Influence Of Fiber Length Research Articles

The effect of carbon fiber length on the thermal expansion of fiber‐reinforced particulate hybrid composites

AbstractThermal expansion of materials is a critical factor influencing their dimensional stability. This study explores the regulation of thermal expansion in composite materials through the incorporation of carbon fibers and zirconium tungstate particles. The influence of fiber length on the thermal expansion behavior of these composites was investigated. The investigation reveal that the variation in the relative elongation ratio (dl/L0) of the carbon fiber‐reinforced zirconium tungstate composites is nonlinear, characterized by an initial increase, subsequent decrease, and a final resurgence. Notably, an increase in fiber length results in a mitigated rate of increase in the (dl/L0) ratio. Furthermore, composites fabricated with shorter fibers exhibit a higher coefficient of thermal expansion (CTE). Upon elevating the temperature to 250°C, the CTE for composites reinforced with 100 and 500 mesh carbon fibers escalate to 24.5 × 10−6/K and 74.6 × 10−6/K, respectively. These values represent an 8% and 116% enhancement relative to those measured at 50°C.Highlights The thermal expansion properties are improved by adding carbon fiber and ZrW2O8 nanoparticles. Utilizing fiber lengths ranging from 100 to 500 mesh effectively diminishes the CTE. The Cf‐ZrW2O8/9621 composite exhibits non‐linear behavior in its dl/L0 ratio. Within the range, longer fibers are more beneficial for reducing the CTE.

Inductive Heating of Ceramic Matrix Composites (CMC) for High-Temperature Applications.

The inductive heating of a CMC susceptor for industrial applications can generate very high process temperatures. Thus, the behavior of a silicon carbide-based matrix with carbon-fiber-reinforced carbon (C/C-SiC) as a susceptor is investigated. Specifically, the influence of fiber length and the distribution of carbon fibers in the composite were investigated to find out the best parameters for the most efficient heating. For a multi-factorial set of requirements with a combination of filling levels and fiber lengths, a theoretical correlation of the material structure can be used as part of a digital model. Multi-physical simulation was performed to study the behavior of an alternating magnetic field generated by an inducing coil. The simulation results were verified by practical tests. It is shown that the inductive heating of a C/C-SiC susceptor can reach very high temperatures in a particularly fast and efficient way without oxidizing if it is ensured that a silicon carbide-based matrix completely encloses the fibers.

Study on preparation and property of coir fiber reinforced epoxy resin composite geogrid

Based on the development and application of green composite building materials, this study prepared a coir fiber reinforced epoxy resin composite grid using coir fiber as the reinforcement material. Through tensile tests of a multi rib grid, the effects of coir fiber content, length, and rib spacing on the composite grid were studied. The results showed that with increase in the coir fiber content, the tensile yield force first increased and then decreased, reaching the maximum value at coir fiber content of 1%. When the coir fiber content exceeded 1%, the tensile properties of the composite grid were lower than that of pure epoxy resin. With the increase in the coir fiber length, the tensile yield force of composite grid also first increased and then decreased. At a fiber length of 1 cm, the maximum tensile yield force was obtained, which was 34.33% higher than that of pure epoxy resin grid. Compared with the influence of fiber length and content on the composite grid, the influence of rib spacing on the composite grid was more obvious. At a rib spacing of 1 cm, the tensile yield force reached its maximum.

