Fiber Strength Research Articles

Experimental investigation on impact strength of hybrid fibre reinforced concrete containing steel and polypropylene

Experimental investigation on impact strength of hybrid fibre reinforced concrete containing steel and polypropylene

An effect of retting process and extraction methods on physical and mechanical properties of areca nut fibers

PurposeThe purpose of the project is to explore the biosoftening of raw areca nut fibers using two different biological retting methods and assess their impact on fiber properties for improved spinning. The study aims to contribute to the fashion industry’s shift toward sustainability.Design/methodology/approachThe project involves collecting raw brown areca shells, subjecting them to two retting methods (stagnant water retting and changing water daily retting) and then extracting and drying the fibers. Various physical and chemical properties of the fibers are measured to evaluate their suitability for spinning.FindingsThe stagnant water retting method, especially the fibers obtained on the second day, showed improved properties in terms of fiber strength, elongation, fineness and cellulose content, making them suitable for spinning applications. The method also resulted in better moisture regain.Research limitations/implicationsThe study focused on two retting methods and a limited timeframe. Further research could explore additional techniques and durations. The labor-intensive nature of the daily changing water retting method may have implications for scalability.Practical implicationsThe project demonstrates a cost-effective and sustainable method for converting agricultural waste (areca nut husks) into valuable fibers suitable for various end users.Social implicationsThe research supports the fashion industry’s sustainability efforts by promoting the use of eco-friendly natural fibers, potentially benefiting rural farming communities.Originality/valueThe project highlights the innovative use of areca nut fibers and their potential to contribute to sustainable fashion. The stagnant water retting method is presented as a reliable and effective approach for improving fiber properties. Additionally, all fiber testing was exclusively conducted at the South India Textile Research Association (SITRA), with sponsorship from the industry and support from the Ministry of Textiles, Government of India.

Influence of bonded joint configuration on the cryogenic strength of double-lap composite-metal adhesively bonded joints

The influence of bonded joint configuration on the strength of double-lap carbon fiber reinforced plastic (CFRP)-aluminum alloy bonded joints at cryogenic temperatures was investigated. The bonded joint configurations were double-lap bonded joints composed of CFRP inner and aluminum alloy outer adherends and aluminum alloy inner and CFRP outer adherends. Finite element method (FEM) analysis considering the temperature effect was conducted to evaluate the stress distribution in the adhesive layers of the bonded joints. The calculated peel and shear stresses near the edges of the adhesive layers with the metal inner adherends were lower than those with the composite inner adherends at cryogenic temperatures. The strength of the two types of bonded joints was obtained by tensile tests at room temperature, −50°C, and −150°C. The strength of the bonded joints with the metal inner adherends was higher than that with CFRP inner adherends at cryogenic temperatures because the thermal shrinkage of the metal inner adherends suppressed the stress at the adhesive layer edges.

Monitoring the inverted exponentiated half logistic quantiles under the adaptive progressive type II hybrid censoring scheme

Numerous studies have solved the problem of monitoring statistical processes with complete samples. However, censored or incomplete samples are commonly encountered due to constraints such as time and cost. Adaptive progressive Type II hybrid censoring is a novel method with the advantages of saving time and improving efficiency. On the basis of this scheme, the problem of monitoring a downward shift in the quantiles of the inverted exponentiated half logistic distribution is considered. The conventional Shewhart control chart is insensitive to detect quantile shifts from faulty data processes that exhibit deviations from normality or symmetry. To overcome this limitation, Bootstrap control charts combining with the exponentially weighted moving average method based on the Bayesian estimation and maximum likelihood estimation are proposed, respectively. They are compared with the conventional Shewhart control chart via average run length through Monte-Carlo simulations. Finally, a real dataset related to the tensile strength of carbon fibers is employed to demonstrate the ascendancy of the Bootstrap control charts.

