Grading of Biofibres for Use in Natural Fibre Composites

2011 ◽  
Vol 410 ◽  
pp. 23-23
Author(s):  
A. Crosky ◽  
Mindy Loo ◽  
Mohd Zakaria ◽  
Paresh Parmar ◽  
Andrew Beehag ◽  
...  
Keyword(s):  
Mechanical Behaviour ◽  
Fibre Composite ◽  
Mass Density ◽  
Natural Fibre ◽  
Cross Sectional Area ◽  
Environmental Benefits ◽  
Natural Fibres ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fibre Composites

Natural fibres obtained from plant sources are attractive as a replacement for glass fibres in fibre reinforced plastic composites because of their environmental benefits. However, unlike synthetic fibres, natural plant fibres show considerable variability in their mechanical properties due to the effects of climate, soil quality, time of harvest, etc. Variability in properties of the fibres translates into variability in the properties of products made from natural fibre composites and this is a major obstacle to the more widespread use of these materials. One way to accommodate fibre variability would be to test the mechanical behaviour of samples from incoming batches of fibres and assign a grade to each batch, which could then be taken into account when the fibres are subsequently used to produce composite products. However, conventional methods of determining mechanical behaviour require test samples of constant cross-sectional area but, unfortunately, this is not the case for natural fibres which vary in shape, width and lumen size, from place to place along the fibre. Insight as to how to deal with such variability is provided from the textiles industry where strength is determined as a function of linear mass density rather than cross-sectional area. This paper examines the feasibility of using a similar approach for grading natural fibres for use in natural fibre composite products.

scholarly journals Sustainable and Renewable Bio-Based Natural Fibres and Its Application for 3D Printed Concrete: A Review

2020 ◽  
Vol 12 (24) ◽  
pp. 10485
Author(s):  
Salmabanu Luhar ◽  
Thadshajini Suntharalingam ◽  
Satheeskumar Navaratnam ◽  
Ismail Luhar ◽  
Julian Thamboo ◽  
...  
Keyword(s):  
Material Selection ◽  
New Technology ◽  
Real Life ◽  
Natural Fibre ◽  
Environmental Benefits ◽  
Natural Fibres ◽  
Conventional Concrete ◽  
Sustainable Building ◽  
Fibre Composites ◽  
3D Printed

The concept of sustainability and the utilization of renewable bio-based sources have gained prominent attention in the construction industry. Material selection in construction plays a significant role in design and manufacturing process of sustainable building construction. Several studies are being carried out worldwide to investigate the potential use of natural fibres as reinforcement in concrete with its noticeable environmental benefits and mechanical properties. 3D printed concrete (3DPC) is another emerging technology, which has been under-developed for the past decade. The integration of reinforcement is one of the major challenges in the application of this new technology in real-life scenario. Presently, artificial fibres have been used as a reinforcement material for this special printable concrete mixture. However, natural fibre composites have received significant attention by many 3DPC constructions due to their lightweight energy conservation and environmentally friendly nature. These benchmarking characteristics unlock the wider area of natural fibres into the composite sector and challenge the substitution of artificial fibres. Hence, this paper presents a comprehensive review on the current practice and advantages of natural fibres in conventional concrete construction. Subsequently, with a view to the future efficient 3DPC construction, the potentials of natural fibres such as eco-friendly, higher impact, thermal, structural, and fire performance over the artificial fibres were highlighted, and their applicability in 3DPC as composites was recommended.

scholarly journals Characterisation of Natural Fibres for Sustainable Discontinuous Fibre Composite Materials

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2129 ◽  
Author(s):  
Ali Kandemir ◽  
Thomas R. Pozegic ◽  
Ian Hamerton ◽  
Stephen J. Eichhorn ◽  
Marco L. Longana
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Material Selection ◽  
Fibre Composite ◽  
Single Fibre ◽  
Natural Fibre ◽  
Natural Fibres ◽  
Fibre Composites ◽  
Waste Flow ◽  
Mechanical Performances

Growing environmental concerns and stringent waste-flow regulations make the development of sustainable composites a current industrial necessity. Natural fibre reinforcements are derived from renewable resources and are both cheap and biodegradable. When they are produced using eco-friendly, low hazard processes, then they can be considered as a sustainable source of fibrous reinforcement. Furthermore, their specific mechanical properties are comparable to commonly used, non-environmentally friendly glass-fibres. In this study, four types of abundant natural fibres (jute, kenaf, curaua, and flax) are investigated as naturally-derived constituents for high performance composites. Physical, thermal, and mechanical properties of the natural fibres are examined to evaluate their suitability as discontinuous reinforcements whilst also generating a database for material selection. Single fibre tensile and microbond tests were performed to obtain stiffness, strength, elongation, and interfacial shear strength of the fibres with an epoxy resin. Moreover, the critical fibre lengths of the natural fibres, which are important for defining the mechanical performances of discontinuous and short fibre composites, were calculated for the purpose of possible processing of highly aligned discontinuous fibres. This study is informative regarding the selection of the type and length of natural fibres for the subsequent production of discontinuous fibre composites.

Costs and benefits of gas inside wood and its relationship with anatomical traits: a contrast between trees and lianas

2020 ◽  
Vol 40 (7) ◽  
pp. 856-868 ◽  
Author(s):  
Arildo Souza Dias ◽  
Rafael Silva Oliveira ◽  
Fernando Roberto Martins
Keyword(s):  
Wood Density ◽  
Tree Species ◽  
Mass Density ◽  
Vessel Diameter ◽  
Dry Mass ◽  
Cross Sectional Area ◽  
Gas Content ◽  
Comparative Approach ◽  
Sectional Area ◽  
Cross Sectional

Abstract Gas inside wood plays an important role in plant functioning, but there has been no study examining the adaptive nature of gas inside wood across plants differing in biomechanical demands. Using a comparative approach, we measured gas volumetric content, xylem’s anatomical traits and wood density of 15 tree and 16 liana species, to test whether gas content varies between these plant types strongly differing in their biomechanical demands. We asked (i) whether trees and lianas differ in gas content and (ii) how anatomical traits and wood density are related to gas content. Lianas had significantly less gas content in their branches compared with tree species. In tree species, gas content scaled positively with fiber, vessel and xylem cross-sectional area and fiber and vessel diameter, and negatively with dry-mass density. When pooling trees and lianas together, fiber cross-sectional area was the strongest predictor of gas content, with higher xylem cross-sectional area of fiber associated with higher gas content. In addition, we showed, through a simple analytical model, that gas inside wood increases the minimum branch diameter needed to prevent rupture, and this effect was stronger on trees compared with lianas. Our results support the view that gas inside wood plays an important role in the evolution of biomechanical functioning in different plant forms. Gas inside wood may also play an important role in physiological activities such as water transport, storage, photosynthesis and respiration, but it is still unknown whether these roles are or are not secondary to the mechanical support.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

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