Research on the flowback mechanism of fiber-controlled proppant based on fiber strength force

Fiber sand control is widely used on site due to its advantages such as easy operation, significant effects, and low cost. However, the mechanism of fiber control proppant flowback is currently unclear, and the main controlling factors affecting the critical flow velocity are not yet clear. There is a lack of relevant theoretical support to optimize the design of fiber sand control. This article uses composite material theory to analogically calculate the tensile strength of fiber-reinforced sand and friction reinforcement theory to analogically calculate the shear strength of fiber-reinforced sand. The relationship between fiber strength force and tensile strength and shear strength is proposed, combined with the different stress conditions of proppant particles before and after fracture closure, and a fiber-controlled proppant flowback strength model is established based on the force arm balance. The critical velocity of proppant was calculated and compared through the stability experiment of fiber-reinforced proppant filling layer, and the accuracy of the model was verified and the influencing factors were analyzed. The results show that the influence of tensile strength and shear strength on fiber strength at the early stage of fracture closure is 0.2 and 0.8, respectively, and that after fracture closure is 0.1 and 0.9, respectively. The critical velocity calculated by the model is basically consistent with the experimental results. The critical velocity is most affected by the particle size and closure pressure of proppant, followed by the amount of fiber, and the influence of fiber length and diameter is relatively small.

High-strength carbon fiber-reinforced polyether-ether-ketone composites with longer fiber retention length manufactured via screw extrusion-based 3D printing

The mechanical properties of 3D-printed carbon fiber-reinforced polymer composites play a pivotal role in engineering applications. However, the preparation of high-performance composites through material extrusion remains a great challenge. In this study, four fiber-reinforced polyether-ether-ketone (CF/PEEK) composites with varying fiber lengths were manufactured by a homemade screw extrusion 3D printer and evaluated for their application potential. A systematic exploration was conducted on the influence of fiber length and annealing on the mechanical performance of samples. The results demonstrated that increasing fiber length and annealing enhanced the tensile and flexural strengths of components while diminishing impact strength and ductility. With an average fiber retention length of 209 μm, the annealed parts displayed exceptional tensile and flexural strengths of 169.8 MPa and 223.3 MPa, respectively, marking a 143% and 88% improvement over unannealed pure PEEK. Longer fiber retention length, higher crystallinity, and fewer internal flaws contribute to the improved mechanical performance of the samples. This study provides a broader scope for the preparation and application of 3D-printed high-performance composites.

Thermal Performance, Microstructure Analysis and Strength Characterisation of Agro-Waste Reinforced Soil Materials

The use of raw-earth materials reinforced by natural fibres, i.e., livestock waste in the form of greasy wool, represents an eco-friendly alternative for a variety of construction applications. This proposal is based on the analysis of unfired adobe blocks stabilised with wool fibres for use as both structural and non-structural building materials. The influence of fibre length on the thermophysical and mechanical properties of the tested material was investigated. The thermal conductivity coefficient (λ) of raw-earth samples was assessed by following three different test setting procedures (T = 20 °C, and HR at 30%, 50%, and 70%), with the aim to evaluate the effects of different fibre lengths in the raw-earth mix. Samples reinforced by fibres 20 mm in length exhibited the lowest thermal conductivity coefficient (λ = 0.719 W/mK) obtained by a test reproducing typical indoor conditions within the Mediterranean area, i.e., T = 20 °C, and HR 50%. The best mechanical performance was exhibited by samples reinforced by fibres 40 mm in length, with a flexural and compression strength of 0.88 MPa and 2.97 MPa, respectively. The microstructure of these biocomposites was also examined with a scanning electron microscope (SEM) and an energy dispersive X-ray (EDX) to qualitatively evaluate the variation of thermal and mechanical properties due to the different adhesion among the fibres and the soil. The experimental data show good efficiency and a significant improvement in the behaviour of these materials compared to the control samples. The evaluation of the results, with the length of the fibres being the only variable of the analysed samples, allowed for the identification of the mix suitable for the best mechanical and thermal performances, depending on the final use of the material.