Determination of tensile residual strength of fibre reinforced concrete by a robust and simple test

Determination of tensile residual strength of fibre reinforced concrete by a robust and simple test

Classification and properties of Bambusa blumeana fiber

This study extracted Bambusa blumeana fiber using alkaline boiling and then applied double-roll pressing in order to develop it, explore the applications of its various parts, and improve its utilization potential. The results showed that the outer bamboo fibers are finer and straighter than the inner and middle fibers, and the fracture mode of the bamboo fibers is brittle. From the inside to the outside, the tensile strength of the fiber bundle gradually increases from the top to the bottom. Moreover, the tensile strength of the outside bamboo fiber is twice that of the inside, reaching a maximum of 982 MPa. The surface of the interior bamboo fiber is relatively smooth and can be used in textile and decorative fields. Compared with internal and central bamboo fiber, the outer fiber has higher thermal stability and higher crystallinity, which makes it more advantageous in the process of strengthening composite materials. Studying the structures of fibers from different parts of Bambusa blumeana can provide substantial scientific support for the differential applications of bamboo fibers.

Reliability Estimation in Stress Strength for Generalized Rayleigh Distribution Using a Lower Record Ranked Set Sampling Scheme

This paper explores the likelihood and Bayesian estimation of the stress–strength reliability parameter (R) based on a lower record ranked set sampling scheme from the generalized Rayleigh distribution. Maximum likelihood and Bayesian estimators as well as confidence intervals of R are derived and their properties are studied. Furthermore, two parametric bootstrap confidence intervals are introduced in the paper. A comparative simulation study is conducted to assess the effectiveness of these four confidence interval methodologies in estimating R. The application of the methods is demonstrated using real data on fiber strength to showcase their practicability and relevance in the industry.

Investigation of salt tolerance in cotton germplasm by analyzing agro-physiological traits and ERF genes expression

The development of genotypes that can tolerate high levels of salt is crucial for the efficient use of salt-affected land and for enhancing crop productivity worldwide. Therefore, incorporating salinity tolerance is a critical trait that crops must possess. Salt resistance is a complex character, controlled by multiple genes both physiologically and genetically. To examine the genetic foundation of salt tolerance, we assessed 16 F1 hybrids and their eight parental lines under normal and salt stress (15 dS/m) conditions. Under salt stress conditions significant reduction was observed for plant height (PH), bolls/plant (NBP), boll weight (BW), seed cotton yield (SCY), lint% (LP), fiber length (FL), fiber strength (FS), potassium to sodium ratio (K+/Na+), potassium contents (K+), total soluble proteins (TSP), carotenoids (Car) and chlorophyll contents. Furthermore, the mean values for hydrogen peroxide (H2O2), sodium contents (Na+), catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and fiber fineness (FF) were increased under salt stress. Moderate to high heritability and genetic advancement was observed for NBP, BW, LP, SCY, K+/Na+, SOD, CAT, POD, Car, TSP, FL, and FS. Mean performance and multivariate analysis of 24 cotton genotypes based on various agro-physiological and biochemical parameters suggested that the genotypes FBS-Falcon, Barani-333, JSQ-White Hold, Ghauri, along with crosses FBS-FALCON × JSQ-White Hold, FBG-222 × FBG-333, FBG-222 × Barani-222, and Barani-333 × FBG-333 achieved the maximum values for K+/Na+, K+, TSP, POD, Chlb, CAT, Car, LP, FS, FL, PH, NBP, BW, and SCY under salt stress and declared as salt resistant genotypes. The above-mentioned genotypes also showed relatively higher expression levels of Ghi-ERF-2D.6 and Ghi-ERF-7A.6 at 15 dS/m and proved the role of these ERF genes in salt tolerance in cotton. These findings suggest that these genotypes have the potential for the development of salt-tolerant cotton varieties with desirable fiber quality traits.

Retting with efficient microbial consortium helps in improving jute fibre quality and profitability: a study in Eastern India

