scholarly journals Fabrication and Characterization of Unidirectional Silk Fibre Composites

2011 ◽  
Vol 471-472 ◽  
pp. 20-25 ◽  
Author(s):  
Mansur Ahmed ◽  
Md. Saiful Islam ◽  
Qumrul Ahsan ◽  
Md Mainul Islam
Keyword(s):  
Volume Fraction ◽  
Flexural Modulus ◽  
Fibre Volume Fraction ◽  
Initial Study ◽  
Fibre Volume ◽  
Silk Fibre ◽  
Specific Strength ◽  
Pull Out ◽  
The Matrix ◽  
Strength And Stiffness

Natural fibres offer a number of benefits as reinforcement for synthetic polymers since they have high specific strength and stiffness, high impact strength, biodegradability etc. The aim of this study is to fabricate and determine the performance of unidirectional silk fibre reinforced polymer composites. In the present initial study, alkali treated silk fibres were incorporated as reinforcing agent, while a mixture of 20% maleic anhydride grafted polypropylene (MAPP) and commercial grade polypropylene (PP) was used as matrix element. The unidirectional composites were fabricated by using hot compression machine under specific pressure, temperature and varying fibre loading. Tensile, flexural, impact and hardness tests were carried out by varying silk fibre volume fraction. Composites containing 45% fibre volume fraction had higher tensile and flexural strength, Young’s modulus and flexural modulus compared to other fabricated composites including those with untreated silk fibres. SEM micrographs were taken to examine composite fracture surface and interfacial adhesion between silk fibre and the matrix. These micrographs suggested less fibre pull out and better interfacial bonding for 40% fibre reinforced composites.

scholarly journals Flexural Properties of Wet-Laid Hybrid Nonwoven Recycled Carbon and Flax Fibre Composites in Poly-Lactic Acid Matrix

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 120 ◽  
Author(s):  
Barbara Tse ◽  
Xueli Yu ◽  
Hugh Gong ◽  
Constantinos Soutis
Keyword(s):  
Lactic Acid ◽  
Carbon Fibre ◽  
Volume Fraction ◽  
Flexural Modulus ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Flax Fibre ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Flexural Properties

Recycling carbon fibre is crucial in the reduction of waste from the increasing use of carbon fibre reinforced composites in industry. The reclaimed fibres, however, are usually short and discontinuous as opposed to the continuous virgin carbon fibre. In this work, short recycled carbon fibres (rCF) were mixed with flax and poly-lactic acid (PLA) fibres acting as the matrix to form nonwoven mats through wet-laying. The mats were compression moulded to produce composites with different ratios of rCF and flax fibre in the PLA matrix. Their flexural behaviour was examined through three-point-bending tests, and their morphological properties were characterised with scanning electron and optical microscopes. Experimental data showed that the flexural properties increased with higher rCF content, with the maximum being a flexural modulus of approximately 14 GPa and flexural strength of 203 MPa with a fibre volume fraction of 75% rCF and 25% flax fibre. The intimate mixing of the fibres contributed to a lesser reduction of flexural properties when increasing the flax fibre content.

Mechanical Properties of Densified Untwisted Carbon Nanotube Yarn / Epoxy Composites

2015 ◽  
Author(s):  
Risa Yoshizaki ◽  
Kim Tae Sung ◽  
Atsushi Hosoi ◽  
Hiroyuki Kawada
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Polymer Matrix Composites ◽  
High Strength ◽  
Matrix Composites ◽  
Specific Strength ◽  
The Matrix ◽  
Cnt Arrays ◽  
Strength And Stiffness ◽  
Long Fibers

Carbon nanotubes (CNTs) have very high specific strength and stiffness. The excellent properties make it possible to enhance the mechanical properties of polymer matrix composites. However, it is difficult to use CNTs as the reinforcement of long fibers because of the limitation of CNT growth. In recent years, a method to spin yarns from CNT forests has developed. We have succeeded in manufacturing the unidirectional composites reinforced with the densified untwisted CNT yarns. The untwisted CNT yarns have been manufactured by drawing CNTs through a die from vertically aligned CNT arrays. In this study, the densified untwisted CNT yarns with a polymer treatment were fabricated. The tensile strength and the elastic modulus of the yarns were improved significantly by the treatment, and they were 1.9 GPa and 140 GPa, respectively. Moreover, the polymer treatment prevented the CNT yarns from swelling due to impregnation of the matrix resin. Finally, the high strength CNT yarn composites which have higher volume fraction than a conventional method were successfully fabricated.

