scholarly journals Fibre Bridging and Nozzle Clogging in 3D Printing of Discontinuous Carbon Fibre Reinforced Polymer Composites: Coupled CFD-DEM Modelling

2021 ◽  
Author(s):  
Hao Zhang ◽  
Lixing Zhang ◽  
Haoqi Zhang ◽  
Jiang Wu ◽  
Xizhong An ◽  
...  
Keyword(s):  
3D Printing ◽  
Polymer Matrix ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Length ◽  
Fibre Volume ◽  
Nozzle Clogging ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Abstract A coupled multiphase model based on computational fluid dynamics (CFD) and discrete element method (DEM) is developed to numerically investigate the extrusion-based 3D printing process of discontinuous carbon fibre reinforced polymer composites. Short carbon fibres are modelled as rigid bodies by clumping discrete spheres in DEM, while polymer matrix is treated as an incompressible Newtonian fluid in CFD. A fluid-particle interaction model is adopted to couple DEM and CFD and represent the dynamic fibre/matrix interaction. Collisions between fibres are considered naturally in DEM by using the Hertz-Mindlin contact law. The coupled CFD-DEM is validated, both qualitatively and quantitatively, against X-ray microtomography (µCT) experimental results for the T300/PA6 composite. Parametric study on various fibre lengths, fibre volume fraction and resin viscosity using the CFD-DEM model shows that the nozzle clogging tends to occur when the fibre length and/or the fibre volume fraction are increased. Use of a polymer matrix with a lower viscosity can be effective to eliminate the clogging issue when printing composites with relatively short fibres. The fibre length is dominating when long fibres are used and the clogging is largely independent on the viscosity of the polymer matrix. Finally, a potential solution of using a cone sleeve insert located above the shrinking region to address the nozzle clogging issue is proposed and numerically assessed.

scholarly journals Fibre bridging and nozzle clogging in 3D printing of discontinuous carbon fibre-reinforced polymer composites: coupled CFD-DEM modelling

2021 ◽  
Author(s):  
Hao Zhang ◽  
Lixing Zhang ◽  
Haoqi Zhang ◽  
Jiang Wu ◽  
Xizhong An ◽  
...  
Keyword(s):  
3D Printing ◽  
Polymer Matrix ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Length ◽  
Fibre Volume ◽  
Nozzle Clogging ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

AbstractA coupled multiphase model based on computational fluid dynamics (CFD) and discrete element method (DEM) is developed to numerically investigate the extrusion-based 3D printing process of discontinuous carbon fibre-reinforced polymer composites. Short carbon fibres are modelled as rigid bodies by clumping discrete spheres in DEM, while polymer matrix is treated as an incompressible Newtonian fluid in CFD. A fluid-particle interaction model is adopted to couple DEM and CFD and represent the dynamic fibre/matrix interaction. Collisions between fibres are considered naturally in DEM by using the Hertz-Mindlin contact law. The coupled CFD-DEM is validated, both qualitatively and quantitatively, against X-ray microtomography (μCT) experimental results for the T300/PA6 composite. Parametric study on various fibre lengths, fibre volume fraction and resin viscosity using the CFD-DEM model shows that the nozzle clogging tends to occur when the fibre length and/or the fibre volume fraction are increased. Use of a polymer matrix with a lower viscosity can be effective to eliminate the clogging issue when printing composites with relatively short fibres. The fibre length is dominating when long fibres are used and the clogging is largely independent on the viscosity of the polymer matrix. Finally, a potential solution of using a cone sleeve insert located above the shrinking region to address the nozzle clogging issue is proposed and numerically assessed.

Effect of CacO3 and Wood Flour Filler on the Compression Strength of Coconut (Coir) Fibre Reinforced Polymer (FRP) Composite

2007 ◽  
Vol 18-19 ◽  
pp. 249-251
Author(s):  
Anthony O. Inegbenebor ◽  
A.D. Ogbevire ◽  
A.I. Inegbenebor
Keyword(s):  
Compressive Strength ◽  
Volume Fraction ◽  
Wood Flour ◽  
Fibre Volume Fraction ◽  
Testing Machine ◽  
Fibre Volume ◽  
Coir Fibre ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Coconut Fibre

Compression test specimens were produced from the composite material of fibre reinforced polymer (FRP). These specimens were tested on the compressive testing machine. The results obtained showed that 5% coconut fibre volume fraction with 95% volume fraction of polypropylene matrix gave compressive strength value of 39.3 Mpa. However, it was observed that when 15% volume fraction of CaCO3 and wood flour filler each were added, the compressive strength increased from 39.3 Mpa to 53.3 Mpa and 39.3Mpa to 43.7Mpa respectively. This observation was discussed in respect of the two fillers.

