Tensile Properties Of Fibers Research Articles

Investigation of Single Fibre Tensile Properties of the Pineapple Leaf (PALF)

Recently, natural fibres composite is rigorously explored as alternative fibres due to the source depletion of petroleum. This research was focusing on pineapple leaf (PALF). The purpose of this research was to study the single fibre tensile properties of PALF. The single fibre tensile test was conducted via the universal testing machine following ASTM D3379 – 89 standards. The result shows that the Ultimate Tensile Strength (UTS) and Young’s Modulus of PALF were 141.093 MPa and 89.073 MPa, respectively. This research’s benefits include reducing agriculture waste of pineapple leaf, which is commonly being thrown out by the farmers when the fruits are harvested. It focuses not only on waste reduction but also on economic factors when other industries fully utilise the pineapple leaf.

Statistical modelling of tensile properties of natural fiber yarns considering probability distributions of fiber crimping and effective yarn elastic modulus

Unlike synthetic fiber yarns, due to limited fiber length, natural fiber yarns are made of twisted short natural fibers with various crimping status obeying certain probability distribution. Meanwhile, variations from fiber tensile properties and number of fibers in a yarn also result in scattering of mechanical properties of natural fiber yarns. An analytical model is proposed based on statistic theory to characterize the stochastic tensile properties of natural fiber yarns by defining crimp strain of fibers in a yarn and effective elastic modulus of yarns as random variables. The model is demonstrated on jute fiber yarns. Beta and normal probability distribution functions are selected to describe the statistical distributions of the crimp strain and effective elastic modulus, respectively. Parameters of the model are obtained from tensile testing results of jute yarns through inverse approach. The proposed model can provide accurate prediction bounds for tensile tests of jute yarns. Moreover, the proposed model is extended to predict the tensile response with progressive failure process of unidirectional fabric.

Characterization and Investigation of Tensile Properties of Kenaf Fiber Reinforced Polyester Composite Material

ABSTRACT The kenaf fibers were used to reinforce composites with two structures: nonwoven and bulk fibers and with treated and untreated kenaf fiber. A series of tensile tests were conducted on these composites. The use of kenaf fibers allows having composite with improved mechanical properties compared to pure polyester composite. This increase reaches 56.15% in strength and 137.85% in strain when varying the fiber weight ratio and the reinforcement structure. The interested results for both tensile strength and strain are obtained for nonwoven structure made by untreated fiber. The statistical study reveals that the most influencing parameter in tensile properties was the reinforcement weight ratio. The optimum composite was obtained when using a nonwoven structure made with untreated fiber with 11.10% fiber weight ratio.

Sericin from mulberry and non-mulberry silk using chemical-free degumming

In this study we report the extraction and characterization of sericin using water alone, from two non-mulberry silks - Antheraea assamensis (A. assamensis) and Philosamia ricini (P. ricini) compared with Bombyx mori (B. mori) silk. Degumming at 130 °C offered the highest sericin removal for A. assamensis; P. ricini had the lowest sericin removal among the varieties, because of its lower overall sericin content. Along with sericin degumming, fiber tensile properties were also reported. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of sericin revealed minimal sericin degradation even for degumming temperatures above 100 °C. The spectra from Fourier Transform Infrared Spectroscopy (FTIR) confirmed random coil motifs for B. mori sericin but a higher proportion of β-sheets in A. assamensis and P. ricini sericin which is likely to contribute to their lower water solubility. Thus, high temperature, water-based processing can be a potential approach for chemical- free degumming of silk fibers and to obtain high molecular weight sericin for different biomaterial applications.

SEM Characterization and Tensile Properties of Alkali Treated Single Coir Fiber with Drying Procedure Variation

This study has aimed to analyze the effect of alkali treatment and drying method on the surface morphology and tensile properties of single coir fibers. The treatments of the coir fibers have been configured on the concentration of alkali solution, the soaking period, and the drying method. Furthermore, they have been soaked in 2 wt% and 6 wt% sodium hydroxide solution at room temperature for 1- and 2-hours soaking periods. The drying procedures adopted have been air, oven, and sun-drying. Observations with a scanning electron microscope (SEM) show that the coir surface is coarser, especially on fibers treated with 6 wt% sodium hydroxide solution. The properties such as tensile strength and strain, as well as tensile modulus of the different samples have been measured. The results have showed that the treated coir fiber with the 2 wt% concentration alkali solution has lower tensile strength than the untreated one. The treated coir with 6 wt% sodium hydroxides has the most considerable tensile strength. The effect of the soaking period on the tensile properties has been influenced by the drying method. Therefore, the appropriate combination of the soaking period and the drying method increase single coir fibers tensile properties. Slow drying (air-drying) has generated better tensile properties than the fast method (oven and sun-drying).