Flexural fracture parameters of polypropylene fiber reinforced geopolymer

Geopolymer concrete is an effective solution for widely limiting the negative environmental impacts of the cement manufacturing world. In this research, the polypropylene fibers (PP fiber) with various volume fractions, lengths, reinforcing index as well as water-binder ratios (WBR) were mixed into geopolymers to evaluate the effect on their FrT (fracture toughness). A total of 28 experimental groups of different polypropylene fiber geopolymers were considered. In the three-point bending fracture examination, the deformation and displacement fields of polypropylene fiber reinforced geopolymer (PPFRG) notched beams during the fracture process were observed through digital image correlation (DIC). The results show that, the fiber reinforcing index can be used to consider the influence of fiber length and fiber content. In increasing the reinforcing index, the FrT first increased, but after reaching the peak, it decreased. In terms of fracture properties, the PPFRG with a low WBR (0.35) is generally more significant than that of a high WBR (0.38). Comparing the PP fiber with the other fibers in literature, the more substantial toughness enhancement effect and better economy of PP fiber have been proved. Furthermore, this paper established a fracture toughness calculation model through regression analysis.

Design and tribological performance of short S-Glass fibre reinforced biocomposites on the influence of fibre length and concentration

Fibre-reinforced biocomposites usage has gained prominence over the past decade. Although higher fracture toughness was observed when fibres were added to biocomposites, material degradation could occur due to filler and fibre content intolerance in the biocomposite matrix. Optimisation of resin-fibre-filler ratios helps in increasing the tribological performance of high load-bearing applications. However, the tribological performance is less understood due to limited in-vitro studies on the effect of fibre microstructures. A comprehensive investigation of the reciprocating and rotary wear behaviour of different compositions was carried out by varying fibre (0%, 5%, 10% and 15%) to particulate filler (40%, 45%, 50%, and 55%) weight fractions. The investigation aimed to identify the optimal composition of fibre-reinforced biocomposites based on the in-vitro ball-on-disc reciprocating and rotary wear tests in the presence of modified Fusayama solution. The cross-sectional areas of wear tracks were analysed using laser microscopy and scanning electron microscopy techniques to assess the surface morphology and subsurface damage of the wear tracks on biocomposites and the antagonist. The numerical results were statistically analysed using two-way ANOVA followed by a posthoc Tukey’s test (p = 0.05). The results showed a combination of adhesive, abrasive and fatigue wear for all the tested Groups. The friction coefficient had a longer transient period for the 5 wt% and 10 wt% Groups. Based on the surface roughness, coefficient of friction, SEMs, specific wear rate, and ease of manufacturing, the threshold limit for fibre loading was found to be 10 wt%. The rotary test had a considerably lower specific wear rate compared to the reciprocating test. Fibre weight fraction was found to be the influencing factor of the abrasive wear behaviour compared to fibre length for the tested Groups.

Correlation of interfacial stress with the surface roughness of carbon fiber in composites by the improved shear-lag theory

ABSTRACT An improved shear-lag model is proposed in this article to study the effects of interface roughness and interfacial stiffness on the mechanical properties of a representative volume element (RVE). The surface roughness of the fiber is represented by grooves distributed around the fiber. The interfacial stiffness is introduced by the cohesive zone modeling (CZM) to study the nonideal adhesion interface. This paper also considered the influence of fiber length on stress transfer. The theoretical model was validated through numerical simulation considering both regularly and irregularly distributed grooves. The results show that the improved shear-lag model can describe the interfacial stress properties accurately. Furthermore, it is found that the influence of surface roughness varies for different interfacial stiffness. The proposed method and results can guide the design and analysis of interfacial modifications in carbon fiber composites.

Influence of fiber length and moisture content on sound and vibration characteristics of hemp/epoxy composites

Bio-composites have become increasingly popular as a substitute for synthetic fibers over the last decade due to their eco-friendly nature. To utilize them effectively in engineering applications, particularly in the automotive industry, a thorough understanding of the material properties is necessary. This experimental investigation focuses on exploring the vibration-damping and acoustic properties of fiber composites made from hemp natural fiber and epoxy resin. The study involved the preparation of composite specimens using both short and long fibers through a hand layup process. The natural frequency and damping ratio of the specimen were computed from time-domain experimental data. The sound absorption coefficient of fiber specimens was determined in the frequency range of 63 Hz to 6300 Hz by using the impedance tube technique. The analysis revealed that the pre-treatment of fiber and the use of long fiber rather than short fiber enhances the damping properties of hemp fiber composites. Immersion of specimens in water resulted in the degradation of damping properties. Acoustic tests clearly showed that the ageing process affected short-treated fiber composites more significantly when compared to long-treated fiber composites.