Effect of fibre content on the mechanical properties of hemp fibre woven fabrics/polypropylene composite laminates

2021 ◽  
pp. 096739112110239
Author(s):  
Sheedev Antony ◽  
Abel Cherouat ◽  
Guillaume Montay
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Woven Fabrics ◽  
Fibre Content ◽  
Viscoelastic Behaviour ◽  
Hemp Fibre

Nowadays natural fibre composites have gained great significance as reinforcements in polymer matrix composites. Composite material based on a polymer matrix reinforced with natural fibres is extensively used in industry due to their biodegradability, recyclability, low density and high specific properties. A study has been carried out here to investigate the fibre volume fraction effect of hemp fibre woven fabrics/PolyPropylene (PP) composite laminates on the tensile properties and impact hammer impact test. Initially, composite sheets were fabricated by the thermal-compression process with desired number of fabric layers to obtain composite laminates with different fibre volume fraction. Uniaxial, shear and biaxial tensile tests were performed and mechanical properties were calculated. Impact hammer test was also carried out to estimate the frequency and damping parameters of stratified composite plates. Scanning Electron Microscope (SEM) analysis was performed to observe the matrix and fibre constituent defects. Hemp fabrics/PP composite laminates exhibits viscoelastic behaviour and as the fibre volume fraction increases, the viscoelastic behaviour decreases to elastic behaviour. Due to this, the tensile strength increases as the fibre content increases. On the other hand, the natural frequency increases and damping ratio decrease as the fibre volume fraction increases.

scholarly journals Comparison of Analytical Approaches Predicting the Compressive Strength of Fibre Reinforced Polymers

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2517 ◽  
Author(s):  
Christian Leopold ◽  
Sergej Harder ◽  
Timo Philipkowski ◽  
Wilfried Liebig ◽  
Bodo Fiedler
Keyword(s):  
Compressive Strength ◽  
Prediction Accuracy ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Experimental Results ◽  
Analytical Models ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Analytical Approaches

Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account. The variation in fibre diameter is smaller for CFRP. The experimental results show that CFRP has about 50% higher compressive strength than GFRP. The models exhibit significantly different results. In general, the analytical models are more precise for CFRP. Only one fibre kinking model’s prediction is in good agreement with the experimental results. This is in contrast to previous findings, where a combined modes model achieves the best prediction accuracy. However, in the original form, the combined modes model is not able to predict the compressive strength for GFRP and was adapted to address this issue. The fibre volume fraction is found to determine the dominating failure mechanisms under compression and thus has a high influence on the prediction accuracy of the various models.

Effect of nanofiller on fibre laser drilling quality of carbon fibre reinforced polymer composite laminates

2018 ◽  
Vol 233 (4) ◽  
pp. 857-870
Author(s):  
Dhiraj Kumar ◽  
Kalyan Kumar Singh
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fibre ◽  
Polymer Matrix ◽  
Composite Laminates ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Multi Walled Carbon Nanotubes ◽  
Fibre Reinforced Polymer ◽  
Walled Carbon Nanotubes

Laser machining of carbon fibre reinforced polymer composites is a challenging task due to a significant difference between physical and thermal properties of the constituent materials, i.e. polymer matrix and carbon fibres. This results in extended heat-affected zone (HAZ), taper kerf and poor surface finishing. This paper focuses on an investigation, attempting to minimise the divergence in the decomposition temperature of carbon fibres and epoxy resin by adding multi-walled carbon nanotubes in polymer matrix as a secondary reinforcement. High thermal conductivity of multi-walled carbon nanotubes increases the thermal diffusivity of polymer matrix, which in turn reduces the matrix recession. In addition, laser power and scan speed was also considered as an input parameter and their influence on output responses such as HAZ, taper angle and surface roughness has been studied. To analyse the effect of multi-walled carbon nanotubes on the resultant thermal damage, an innovative technique, i.e. scanning acoustic microscopy was used. This technique provides a ply-by-ply damage analysis. C-scans of the top and bottom surface of the machined holes in the composite were also carried out. Further, micrographs of the holes were taken to analyse the quality of the holes using field-emission scanning electron microscope. The obtained results indicated that HAZ, taper angle and surface roughness of holes decreased by ∼30%, ∼47% and ∼43%, respectively, with 1.5 wt% multi-walled carbon nanotubes doped carbon fibre reinforced polymer laminates, when compared with the results obtained from experiments with neat carbon fibre reinforced polymer composite laminates.

