initiate the crack in the interlaminar domain, which results in turn in enhanced fracture toughness. The maximal increase of mode I and mode II fracture toughness and of flexural strength was obtained by the addition of 5% milled glass fiber. The mechanism observed suggests that crack propagation is stabilized even leading to its arrest/deflection, as a considerable amount of milled glass fiber filler was oriented transverse to the crack path. In contrast, at higher filler loading, tendency towards stress concentration grows due to local agglomeration and improper dispersion of excess fillers in inter/int...
Fracture and interlaminar properties of clay-modified epoxies and their glass reinforced laminates
Engineering Fracture Mechanics, 2012
The present work illustrates the experimental results of a project aiming to assess the benefits deriving from the matrix nanomodification of composite laminates made by vacuum infusion of woven glass fabrics. The following properties have been investigated: mode I fracture toughness and crack propagation resistance for neat and clay-modified epoxy, interlaminar shear strength, mode I delamination resistance for base and clay-modified epoxy laminates. Available results indicate a significant improvement in the fracture toughness and crack propagation threshold of clay-modified epoxy. However, due to the nanofiller morphology, the behaviour of clay-modified laminates is still almost comparable to that of the base laminates.
Journal of Materials Science, 2020
In this study, the effects of adding nanofillers to an epoxy resin (EP) used as a matrix in glass fibre-reinforced plastic (GFRP) composites have been investigated. Both 1D and 2D nanofillers were used, specifically (1) carbon nanotubes (CNTs), (2) few-layer graphene nanoplatelets (GNPs), as well as hybrid combinations of (3) CNTs and boron nitride nanosheets, and (4) GNPs and boron nitride nanotubes (BNNTs). Tensile tests have shown improvements in the transverse stiffness normal to the fibre direction of up to about 25% for the GFRPs using the ‘EP + CNT’ and the ‘EP + BNNT + GNP’ matrices, compared to the composites with the unmodified epoxy (‘EP’). Mode I and mode II fracture toughness tests were conducted using double cantilever beam (DCB) and end-notched flexure (ENF) tests, respectively. In the quasi-static mode I tests, the values of the initiation interlaminar fracture toughness, GtextICtextCG_{\text{IC}}^{\text{C}}GtextICtextCGICC, of the GFRP composites showed that the transfer of matrix to...
Composites Part A: Applied Science and Manufacturing, 2019
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Polymer-Plastics Technology and Materials, 2020
This review critically examines the recent developments in the use of carbon-based nanofillers as additional reinforcement to enhance the interlaminar properties of FRP composites. The low interlaminar strength of FRP composites results in delamination failure. The various nanoreinforcement strategies and their effect on fracture toughness, interlaminar shear strength (ILSS) and interlaminar fatigue are discussed in detail to prevent this delamination failure. Important findings on various factors that influence the interlaminar properties of multi-scale composites are presented by discussing various intrinsic and extrinsic toughening processes. Moreover, an overview of simulation techniques is provided to predict the delamination onset and propagation.