Influence of fiber length and comber noil extraction in long staple worsted spinning on eri silk yarn quality

The eri cocoons are open mouthed and as their silk filaments are discontinuous, these can only be used for spun yarn production. In this study, the effect of fiber length and comber noil extractions on yarn quality were evaluated. The significant impact of fiber length as well as first and second comber noil extraction was observed on yarn unevenness, imperfections, tenacity, breaking elongation and hairiness. With the aim of minimizing unevenness, imperfections and hairiness along with maximizing tenacity and breaking elongation of yarn; the fiber length and comber noil were optimized using Minitab 19 software. It was revealed that 150 mm fiber length can be set in the staple cutter during spinning preparatory for all yarn counts; 19% and 7% comber noil extractions are required for first and second combing, respectively, to produce 40 and 60 Nm yarns, whereas for 80 Nm yarn about 1% more noil extraction is needed in both combing processes. Principal component analysis depicted that both two comber noil contribute about 57% and fiber length of 43% on yarn quality. Regression equations from the response surface design of the experiment were derived for different yarn quality characteristics which exhibit a difference between actual and predicted values of below 10%.

Estimation of rheological percolation threshold and influence of fibre length on properties of polypropylene/sisal fibre composites having near critical fibre length

In this paper, the rheological percolation threshold and the hardness of Polypropylene/Sisal fibre (PP/SF) composites were correlated. Power law fit was implemented for the estimation of rheological percolation threshold. Further, the performance properties of PP/SF composites having near-critical length fibre (NCLF) and short fibre were investigated in terms of thermomechanical, rheological, and dynamic mechanical parameters. The Shore D hardness data revealed that the rheological percolation threshold of the prepared composites remained in the range of 20–30 wt% of sisal fibre. Moreover, sisal fibre had an undeniable impact on the dynamic mechanical properties of the prepared composites. Further, the rise in the onset degradation temperature by 40 °C proved the improvement in thermal stability of the prepared composites. It was also found that PP/SF composite having 20 wt% of near critical length fibre had properties equivalent to that of PP/SF composite having 40 wt% of short fibre (fibre length less then critical fibre length). • Correlation between Rheological Percolation threshold and Shore D hardness. • PP/SF composites having near critical length fibres. • Effect of fibre length on performance properties of PP/SF composites.

Dimensional influence of basalt fiber reinforcements on the consolidation behaviour of rice husk ash stabilized soils

The development of reinforcement techniques in soils with various fibers has been a common practice since the early days. Recently, fibers and materials considered waste are being used to develop sustainable solutions in designing new soil reinforcing and stabilizing materials. In this paper, an investigation has been carried out to evaluate the dimensional influence of basalt fiber on the compressibility and swelling of soils stabilized with rice husk ash (RHA) and cement. Incorporating a nominal dosage of basalt fibers into the soil–cement-RHA composite produces a strong composite with smart material properties. Specimen containing expansive clay soil, basalt fibers (lengths 3 mm, 6 mm, 12 mm), RHA (5%, 10%, and 15%), and cement (3%), in their specified combinations, were prepared and tested. The influence of fiber length and variation of RHA-cement content was quantified using the consolidation curves (compression curves and normalized compression curves), compression index, and swelling index, which provided a detailed behavioral modification upon consolidation. Scanning Electron Microscopy (SEM) and X-ray powder diffraction (XRD) were also used to examine the reconstituted soil structure and chemical components. It is demonstrated that a reconstituted clay soil combination of 12 mm basalt fibers, 5% RHA, and 3% cement, enhanced the ultimate yield pressures and the resistance to excessive swelling. This paper emphasized the projected responses during the loading and unloading phases on the specimen and discussed the consolidation characteristics of the newly reconstituted soil composites.