Polymeric Coatings for AR-Glass Fibers in Cement-Based Matrices: Effect of Nanoclay on the Fiber-Matrix Interaction

Polymeric coatings are widely used to enhance the load bearing capacity and chemical durability of alkali-resistant glass (AR-glass) textile in cement-based composites. The contact zone between coated yarns and concrete matrix plays a major role to enable the stress transfer and has still to be improved for the full exploitation of the mechanical behavior of the composite. As a new approach, this paper studies how the addition of nanoclay particles in the polymer coating formulation can increase the chemical bond between organic coating and inorganic matrix. This includes the description of the water-based coating preparation by dispersing sodium montmorillonites, whereby the resulting coating nanostructure is characterized by X-ray diffraction and energy dispersive X-ray spectroscopy. Single glass fibers were treated by dip-coating. Atomic force microscopy was used to determine the surface roughness, and the effect on the fiber tensile properties was studied. Moreover, the morphological and chemical characteristics of the coatings were compared with the results obtained from single fiber pull-out (SFPO) tests. It was shown that the incorporation of nanoclays leads to increased interfacial shear strength arising from the ability of nanoclay particles to nucleate hydration products in the fiber-matrix contact zone.

Degradation of glass fiber reinforced polymer (GFRP) bars in concrete environment

Degradation of tensile, shear and flexure properties of glass fiber reinforced polymer (GFRP) bars is investigated in the paper. Glass fibre reinforced polymer bars, when used in structures exposed to aggressive environments, can significantly increase the lifetime, as compared to structures reinforced with conventional steel. However, the progress in utilization of GFRP bars in concrete structures is hampered due to limited information on durability of these materials. Since long-term durability data are not readily available, accelerated aging tests have been used in this research to study GFRP bar degradation. The bars were kept in a highly alkaline solution heated to 50, 60 and 70 °C for 1, 3 and 5 months, respectively, and after each immersion period, bars were taken out and tested in tension, shear and flexure. The experimental results show that immersion in high pH of the alkaline solution reduces the strength of the bars. The speed of degradation depends on the temperature of the solution. The degradation is then studied using the models for solution ingress into the GFRP bars. The conclusions proposed are that the shear test is a good indicator of the tensile strength degradation, bent bars deteriorate faster than straight bars, and smaller diameter bars deteriorate faster than larger diameter bars; finally, bars under flexural (tensile) strength deteriorate faster than those under direct tensile and shear strengths.

Extraction and Effects of Mechanical Characterization and Thermal Attributes of Jute, Prosopis Juliflora Bark and Kenaf Fibers Reinforced Bio Composites Used for Engineering Applications

In the present work tensile, flexural, impact and hardness properties of Prosopis juliflora bark (PJb), jute fiber (JF) and kenaf fiber (KF) reinforced polyester composites are expressed for the first time. The challenge in working with natural fiber composites (NFC) is the large variation in properties and characteristics. The properties of NFC to an enormous degree are impacted by the sort of fibers, a natural condition where the plant fibers are sourced and the kind of fiber treatments. In this experimental investigation JF as a base material, PJb and KF are filler materials. The weight percentage of JF has been maintained as constant and the remaining two fiber fillers were varied. To investigate the mechanical characteristics of tensile, flexural, impact and hardness tests were performed as per ASTM standard. The mechanical test outcomes exposed a reliable propensity of an expansion in the above mechanical credits to including natural fiber fillers. Fourier transform infrared spectroscopy (FTIR) is utilized to identify the chemical composition of NF and SEM analysis utilized for interfacial adhesion between the NF and polyester matrix. Thermal consistency/degradation of NF was identified through Thermogravimetric analysis (TGA).