Aim: To determine the effect of application of microbial consortium for faster retting of jute (Corchorus spp.) over conventional retting without microbial consortium on jute fibre recovery and fibre quality improvement. Methodology: Large scale retting trials of jute were conducted in five important jute growing districts of West Bengal, India for four consecutive years with and without microbial consortium. After completion of jute retting, fibre was extracted manually, processed and dry fibre weight was recorded. Jute fibre samples were collected and analysed for fibre quality parameters. The fibre strength was estimated using electronic fibre bundle strength tester, fibre fineness by air flow method and root content is measured as the length of fibre up to which root is present out of the total length of the fibre and is expressed as percent length. Results: Application of microbial consortium reduced the retting duration and root content in jute fibre in all the locations irrespective of years. The jute fibre recovery increased by 9.64 to 10.97% and 9.73 to 10.63% with microbial consortium over without microbial consortium respectively in different locations and different years under study. The maximum jute fibre yield with (33.17 q ha-1) and without microbial consortium (29.89 q ha-1) was recorded in Murshidabad district. Nadia district recorded significantly higher fibre strength of 24.92 g tex-1 and lowest retting duration of 11.92 days with microbial consortium among all the locations. Interpretation: The application of microbial consortium improved the fibre recovery and fibre quality leading to the increase in net income by ₹15624 to ₹18017 ha-1 of jute farmers. Hence, the application of microbial consortium for jute retting can be used extensively by the jute farming community in jute growing states of India for faster retting of jute along with quality fibre production, higher net income and doubling farmers’ income. Key words: Corchorus spp., Fibre quality, Jute retting, Microbial consortiu

The Role of Silica Fume in Enhancing the Strength and Transport Properties of PET Fiber–Ultra High-Performance Concrete

The Role of Silica Fume in Enhancing the Strength and Transport Properties of PET Fiber–Ultra High-Performance Concrete

Comparison of the physico-chemical behavior of two prepregs used for body armor

The development of ultra-high molecular weight polyethylene fibers has resulted in continued improvement in ballistic protection, along with reduced weight in body armors. Prepregs from newly developed fibers are constantly available, although prepregs from older brands still remain on the market. In this work, the physicochemical properties of two successive generations of pre-impregnated materials are characterized to compare the two materials in the as-received condition and also after be consolidated in a ballistic plate. The results showed that fibers from the newer brand have a smaller diameter and greater tensile strength. This is an important result because the tensile strength of fibers is one of the variables that influence the ballistic performance of body armors. The smaller diameter of these fibers was associated with a greater degree of stretching during their manufacture, as revealed by the presence of two melting peaks in the DSC analysis.

Aging behaviour assessment of cellulosic fibres in alkaline media: A green technology approach in construction materials

With the increasing demand for buildings, the utilisation of green materials represents a novel approach toward achieving sustainable development goals. Cellulose-based materials, such as jute, exemplify eco-friendly substances for civil engineering applications. The present study aims at studying the aging behavior of jute fibers in an alkaline environment. For this purpose, three alkali environments (NaOH, KOH, Ca(OH)2) with three different concentrations were selected. Samples were treated at three different periods (7 d, 14 d, and 28 d) to assess the impact of treatment on the fiber properties. This study introduces a pioneering concept of the alkali treatment of jute-based fibres to evaluate tensile strength and weight loss, marking the first of its kind. This approach incorporates various characterisation techniques, including Differential Scanning Calorimetry (DSC), Thermo-Gravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) to assess the treatment process. In our experimental procedures, we evaluated key parameters such as the type of alkali, alkali concentration, and curing time for their influence on tensile strength. Subsequently, we applied Response Surface Methodology (RSM) in conjunction with bagging techniques to develop mathematical models based on the acquired data. Results demonstrated varied tensile strengths based on alkali type, concentration, and treatment duration. Fibres treated with 15 g/L concentration of NaOH exhibited an increase in tensile strength from 7 days (79.66 MPa) to 28 days (225.05 MPa). The highest tensile strength of jute fibres treated with KOH was observed with 15 g/L concentration at 14 days (237.58 MPa). For Ca(OH)₂ treatments, the highest tensile strength was observed with 30 g/L concentration at 14 days (111.28 MPa). It was also observed that prolonged exposure to very high alkali concentrations could adversely affect the tensile strength, as observed in the case of 30 g/L concentration of NaOH at 28 days (84.73 MPa). Among the various alkali materials tested, NaOH and KOH demonstrated greater effectiveness compared to Ca(OH)2. According to RSM analysis, the time of sample curing was found to be the most significant factor in tensile strength, with a P-value of 0.009. On average, the tensile strength changes by 54 %, 52 %, and 35 % for NaOH, KOH, and Ca(OH)₂, respectively, when the curing time shifts from 7 days to 28 days.

