scholarly journals Mode-I interlaminar fracture toughness of flax, glass and hybrid flax-glass fibre woven composites: Failure mechanism evaluation using acoustic emission analysis

2019 ◽  
Vol 75 ◽  
pp. 246-253 ◽  
Author(s):  
El Hadi Saidane ◽  
Daniel Scida ◽  
Marie-José Pac ◽  
Rezak Ayad
Keyword(s):  
Fracture Toughness ◽  
Acoustic Emission ◽  
Failure Mechanism ◽  
Glass Fibre ◽  
Woven Composites ◽  
Mode I ◽  
Interlaminar Fracture Toughness ◽  
Emission Analysis ◽  
Interlaminar Fracture ◽  
Acoustic Emission Analysis

scholarly journals On the extent of fracture toughness transfer from 1D/2D nanomodified epoxy matrices to glass fibre composites

2020 ◽  
Vol 55 (11) ◽  
pp. 4717-4733 ◽  
Author(s):  
Nadiim Domun ◽  
Keith R. Paton ◽  
Bamber R. K. Blackman ◽  
Cihan Kaboglu ◽  
Samireh Vahid ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Boron Nitride ◽  
Glass Fibre ◽  
Mode I ◽  
Interlaminar Fracture Toughness ◽  
Gfrp Composites ◽  
Interlaminar Fracture ◽  
Gfrp Composite ◽  
The Matrix ◽  
Matrix Toughness

AbstractIn 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, $$ G_{\text{IC}}^{\text{C}} $$GICC, of the GFRP composites showed that the transfer of matrix toughness to the corresponding GFRP composite is greatest for the GFRP composite with the GNPs in the matrix. Here, a coefficient of toughness transfer (CTT), defined as the ratio of mode I initiation interlaminar toughness for the composite to the bulk polymer matrix toughness, of 0.68 was recorded. The highest absolute values of the mode I interlaminar fracture toughness at crack initiation were achieved for the GFRP composites with the epoxy matrix modified with the hybrid combinations of nanofillers. The highest value of the CTT during steady-state crack propagation was ~ 2 for all the different types of GFRPs. Fractographic analysis of the composite surfaces from the DCB and ENF specimens showed that failure was by a combination of cohesive (through the matrix) and interfacial (along the fibre/matrix interface) modes, depending on the type of nanofillers used.

Nanowire reinforcement of woven composites for enhancing interlaminar fracture toughness

2016 ◽  
Vol 20 (1) ◽  
pp. 70-85 ◽  
Author(s):  
AG Castellanos ◽  
MS Islam ◽  
MAI Shuvo ◽  
Y Lin ◽  
P Prabhakar
Keyword(s):  
Fracture Toughness ◽  
Zinc Oxide ◽  
Textile Composites ◽  
Woven Composites ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Zinc Oxide Nanowires ◽  
Oxide Nanowires ◽  
Interlaminar Fracture

A novel technique to improve the Mode I and Mode II interlaminar fracture toughness of woven carbon-fiber polymer matrix composite face sheets using zinc oxide nanowires is proposed. Zinc oxide nanowires are directionally synthesized on dry carbon fabrics that are used to manufacture the laminate. The influence of zinc oxide nanowires on interlaminar fracture toughness is compared against regular interfaces using double cantilever beam and end-notched flexure tests to provide fracture toughness values. A significant improvement in the Mode I and Mode II interlaminar fracture toughness values is observed with zinc oxide nanowires. Therefore, zinc oxide nanowire interlaminar reinforcement has been proven to enhance the interlaminar fracture toughness of textile composites.

scholarly journals Mixed-Mode Interlaminar Fracture Toughness of Glass and Carbon Fibre Powder Epoxy Composites—For Design of Wind and Tidal Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2103
Author(s):  
Christophe Floreani ◽  
Colin Robert ◽  
Parvez Alam ◽  
Peter Davies ◽  
Conchúr M. Ó. Brádaigh
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibre ◽  
Composite Structures ◽  
Mixed Mode ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture

Powder epoxy composites have several advantages for the processing of large composite structures, including low exotherm, viscosity and material cost, as well as the ability to carry out separate melting and curing operations. This work studies the mode I and mixed-mode toughness, as well as the in-plane mechanical properties of unidirectional stitched glass and carbon fibre reinforced powder epoxy composites. The interlaminar fracture toughness is studied in pure mode I by performing Double Cantilever Beam tests and at 25% mode II, 50% mode II and 75% mode II by performing Mixed Mode Bending testing according to the ASTM D5528-13 test standard. The tensile and compressive properties are comparable to that of standard epoxy composites but both the mode I and mixed-mode toughness are shown to be significantly higher than that of other epoxy composites, even when comparing to toughened epoxies. The mixed-mode critical strain energy release rate as a function of the delamination mode ratio is also provided. This paper highlights the potential for powder epoxy composites in the manufacturing of structures where there is a risk of delamination.

Interlaminar fracture toughness and electromagnetic interference shielding of hybrid-stitched carbon fiber composites

2018 ◽  
Vol 37 (18) ◽  
pp. 1131-1141 ◽  
Author(s):  
Nisrin R Abdelal ◽  
Steven L Donaldson
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Electromagnetic Interference ◽  
Experimental Results ◽  
Mode I ◽  
Carbon Fiber Composites ◽  
Interlaminar Fracture Toughness ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Interlaminar Fracture

In the current study, the production of multifunctional hybrid-stitched composites with improved interlaminar fracture toughness and electromagnetic interference shielding effectiveness is reported. Unidirectional carbon fiber-epoxy composite laminates stitched with Kevlar, nylon, hybrid stitched with both Kevlar and nylon and unstitched were prepared using resin infusion process. Representative specimens from unstitched and stitched composites were tested using rectangular waveguide and Mode I double cantilever beam tests. The Mode I experimental results showed that composite stitched with Kevlar exhibited the highest crack initiation interlaminar fracture toughness (GIC-initiation), whereas composite stitched with nylon exhibited the highest maximum crack propagation interlaminar fracture toughness (GIC-maximum). The four-hybrid stitching patterns exhibited higher GIC-initiation than the unstitched and stitched with nylon composites and lower than stitched with Kevlar composite, whereas they had higher GIC-maximum than the unstitched and stitched with Kevlar composites, although lower than stitched with nylon composite. The electromagnetic shielding effectiveness experimental results showed that stitched composites exhibited improved shielding effectiveness compared to unstitched composites. For example, composite stitched with nylon had highest shielding effectiveness value of 52.17 dB compared by the composite stitched with Kevlar which had 40.6 dB. The four hybrid-stitched composites exhibited similar shielding effectiveness with an average value of 32.75 dB compared to the unstitched composite shielding effectiveness of 22.84 dB. The experimental results comply with the initial goal of this study to manufacture multifunctional hybrid stitching composites with combined properties between Kevlar and nylon-stitched composites.

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