Novel Insight into the Intricate Shape of Flax Fibre Lumen

Plant fibres and especially flax can be distinguished from most synthetic fibres by their intricate shape and intrinsic porosity called lumen, which is usually assumed to be tubular. However, the real shape appears more complex and thus might induce stress concentrations influencing the fibre performance. This study proposes a novel representation of flax fibre lumen and its variations along the fibre, an interpretation of its origin and effect on flax fibre tensile properties. This investigation was conducted at the crossroads of complementary characterization techniques: optical and scanning electron microscopy (SEM), high-resolution X-ray microtomography (µCT) and mechanical tests at the cell-wall and fibre scale by atomic force microscopy (AFM) in Peak-Force Quantitative Nano-Mechanical property mapping (PF-QNM) mode and micromechanical tensile testing. Converging results highlight the difficulty of drawing a single geometric reference for the lumen. AFM and optical microscopy depict central cavities of different sizes and shapes. Porosity contents, varying from 0.4 to 7.2%, are estimated by high-resolution µCT. Furthermore, variations of lumen size are reported along the fibres. This intricate lumen shape might originate from the cell wall thickening and cell death but particular attention should also be paid to the effects of post mortem processes such as drying, retting and mechanical extraction of the fibre as well as sample preparation. Finally, SEM observation following tensile testing demonstrates the combined effect of geometrical inhomogeneities such as defects and intricate lumen porosity to drive the failure of the fibre.

Effects of A, B, and S components on fiber length distribution, mechanical, and impact properties of carbon fiber/ABS composites produced by different processing methods

AbstractCarbon fiber/ABS composites with different acrylonitrile, butadiene, and styrene components were produced via extrusion/injection and long fiber thermoplastic (LFT)/injection molding processes, respectively. The effect of the components on fiber length distribution, tensile, flexural, impact, and dynamic mechanical properties of the composites was investigated. The properties of carbon fiber/ABS composites produced using 12 mm‐long LFT pellets were markedly higher than those produced using extruded pellets made with 12 mm‐long chopped carbon fibers. Uses of LFT pellets were preferable to enhancing the mechanical properties of carbon fiber/ABS composites. The tensile, flexural, and dynamic mechanical properties were increased in order of ABS750sw > ABS720 ≥ ABS780 > ABS740, whereas the impact strength was increased in order of ABS740 > ABS780 > ABS720 ≈ ABS750sw. Less carbon fiber damages and less carbon fiber length degradation upon LFT processing resulted in longer fiber length distribution and higher fiber aspect ratio in the composites with LFT pellets, indicating a beneficial reinforcing effect, which was responsible for the increased mechanical properties of ABS composites, particularly with ABS750sw. The results were agreed with each other, significantly depending on the A, B, and S components, being supported by fiber length distribution, fiber aspect ratio, and fracture surfaces.

Processing and determination of mechanical properties of Prosopis juliflora bark, banana and coconut fiber reinforced hybrid bio composites for an engineering field

In the present work tensile, flexural, impact and hardness properties of Prosopis juliflora bark (PJb), Banana fiber (Bf), and Coconut fiber (Cf) reinforced epoxy hybrid bio composites (untreated and alkali treated) are expressed for the first time. This experimental investigation Bf as a base material, PJb and Cf are filler materials. The weight percentage of Bf has been maintained as constant and the remaining two fiber fillers were varied. The untreated composite specimen shows the great enhancement of tensile attributes, flexural, and compression strength with an increase in coconut fiber loading. The better interlinking capability between the natural fiber composite (NFC) and an epoxy matrix is also responsible for effective resistance competence. Also, strong hydrogen bond formation due to the higher polarity of the epoxy matrix enhanced the flexural properties of the hybrid natural composites. Impact strength of untreated specimen has increased up to 25% wt. of Cf and Bf. Further addition of Cf and Bf showed a negative effect. Moreover, the hardness value of untreated specimens has gradually decreased with an increase in coconut fiber loading. The mechanical attributes of untreated composite specimens were compared with the treated composite specimen. The outcomes of alkali treated composite specimen show higher tensile attributes, flexural, compression, impact strength, and hardness compared with untreated composite specimens. Scanning electron microscope (SEM) observations on the fracture surface of composites showed that the surface modification of the fiber occurred and improved fiber-matrix adhesion. Fourier transform infrared (FTIR) and Atomic force microscopy (AFM) also used to observed the interfacial properties and characterization of natural fiber composites respectively.

Material Characterisation and Stratification of Conjunctival Epithelial Cells on Electrospun Poly(ε-Caprolactone) Fibres Loaded with Decellularised Tissue Matrices.