Influence of electrophoretic deposition of micro- or nanosized silica particles on the microstructure of carbon fibers and their bond behavior with cementitious matrices

The application of carbon fiber (CF) reinforced cementitious composites is often restricted by the poor load transfer between the components. In this study, two reactive coating materials—nano-silica and micro-silica—are utilized to modify the CF surfaces via an electrophoretic deposition approach. These negatively charged particles are able to be electrosorbed onto the fiber surfaces under a constant electrical field according to the zeta and cyclic voltammetry measurements. After surface treatment, XRD analysis of CFs showed an increase in graphite crystallite thickness and decrement in interlayer spacing d002\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${d}_{002}$$\\end{document}, significantly affecting the fiber diameters. Additionally, the lengths of crystallites were reduced, which can impair the fiber strength and their temperature stability. Single fiber pullout tests exhibited that the interfacial bonding can be clearly enhanced by both reactive coatings. Microscopic observation revealed that C–S–H gel and calcite structures can be formed near the fiber surfaces after immersion in cement pore solution owing to pozzolanic reaction and nucleation effect, tremendously heightening both chemical and mechanical interaction between fiber and cement. Finally, based on a detailed micromechanical analysis, the reinforcing mechanisms between the differently modified fibers and the cementitious matrix were elaborated and discussed.Graphical abstract

Efficacious application of data-driven machine learning models for predicting and optimizing the flexural tensile strength of fiber-reinforced concrete

In the literature, a limited number of studies have utilized the random forest (RF) technique to model the flexural tensile strength (FTS) of steel fiber reinforced concrete (SFRC). This study established modeling of the FTS of SFRC containing mono-fibrous (exclusively crimped and hooked) systems. A comprehensive database of 193 records was used from 18 published studies (including 30 documents sampled by authors). Machine-learning numerical models were developed and evaluated. Partial dependence plots were constructed to visualize the relationship between the model parameters and rank the parameters based on their importance. It has been found that the RF model can be rationally used to predict and optimize the FTS of SFRC, as most of the predicted–tested results were close to the ± 80% accuracy range. The model showed of underestimation nature for SFRC with high FTS values. The Gini index-based importance analysis showed that the fiber’s content and tensile strength had the highest significance among the other variables. A drastic increase in the FTS by an increase in the fibrous dosage was achieved. However, no major SFRC’s tensile strength enhancement for dosages was more than 1.5%, while its optimum diameter was 0.5–0.7 mm. The results also illustrated that the effect of the fiber’s length is quite similar to that of the fiber content. However, no significant increase can be achieved by increasing the fiber’s length from 40 to 60 mm.

The role of constitutive properties on the longitudinal compressive strength of composites

The longitudinal compressive strength of fibre-reinforced composites is often a limiting factor for structural design. This paper uses micromechanical finite-element analyses to examine how the constitutive properties of the matrix, fibres, and interface affect the composite’s strength. For a typical carbon/epoxy composite, the matrix shear strength has a larger effect than the modulus; a linear-elastic perfectly-plastic approximation of the matrix shear curve may overestimate the composite’s strength by over 15%. A pressure-dependent and dilatant matrix plasticity response may strengthen the composite by 30%, considering current uncertainties in friction and dilation angles of epoxy matrices. The finite shear modulus of carbon fibres may weaken the composite by more than 10%. Considering a cohesive interface using traction–separation laws significantly affects the predicted response of the composite, even for interfaces stronger than the matrix. Opportunities for improving the characterisation, modelling and performance of the constituents in terms of matrix plasticity, fibre shear modulus, and interface response are discussed.

The synergy of the matrix modification and fiber geometry to enhance the thermo‐mechanical properties of basalt fiber‐polypropylene composites for automotive applications