scholarly journals Method for the Microstructural Characterisation of Unidirectional Composite Tapes

2021 ◽  
Vol 5 (10) ◽  
pp. 275
Author(s):  
Nico Katuin ◽  
Daniël M. J. Peeters ◽  
Clemens A. Dransfeld
Keyword(s):  
Voronoi Tessellation ◽  
Unidirectional Composite ◽  
Fibre Volume ◽  
Cross Sectional ◽  
Reinforced Polymer ◽  
Novel Approach ◽  
The Matrix ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Microstructural Characterisation

The outstanding properties of carbon fibre-reinforced polymer composites are affected by the development of its microstructure during processing. This work presents a novel approach to identify microstructural features both along the tape thickness and through the thickness. Voronoi tessellation-based evaluation of the fibre volume content on cross-sectional micrographs, with consideration of the matrix boundary, is performed. The method is shown to be robust and is suitable to be automated. It has the potential to discriminate specific microstructural features and to relate them to processing behaviour removing the need for manufacturing trials.

EMI Shielding Effectiveness of Copper/Epoxy Composites

2005 ◽  
Vol 13 (7) ◽  
pp. 657-668 ◽  
Author(s):  
Robert C. Wetherhold ◽  
Joseph M. McManaman
Keyword(s):  
Volume Fraction ◽  
Surface Condition ◽  
Fibre Volume Fraction ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Fibre Volume ◽  
Shielding Effectiveness ◽  
Emi Shielding Effectiveness ◽  
Ni Powder ◽  
Phase Interference

Samples of shaped and treated copper (Cu) fibre/brittle matrix composites have been fabricated with a variety of fibre shapes, treatments, diameters, and powder inclusions and tested for shielding effectiveness (SE) using the ASTM standard D4935-99 method over the frequency range 200 to 1500 MHz. A small amount of nickel (Ni) powder was included in some specimens to evaluate the effect of magnetic permeability on SE. Most tests were conducted at constant (15 vol%, “v%”) fibre volume fraction. Results show that a smaller fibre diameter results in significant SE improvements. SE was also substantially improved by relatively minor fibre shaping (which changes along the fibre length) or by fine-scale roughening via chemical treatment. Addition of small amounts of Cu powder leads to major improvements in SE. Most of the improvements are presumably due to the establishment of conductive networks, although fibre shaping or treatment allows greater scattering and thus more internal reflections with attendant absorption. The smaller diameter fibres consistently gave better SE. When a continuous fibre mesh was used, high SE resulted, showing the dominance of fibre connectivity for such materials; the surface condition of the mesh is relatively unimportant. The improvements in SE can be achieved with essentially identical mechanical properties, leading to an effective multifunctional material, although most of the SE values achieved so far are modest. Ni powder results in overall improvement in SE as well as a cyclic dependence of SE on frequency, which indicates phase interference at a scale of particle size not previously seen.

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.

scholarly journals Characterisation of Artocarpus Heterophyllus Fibre Reinforced Composite

2018 ◽  
Vol 5 (2) ◽  
pp. 304-309
Author(s):  
Hoo Tien Nicholas Kuan
Keyword(s):  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Tensile Modulus ◽  
Natural Fibre ◽  
Fibre Volume ◽  
Artocarpus Heterophyllus ◽  
Paper Making ◽  
Sport Equipment ◽  
Fibre Reinforced Polymer ◽  
Press Method

Natural fibre reinforced polymer composite (NFRPC) has successfully replaced other synthetic fibre for applications in automobile, sport equipment, furniture, electrical appliances, etc. Artocarpus heterophyllus or jackfruit are mass produced in most South East Asia, but most of the parts other than the fruit would go to waste. In this study, Artocarpus heterophyllus fibre reinforced high density polyethylene (HDPE) composite was fabricated and tested for its mechanical properties, such as tensile and hardness properties. Artocarpus heterophyllus fibres were made into sheets using traditional paper making process, before being laminated with HDPE films using hot press method. Different volume fraction of fibre laminates were produced: 10%, 13%, 17% and 21%. The study shows that composite with 10%, 13% and 17% fibre volume fraction exhibits better tensile strength and hardness value than neat HDPE, while composites with 13%, 17% and 21% fibre volume fraction exhibit higher tensile modulus than neat HDPE. The optimum fibre content for the Artocarpus heterophyllus composite is 17%.

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