Effects of fibre volume fraction on the stress transfer in fibre pull-out tests

Composites ◽  
1994 ◽  
Vol 25 (7) ◽  
pp. 470-475 ◽  
Author(s):  
Jang-Kyo Kim ◽  
Limin Zhou ◽  
S.J. Bryan ◽  
Yiu-Wing Mai
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Stress Transfer ◽  
Fibre Volume ◽  
Pull Out

The effects of interfacial debonding on the elastoplastic response of unidirectional silicon carbide—titanium composites

2010 ◽  
Vol 224 (2) ◽  
pp. 259-269 ◽  
Author(s):  
M J Mahmoodi ◽  
M M Aghdam ◽  
M Shakeri
Keyword(s):  
Volume Fraction ◽  
Yield Criterion ◽  
Fibre Volume Fraction ◽  
Three Dimensional ◽  
Fibre Volume ◽  
Interfacial Debonding ◽  
Successive Approximation Method ◽  
Interface Damage ◽  
The Matrix ◽  
Von Mises

A three-dimensional micromechanics-based analytical model is presented to investigate the effects of initiation and propagation of interface damage on the elastoplastic behaviour of unidirectional SiC—Ti metal matrix composites (MMCs) subjected to off-axis loading. Temperature-dependent properties are considered for the matrix. Manufacturing process thermal residual stress (RS) is also included in the model. The selected representative volume element consists of r× c unit cells in which a quarter of the fibre is surrounded by matrix sub-cells. The constant compliance interface model is used to model interfacial debonding and the successive approximation method together with von Mises yield criterion is used to obtain elastoplastic behaviour. Dominance mode of damage including fibre fracture, interfacial debonding, and matrix yielding and ultimate tensile strength of the SiC—Ti MMC are predicted for various loading directions. The effects of thermal RS and fibre volume fraction on the stress—strain response of the SiC—Ti MMC are studied. Results revealed that for more realistic predictions, both interface damage and thermal RS effects should be considered in the analysis. The contribution of interfacial debonding and thermal RS in the overall behaviour of the material is also investigated. Comparison between results of the presented model shows very good agreement with the finite-element micromechanical analysis and experiment for various off-axis angles.

Effect of Different Vacuum Pressure on the Tensile Properties of Sugar Palm Frond Fibre Reinforced Polyester Composites

2013 ◽  
Vol 701 ◽  
pp. 23-27
Author(s):  
S.A. Syed Azuan ◽  
M.M. Saufi ◽  
M.G. Azniah ◽  
J.M. Juraidi
Keyword(s):  
Tensile Properties ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Tensile Modulus ◽  
Fibre Volume ◽  
Vacuum Pressure ◽  
The Matrix ◽  
Polyester Composites ◽  
The One ◽  
Palm Frond

Sugar palm frond fibre has a potential to be as reinforcement in natural fibres reinforced polyester composites. This paper investigates the tensile properties of sugar palm frond fibre reinforced polyester composites. The sugar palm frond fibres were mixed with polyester composites at the 5 % fibre volume fraction with three different vacuum pressure of 5, 10 and 15 psi. The composites panels were fabricated using a vacuum bagging techniques. The tensile test was carried out in accordance to ASTM D638 respectively. The results showed that the vacuum pressure at 15 psi gave maximum value for tensile strength and tensile modulus. The results indicate that by increasing the vacuum pressure, it created a better bonding between fibre and the matrix. Minitab software was used to perform the one-way ANOVA analysis to measure the significant. From the analysis, there is a significant effect of vacuum pressure on the tensile properties.

scholarly journals 3D printing of composites: design parameters and flexural performance

2020 ◽  
Vol 26 (4) ◽  
pp. 699-706
Author(s):  
Feras Korkees ◽  
James Allenby ◽  
Peter Dorrington
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Design Parameters ◽  
Content Type ◽  
Flexural Performance ◽  
3D Printed ◽  
Strength And Stiffness

Purpose 3D printing of composites has a high degree of design freedom, which allows for the manufacture of complex shapes that cannot be achieved with conventional manufacturing processes. This paper aims to assess the design variables that might affect the mechanical properties of 3D-printed fibre-reinforced composites. Design/methodology/approach Markforged Mark-Two printers were used to manufacture samples using nylon 6 and carbon fibres. The effect of fibre volume fraction, fibre layer location and fibre orientation has been studied using three-point flexural testing. Findings The flexural strength and stiffness of the 3D-printed composites increased with increasing the fibre volume fraction. The flexural properties were altered by the position of the fibre layers. The highest strength and stiffness were observed with the reinforcement evenly distributed about the neutral axis of the sample. Moreover, unidirectional fibres provided the best flexural performance compared to the other orientations. 3D printed composites also showed various failure modes under bending loads. Originality/value Despite multiple studies available on 3D-printed composites, there does not seem to be a clear understanding and consensus on how the location of the fibre layers can affect the mechanical properties and printing versatility. Therefore, this study covered this design parameter and evaluated different locations in terms of mechanical properties and printing characteristics. This is to draw final conclusions on how 3D printing may be used to manufacture cost-effective, high-quality parts with excellent mechanical performance.

