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.

scholarly journals A Study of the Interlaminar Fracture Toughness of Unidirectional Flax/Epoxy Composites

2020 ◽  
Vol 4 (2) ◽  
pp. 66 ◽  
Author(s):  
Yousef Saadati ◽  
Jean-Francois Chatelain ◽  
Gilbert Lebrun ◽  
Yves Beauchamp ◽  
Philippe Bocher ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Failure Modes ◽  
Glass Fibers ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture

Having environmental and economic advantages, flax fibers have been recognized as a potential replacement for glass fibers as reinforcement in epoxy composites for various applications. Its widening applications require employing failure criteria and analysis methods for engineering design, analysis, and optimization of this material. Among different failure modes, delamination is known as one of the earliest ones in laminated composites and needs to be studied in detail. However, the delamination characteristics of unidirectional (UD) flax/epoxy composites in pure Mode I has rarely been addressed, while Mode II and Mixed-mode I/II have never been addressed before. This work studies and evaluates the interlaminar fracture toughness and delamination behavior of UD flax/epoxy composite under Mode I, Mode II, and Mixed-mode I/II loading. The composites were tested following corresponding ASTM standards and fulfilled all the requirements. The interlaminar fracture toughness of the composite were determined and validated based on the specific characteristics of natural fibers. Considering the variation in the composite structure configuration and its effects, the results of interlaminar fracture toughness fit in the range of those reported for similar composites in the literature and provide a basis for the material properties of this composite.

scholarly journals Effect of sewage sludge ash filler on mode I and mode II interlaminar fracture toughness of S-glass/epoxy composites

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Mohamad Alsaadi 1,2 ◽  
Ahmet Erkliğ 2
Keyword(s):  
Fracture Toughness ◽  
Sewage Sludge ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Sewage Sludge Ash ◽  
Interlaminar Fracture ◽  
Glass Fiber Reinforced ◽  
Sludge Ash

In this study, the influence of sewage sludge ash (SSA) waste particle contents on the mechanical properties and interlaminar fracture toughness for mode I and mode II delamination of S-glass fiber reinforced epoxy composites were investigated. Composite laminate specimens for tensile, flexural double-cantilever beam (DCB) and end-notched flexure (ENF) tests were prepared and tested according to ASTM standards with 5, 10, 15 and 20 wt% SSA filled S-glass/epoxy composites. Properties improvement reasons was explained based on optical and scanning electron microscopy. The highest improvement in tensile and flexural strength was obtained with 10 wt% content of SSA. The highest mode I and mode II interlaminar fracture toughness’s were obtained with 15 wt% content of SSA. The mode I and mode II interlaminar fracture toughness’s improved by 33 and 63.6%, respectively, compared to the composite without SSA.

Influence of Temperature on Interlaminar Fracture Toughness of a Carbon Fiber-Epoxy Composite Material

2016 ◽  
Vol 1135 ◽  
pp. 35-51 ◽  
Author(s):  
Rita de Cássia Mendonça Sales ◽  
Bianca Lis Rossi Dias Endo ◽  
Maurício Vicente Donadon
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Mechanical Resistance ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Delamination Resistance ◽  
Different Temperatures ◽  
Influence Of Temperature On

Composite materials have been increasingly used in the aerospace industry for the manufacturing of structures, because of the associated properties of low weight and high mechanical resistance. On the other hand, they have low delamination resistance. This paper presents the results of an experimental study performed to obtain the values of interlaminar fracture toughness (G) of a laminate under three different temperatures, using 0º carbon-epoxy prepreg fabric plies and manufactured via Hand lay up cured in autoclave (HLUP). Double Cantilever Beam (DCB) tests were performed to evaluate mode I toughness, Four Point Bend End Notched Flexure (4ENF) for mode II and Mixed Mode Bending (MMB) for mixed mode I / mode II at -54°C, 25°C and 80°C. The data were collected and analyzed using a routine developed in Matlab®. Finally, the relation between GI and GII through the failure envelope and the temperature influence on the interlaminar fracture toughness was assessed.

Interlaminar fracture toughness of flax-epoxy composites

2016 ◽  
Vol 36 (2) ◽  
pp. 121-136 ◽  
Author(s):  
F Bensadoun ◽  
I Verpoest ◽  
AW Van Vuure
Keyword(s):  
Fracture Toughness ◽  
Epoxy Composite ◽  
Flax Fibre ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Brittle Polymer ◽  
Tensile Toughness

The purpose of this study was to determine the influence of fibre architectures on the interlaminar fracture toughness and tensile toughness of flax fibre epoxy composites. The fracture toughness was investigated for both Mode I (GIC) and Mode II (GIIC) for seven flax-epoxy architectures: one plain weave, two twill 2 × 2 weaves, a quasi-unidirectional and a unidirectional architecture, the UD’s being tested in both [0,90] and [90,0] composite lay-ups. The results of the Mode I and Mode II showed promising results of the flax-epoxy composite performance. The addition of flax fibre increases the GIC and GIIC of the composites over that of the unreinforced brittle polymer by at least two to three times. Further improvements are made with the use of woven textiles. The tensile toughness was found to be a good indicator of the capacity of a material to sustain perforation or non-perforation impact.

Effects of Thickness on Fracture Toughness of Carbon/Polyester Composite

2011 ◽  
Vol 471-472 ◽  
pp. 886-891
Author(s):  
Mohammad Hossein Heydari ◽  
Naghdali Choupani
Keyword(s):  
Fracture Toughness ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Mixed Mode ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Intensity Factors ◽  
Interlaminar Fracture ◽  
Polyester Composite

The aim of this paper is to evaluate interlaminar fracture toughness and non dimensional stress intensity factors of woven Carbon-Polyester composite based on numerical and experimental methods. A modified version of Arcan specimen was employed to conduct a mixed-mode fracture test using a special loading device. By changing the loading angle, α, from 0° to 90°, mode-I, mode-II and all mixed-mode data were created. The finite element analysis was performed with Abaqus software. The interaction j-integral was used to separate the mixed mode stress intensity factors and energy release rate at the crack tip under different loading conditions and different thickness of specimens. The results of fracture toughness tests revealed that the interlaminar fracture of composite is strong under the shearing-mode loading but weaker to the opening- mode loading. It can be seen that by increasing the thickness of the composite specimen, non dimensional stress intensity factors for pure mode I (α=0°) and pure mode II (α=90° ) loading conditions were decreased.

scholarly journals Studies on Mixed Mode Interlaminar Fracture Toughness of M55J/M18 Carbon/Epoxy Laminates

2000 ◽  
Vol 9 (5) ◽  
pp. 096369350000900 ◽  
Author(s):  
S. Jose ◽  
R. Ramesh Kumar ◽  
G. Venkateswara Rao ◽  
P. Sriram
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Fracture Criterion ◽  
Experimental Studies ◽  
Mode I ◽  
Mode Ii ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture ◽  
Delamination Fracture ◽  
Epoxy Material

Experimental studies are carried out to determine the interlaminar fracture toughness of unidirectional laminates made of M55J/M18 carbon/epoxy material under different mixed mode ratios ( G I/ G II). A mixed mode delamination fracture criterion using mixed mode bending specimens is developed. It is observed that when loading in mode I is predominant, G II has a considerable value but the opposite is not true when mode II is predominant.

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