Flexural behavior evaluation and energy dissipation mechanisms of modified iron tailings powder incorporating cement and fibers subjected to freeze-thaw cycles

Waste iron tailings with cement-based inorganic binder is an economical and sustainable highway engineering base material, which is an effective way to reduce iron tailings inventory and affinity for engineering promotion. The flexural behavior considering the freeze-thaw action plays a crucial role for highway engineering base material. In this study, two types of fibers including polypropylene (PP) fiber and glass fiber were used to modify cement iron tailings powder (CITP), i.e., PPCITP or GCITP. Based on flexural tests, the influences of fiber length and freeze-thaw cycles on flexural behavior of modified CITPs were discussed. The results showed that the failure flexural strength of PPCITP reached the highest value at PP fiber length of 12 mm, while the flexural strength of GCITP presented a wavy downward trend with the increase of glass fiber length. The freeze-thaw cycle test results showed that the flexural strength of both PPCITP and GCITP decreased with the increase of freeze-thaw cycles, and the frost resistance of GCITP was better than that of PPCITP under the condition of the same volume of fibers. Then the single fiber pull-out test results implied that the interface action between glass fiber and CITP (G-CITP) was higher than that between PP fiber and CITP (PP-CITP) considering various curing ages and freeze-thaw cycles. Moreover, it is corroborated that PP fiber and glass fiber with length of 12 mm have the better reinforcement role in CITP specimens from the perspective of dissipative energy of fiber failure. Meanwhile, the dissipative energy results of both modified CITPs with fibers showed a downward trend with freeze-thaw cycles as a whole, and the dissipative energy of GCITP was higher than PPCITP at the specimen broken, which is consistent with the conclusion drawn in the single fiber pull-out test. The quantitative relationship models among dissipative energy, effective fiber length and freeze-thaw cycles of PPCITP and GCITP were further established, which could provide a reference for the large-scale production of waste iron tailings in highway engineering base materials.

Effect of Fiber Length and Chemical Treatment on Wear Rate of the Natural Reinforced Polymer

The influence of fiber length and treated chemically on wear properties by using jute fibers reinforcing in polymer-matrix composites (PMC) has been considered. From the results, it was found that The wear rate decreasing with increasing load from (78.6 -70.35)%, (65.6-59.16)% and (72.9-67.7)% for (5,10,15) KN load respectively that decreasing due to disintegrating the sample's surface under increasing loads. also, The wear rate decreases with increasing load from (78.6 -70.35) gm/mm (65.6-59.16)gm/mm and (72.9-67.7) gm/mm for (5,10,15) KN load respectively that decreasing due to disintegrating the sample's surface under increasing loads. also,The rate of wear decreases with an increase in the length of the fibers by (65%), due to the effect of fiber length that causes difficulty in separating between fibers from the polymeric material, which means that the material is resistant to collapse and also in the presence of a chemical in the processing, which causes a strong bond and good adhesion between the reinforcing material and the material The basis resulting from pitting caused by chemical treatment.

Study and compare the mechanical properties of bio fiber reinforced composites

This study aims to evaluate the result of experimental investigation carried out on mechanical properties and dynamic mechanical analysis over a range of temperature and five different frequencies of short banana fiber polyester composite. The effect of temperature on the storage modulus (E′), loss modulus (E″), and loss factor or damping efficiency (tan δ) is determined. Composites specimen is fabricated in random fiber orientation using to hand lay-up method by Influence of fiber length (10 mm) and weight percentage (5, 10, 15, 20 wt%). Studies revealed that increase in the fiber content will increase the Mechanical property and storage modulus (E′) and the maximum is given by the composites having a fiber loading of 20 wt% at all temperature ranges. The peak height of loss modulus (E″) and damping curves (tan δ) were lowered with respect to the fiber content. The properties were compared with neat polyester. In this work increasing fiber content increases the Mechanical property and storage modulus (E′) of the composite.