The conjunctiva, an under-researched yet incredibly important tissue, plays key roles in providing protection to the eye and maintaining homeostasis of its ocular surface. Multiple diseases can impair conjunctival function leading to severe consequences that require surgical intervention. Small conjunctival defects can be repaired relatively easily, but larger defects rely on tissue grafts which generally do not provide adequate healing. A tissue engineering approach involving a biomaterial substrate capable of supporting a stratified epithelium with embedded, mucin-secreting goblet cells offers a potential solution. As a first step, this study aimed to induce stratification of human conjunctival epithelial cells cultured on electrospun scaffolds composed from poly(ε-caprolactone) (PCL) and decellularised tissue matrix (small intestinal submucosa (SIS) or urinary bladder matrix (UBM)) and held at the air/liquid interface. Stratification, up to 5 cell layers, occurred more frequently on scaffolds containing PCL + UBM. Incorporation of these decellularised tissue matrices also impacted material properties, with significant changes occurring to their fibre diameter, tensile properties, and chemical composition throughout the scaffold structure compared to PCL alone. These matrix containing scaffolds warrant further long-term investigation as a potential advanced therapy medicinal product for conjunctiva repair and regeneration.

Double Edge Wedge Splitting Test to Characterize the Design Postcracking Parameters of Fiber-Reinforced Concrete Subjected to High Temperatures

AbstractThe determination of the postcrack tensile properties of steel fiber–reinforced concrete (SFRC) after exposure to elevated temperatures is a current methodological challenge. The objective ...

Influence of chemical treatment on the recycling of composites before pyrolysis

Recycling of carbon fibers is one of the upcoming global research topics in composite engineering. This work investigates the influence of chemical treatment on the recovery of carbon fibers from carbon fiber reinforced plastic before pyrolysis. The chemical pretreatment was achieved using a zinc chloride/ethanol solution. The pyrolysis process was conducted in a sliding furnace. The effect of such pre-treatment on thermal degradation behaviour was determined by a thermogravimetric analyser (TGA). An original sample was also investigated for benchmarking. After the thermal pyrolysis process, the fiber tensile properties were measured using a single fiber tester. The surface functional groups and graphitization degree recovered carbon fiber were characterized using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The surface morphology of recycled carbon fibers was investigated by SEM. Pristine carbon fibers were also included in the study for benchmarking. During the pyrolysis process, the devolatilisation temperature of the pre-impregnated prepregreduced by around 40-50°C and the peak temperature was 40-50°C lower compared to that of the original prepreg. The chemical pre-treatment process reduces the pyrolysis temperature compared to the conventional pyrolysis process. After pyrolysis in nitrogen with a small amount of air, loose carbon fibers were recovered, and their surface was clean. The similar surface functional groups and the decrease of degree of graphitization were detected on the recycled carbon fiber.

Effects of Fiber Reinforcements on the Strength of Shotcrete

Like concrete, Shotcrete poorly performs when subjected to tension; therefore, it experiences displacements and breaking when it is exposed to tensile loadings—adding fibers to concrete increases the ductility of Shotcrete. For this reason, two shotcrete mixes were prepared, plain, and reinforced with fibers (Fiber Reinforced Shotcrete, FRS). The results were looked at and recorded. Shotcrete with a strength of more than 35 MPa were designed and prepared. Steel and polypropylene fibers of different weights and shapes are added to Shotcrete. After adding fibers to Shotcrete, Shotcrete with fascinating properties is produced after testing the samples for 7 and 28 days. The results stated that the tensile and compressive strength of Shotcrete enhanced with additional fibers. Shotcrete has indistinguishable properties compared to concrete, and adding of polypropylene fibers up-to 3kg/m3 disclosed a nearly 20% rise in the compressive strength of Shotcrete. The compressive strength diminished with an increase in the quantity of fiber past 3kg/m3. The tensile and flexural properties of Polypropylene Fiber Reinforced Shotcrete (PFRS) continued expanding with higher fiber quantity. Similarly, the compressive, tensile, and flexure strength of Shotcrete increased with an increase in the number of steel fibers.

Fiber extraction and mechanical properties of Agave Americana/Kenaf fiber reinforced hybrid epoxy composite

The present work investigates the fiber extraction, tensile and flexural properties of agave American/kenaf fibers reinforced epoxy Hybrid composites. The fibers length are varied from 1 cm to 4 cm with varying the relative fiber weight fraction (Wf) such as 10, 15, 20 and 25% respectively. Fibers were extracted manually by water retting process. The random mixed fibers reinforced hybrid composites were prepared by handy layup method with compression moulding process. Scanning Electron Microscopy was employed for studying the microstructure of the specimen. Specimens were cut and tested by following ASTM standard. The experimental analysis has shown that fiber length of 3 cm having 20% Wf yields the best results for tensile and flexural strength.