An Investigation into the Effect of Compaction on the Mechanical Performance of a 3D Reinforced Advanced Composite

2007 ◽  
Vol 15 (7) ◽  
pp. 535-543
Author(s):  
G. Stewart ◽  
A.T. McIlhagger ◽  
J.P. Quinn ◽  
S. King
Keyword(s):  
Mechanical Performance ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Conference Paper ◽  
Advanced Composite ◽  
Advanced Composites ◽  
Reinforced Composite ◽  
High Fibre ◽  
Strength And Stiffness

Industries such as aerospace, marine, automotive and construction are now embracing advanced composites processed using resin infusion techniques. These composites consist of complex fibrous reinforcements and polymeric matrices. They can offer lower costs and equivalent or greater performance than can composites produced via more expensive traditional techniques such as autoclaving. As a result they are gaining increasing acceptance. One such material is a 3D fibre reinforced composite which possesses superior strength and stiffness in the through-the-thickness (T-T-T) direction compared to 2D composites due to their T-T-T binder tows. However, due to the T-T-T binder it is harder to achieve the required high fibre volume fraction (Vf) for optimum performance. This paper investigates a 3D fibre reinforced composite and how its structure and mechanical properties are affected by increasing Vf. Some preliminary results in this paper were presented as a conference paper at IMC23 in August 2006.

The Strength of Fibres in All-Ceramic Composites

1986 ◽  
Vol 78 ◽  
Author(s):  
Kevin Kendall ◽  
N. Mcn. Alford ◽  
J. D. Birchall
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Ceramic Composites ◽  
Fibre Volume ◽  
Matrix Cracking ◽  
Fibre Strength ◽  
All Ceramic ◽  
The Matrix ◽  
Fibre Matrix

ABSTRACTWhen considering the strength of a fibre reinforced ceramic composite, it is often assumed that the fibres retain their full strength of several GPa after cracking of the weaker matrix. The strength of the composite after matrix cracking is then calculated by the rule of mixtures as the product of fibre volume fraction and fibre strength. This paper demonstrates that such a calculation is not consistent with the principles of fracture mechanics for an isolated fibre embedded in an elastic matrix of the same elastic modulus, because the strength of the fibre is much reduced by the stress concentration arising from the matrix crack. Experimental measurements of the strength of a glass fibre embedded in a brittle matrix support the theory. The case of a fibre in a matrix of different elastic modulus is also considered, together with the proDlem of cracking along the fibre-matrix interface.

Effect of polypropylene fibre on flexural properties of concrete composites containing fly ash and silica fume

2012 ◽  
Vol 226 (2) ◽  
pp. 177-181 ◽  
Author(s):  
P Zhang ◽  
Q Li ◽  
Z Sun
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
Modulus Of Elasticity ◽  
Volume Fraction ◽  
Flexural Modulus ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Polypropylene Fibre ◽  
Flexural Properties

The application of fly ash and silica fume in concrete composites by blending synchronously can improve the mechanical properties of concrete composites. However, the concrete composite becomes much brittle with the usage of fly ash and silica fume. Polypropylene fibre is often used to improve the ductility of concrete composites. This article discusses the effect of polypropylene fibre on the flexural properties of concrete composites containing fly ash and silica fume. Results reveal that the addition of polypropylene fibre can increase the flexural strength and decrease the flexural modulus of elasticity of the concrete composite containing fly ash and silica fume evidently. Furthermore, it is indicated that an increase in the fibre volume fraction leads to an increase in the flexural strength and a decrease in the flexural modulus of elasticity when the fibre volume fraction is not beyond 0.12 per cent. Polypropylene fibre seems to play an important role to improve the ductility of concrete composites containing fly ash and silica fume.

scholarly journals Review on Manufacture of Military Composite Helmet

2021 ◽  
Author(s):  
Yazhen Liang ◽  
Xiaogang Chen ◽  
Constantinos Soutis
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Structural Heterogeneity ◽  
Processing Parameters ◽  
Fibre Volume ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Protective Function ◽  
The Matrix ◽  
Manufacturing Technologies

AbstractDespite of the fact that more and more accessory devices are integrated to functionalize a ballistic helmet system, its core ballistic protective function needs to be improved with weight reduction was and still is the main course in engineering design. The two major generic classes of synthetic fibres for ballistic composites are Ultra High Molecular Weight Polyethylene (UHMWPE) fibre (0.97 g/cm3) and aramid fibre (1.44 g/cm3). In the area of military helmets, these fibres are constructed into different topologies, draping/forming into double-curvature geometric shape in multiple plies, serving as reinforcement for composite shell. The preforming ways influence the subsequent impregnation / solidification and curing step in manufacture, in terms of the fibre orientation and fibre volume fraction. The inherent structural heterogeneity thus leads to scatter in permeability and composite thickness, and have further impact in generating process-induced defects. During the processing, the fibre continuity without wrinkles, together with voids-free are determinative factors to a quality final part. The aim of this paper is to review the manufacturing technologies characterised by thermo-mechanical forming and Liquid Composite Moulding (LCM), relating their processing parameters respectively to the properties of reinforcements in one dimension (1D), two dimensions (2D) and three dimensions (3D), along with that of the matrix in dry or wet phase, interdependency of them are sought.

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