Evaluation of Wear Properties and Water Absorption Behavior of Banana and Sisal Fiber Reinforced Epoxy Hybrid Composites: Influence of Fiber Length

ABSTRACT The natural fiber composites are emerging as replacement materials in wide engineering fields. In this work, banana, sisal, and banana-sisal fibers of three different fiber lengths namely 3 mm, 5 mm, and 7 mm are used as reinforcements in the epoxy matrix. The composite samples are prepared by using the injection molding technique. Frictional and wear characteristics of the composites are evaluated under dry operating conditions with the parameters like applied load (15–35 N), sliding speed (300–500 rpm) for a duration of 15 mins. Water absorption characteristics are studied at an interval of 6 days for a duration of 120 days. The results indicate that the incorporation of fibers at different lengths influences frictional force, coefficient of friction and specific wear rate of the composites to an extent. Frictional force and specific wear rate are greater at higher loads. Banana-sisal hybrid fiber composites are showing amplified coefficient of friction and specific wear rate than other composites. Composites made of Sisal fibers (12.4%) are showing more resistance to water absorption than banana (21.5%) and banana-Sisal (15.4%) fibers. SEM images explores the wear characteristics of testing surface with presence of micro cutting, fiber breakage, voids, and debris.

Crosstalk characterization in homogeneous multicore fiber using discrete changes model under bidirectional propagation

Abstract For the first time, the discrete changes model has been explored for crosstalk estimation under the bidirectional propagation condition. Crosstalk characterization in homogeneous multicore fiber (MCF) has been discussed, with different crosstalk estimation methods, such as, conventional model for perfectly homogeneous core, discrete changes model for real homogeneous core, and propagation direction interleaving (PDI) approach for backward propagation. The forward crosstalk expression under bending and twisting conditions, derived by the authors, has been utilized to visualize the impact of fiber twisting over a wide range. Discrete changes model has been analyzed for backward crosstalk, in order to observe the XT behavior for deterministic bending and twisting effects. For the crosstalk analysis in bidirectional propagation, 12-core MCF has been used, with circular lattice and square lattice arrangements for single-mode propagation. Moreover, for optimization and crosstalk suppression, trench-assisted core and PDI technique have been used to obtain the significantly low crosstalk in limited cladding diameter of 200 µm. The influence of fiber length and wavelength has been exhibited on crosstalk performance. The worst crosstalk level, and relative spatial efficiency in these MCFs have been compared with recently reported works.

Effect of Incorporating Polyvinyl Alcohol Fiber on the Mechanical Properties of EICP-Treated Sand.

Enzyme-induced calcium carbonate precipitation (EICP) technology can improve the strength of treated soil. But it also leads to remarkable brittleness of the soil. This study used polyvinyl alcohol (PVA) fiber combined with EICP to solidify sand. Through the unconfined compressive strength (UCS) test, the effect of PVA fiber incorporation on the mechanical properties of EICP-solidified sand was investigated; the distribution of CaCO3 in the sample and the microstructure of fiber-reinforced EICP-treated sand were explored through the calcium carbonate content (CCC) test and microscopic experiment. Compared with the sand treated by EICP, the strength and stiffness of the sand reinforced by the fiber combined with EICP were greatly improved, and the ductility was also improved to a certain extent. However, the increase of CCC was extremely weak, and the inhomogeneity of CaCO3 distribution was enlarged; the influence of fiber length on the UCS and CCC of the treated sand was greater than that of the fiber content. The improvement of EICP-solidified sand by PVA fiber was mainly due to the formation of a “fiber–CaCO3–sand” spatial structure system through fiber bridging, not the increase of CCC.

Influences of fiber length and water film thickness on fresh properties of basalt fiber-reinforced mortar

Influences of fiber length and water film thickness on fresh properties of basalt fiber-reinforced mortar