Characterization of Cellulosic Leaf Fiber from the Typha Angustifolia Plant

ABSTRACT Typha leaves are a rich source of fiber cables and these fibers can also be extracted by chemical retting method and these are easily bio-degradable, and eco-friendly. The main objective of present work is to assess the fiber characteristics such as FTIR, XRD, TGA, SEM, and single fiber tensile properties by varying fiber extraction parameters. In the retting process, IR peaks clearly shows that there was a removal nonfibrous material (NFM). Using X-ray diffraction technique 67.61% crystallinity with a crystallinity index of 0.521 was observed. Fiber tips of SEM images confirm that by increase in chemical concentration and treatment time, there was more removal of NFM and fibrillation found. For the fiber extraction mainly two treatment particulars were varied i.e. sodium hydroxide (10, 20, and 30 gpl) and time (3, 4, 5, and 6 h). Out of various retting conditions, at 20 gpl with 4 and 5 h treatment time shows an excellent tensile strength of single fiber, i.e. 125 Mpa and 179.82 Mpa and 30 gpl with 4 hrs and 5 h observed moderate strength, i.e. 106.03 Mpa and 122.69 Mpa respectively.

Investigating the efficacy of machine learning tools in modeling the continuous stabilization and carbonization process and predicting carbon fiber properties

Carbon fiber reinforced composites are finding increased usage in a wide variety of applications, ranging from aerospace to energy harvesting to sporting goods and more. Carbon fiber manufacturing is an extremely time- and cost-intensive process with more than 70 processing variables. To better understand the processing-structure-property relationships and accelerate the improvement in carbon fiber mechanical properties, the integration of machine learning (ML) and experimental techniques is critical. The goal of this work is to investigate the use of ML models to map precursor information and carbonization process parameters to mechanical properties -- specifically, tensile strength and tensile modulus -- of carbon fibers. The experimental data consisted of 600 distinct points with 31 features. Four ML models were investigated viz. support vector regression (SVR), multi-layered perceptron (MLP) neural network, gradient boosted regression trees (GBRT), and recurrent neural network (RNN). The results indicate that ML can be used to approximate the underlying function describing the effect of the manufacturing process parameters on the carbon fiber tensile properties, with the RNN model outperforming all other models under consideration (R2 scores of 0.85 and 0.67 for tensile strength and tensile modulus, respectively).

Tensile and flexural properties of biodegradable jute fiber reinforced poly lactic acid composites

Abstract Several countries applied stringent regulations with respect to use of non-biodegradable products. Presently almost all fiber composite materials used in building and automobile industry are made from synthetic fibers and matrices. Disposable of these materials in landfill increases the burden on environment. In the present work, an attempt has been to develop biodegradable composite material and thus reduce the environmental concerns. Jute fiber is used as reinforcement and biodegradable poly lactic acid (PLA) as matrix in the preparation of biodegradable composites. Compression moulding method was adopted in the preparation of jutefiber reinforced PLA biodegradable composites. The Jute fiber reinforced PLA composites at four levels of loading (5, 10, 15 and 20 wt%) were utilized to conduct tensile test, and flexural test. The Tensile strength and flexural strength of PLA composite with jute fiber at 15% fiber loading was about 25% and 116% higher than the plain PLA respectively. The tensile modulus and flexural modulus of the jute/PLA composite at 15% fiber loading was 1.55 and 1.87 times that of plain PLA respectively. There is a significant change in the tensile and flexural properties of PLA when reinforced with jute fibers. Further, tensile and flexural failure modes of tested samples have been discussed.

The Longitudinal and Transverse Tensile Properties of Unidirectional and Bidirectional Bamboo Fiber Reinforced Composites

Alkali treatment on bamboo fibers were reported to improve the interface strength with epoxy resin as formed to a composite. In order to reduce the process time of alkali treatment, bamboo fibers were treated in alkali with different concentrations under the room temperature. The alkali treatment process for the bamboo fibers, which results in a higher tensile strength, was used for the subsequent studies. Unidirectional and bidirectional BF preforms were constructed in our laboratory. The unidirectional (UD) and bidirectional (BD) BF/EP composites were fabricated using the bamboo fibers treated with the selected BF alkali treatment process. Tensile properties were measured in both the longitudinal and transverse directions for the UD and BD BF/EP composites with different fiber volume fractions. The UD BF/EP composite has good reinforcement effect in the fiber direction and the tensile strength is compatible to the reported results. However, the transverse strength of UD composites is weaker than the pure epoxy. For BD BF/EP composites, tensile strengths in both the longitudinal and transverse directions all show some improvement as compared to the pure epoxy.