AbstractBasalt fiber reinforced polypropylene composites with two initial fiber lengths (3.2 and 6.4 mm) were fabricated using twin‐screw extrusion compounding. In the case of composites with smaller initial fiber length, basalt fibers predominantly served as nucleating agents for polypropylene thereby resulting in an increase in the degree of crystallinity. The addition of polypropylene‐g‐maleic anhydride (PP‐g‐MA) caused the matrix to become amorphous, which was due to the establishment of a fiber–matrix interphase. This behavior was different for the composites with relatively larger initial fiber length especially at higher fiber content. The reduction in fiber length in the composites caused a decrease in crystallinity, as this hindered the ability of the polypropylene matrix to form crystals. Addition of PP‐g‐MA established a fiber–matrix interphase thereby synergistically contributing to the increased matrix amorphousness of the basalt fiber reinforced polypropylene composites with 6.4 mm initial fiber length. Reduced fiber length due to processing also accelerated the thermal degradation of the composites with an initial fiber length of 6.4 mm. However, the reduction in fiber length due to processing resulted in increased fiber orientation, which contributed to the improvement in tensile and flexural properties of the basalt fiber reinforced polypropylene composites with an initial fiber length of 6.4 mm. At 30% fiber content, the tensile strength and modulus of basalt fiber reinforced matrix modified polypropylene composites with 6.4 mm initial fiber length improved by 18% and 13% as compared with the composites with 3.2 mm initial fiber length.

Study on Mechanical Properties of Polymer Composites Filled with Nano Egg-shell Powder

Polymeric materials, when reinforced with synthetic fibers like glass, carbon, and aramid, offer notable advantages including increased stiffness and strength-to-weight ratio compared to conventional materials such as wood, concrete, and steel. Among these options, glass fiber stands out due to its affordability and widespread availability. Glass fiber reinforced polymer composites exhibit moderate mechanical properties, which can be significantly enhanced by incorporating nano fillers like eggshell powder. This study explores the utilization of nano eggshell powder as well as methods for effectively integrating nano fillers into polymer composites to create value-added products. Four types of composites, varying in weight proportions of nano eggshell powders, were prepared using the hand lay-up technique for mechanical and thermal characterizations. Various mechanical properties including tensile strength, flexural strength, impact behavior, as well as thermal properties via TGA and DMA analysis were investigated. The results indicate that incorporating the optimal amount of nano fillers significantly improves the overall strength of glass fiber reinforced composite materials, leading to cost savings of over 30%. This suggests that nano eggshell fillers hold great potential in composite manufacturing, particularly for substituting high-cost glass fibers in low load-bearing applications.

Stress-Strain State of Steel Fiber-Reinforced Concrete under Compression Taking into Account Unloading from Inelastic Region

The purpose of the study is to examine the physical and mechanical characteristics of steel fiber-reinforced concrete under compression, including: modulus of elasticity, Poisson ratio, values of ultimate strains under compression, values of compressive strength with different percentages of dispersed reinforcement. An experimental investigation program, which included the production of cube samples measuring 100×100×100 mm, as well as a compression test under static loading, taking into account unloading from the region of inelastic deformations, was developed and carried out. Two types of steel fiber were chosen as dispersed reinforcement: hooked end and wave shape. The volume content of steel fiber in the cube samples was 0.5, 1.0, 1.5 and 2.0 %. As a result of the investigation, the strength and deformation characteristics of steel fiber reinforced concrete under compression were obtained. Based on the experimental data, actual strain diagrams of steel fiber reinforced concrete were constructed, taking into account the type of reinforcing fibers and the percentage of reinforcing fiber. Based on the obtained diagrams, a law of deformation of steel fiber reinforced concrete is proposed, which can be described by a polynomial function of the fourth order with constant coefficients that determine the shape of the stress-strain curve. The presented research results can be used in developing a methodology for physically nonlinear analysis of steel fiber reinforced concrete elements with a percentage of dispersed reinforcement from 0.5 to 2.0 %.

Exploring agro-morphological and fiber traits diversity in cotton (G. barbadense L.)

Cotton (Gossypium barbadense L.) is a leading fiber and oilseed crop globally, but genetic diversity among breeding materials is often limited. This study analyzed genetic variability in 14 cotton genotypes from Egypt and other countries, including both cultivated varieties and wild types, using agro-morphological traits and genomic SSR markers. Field experiments were conducted over two seasons to evaluate 12 key traits related to plant growth, yield components, and fiber quality. Molecular diversity analysis utilized 10 SSR primers to generate DNA profiles. The Molecular diversity analysis utilized 10 SSR primers to generate DNA profiles. Data showed wide variation for the morphological traits, with Egyptian genotypes generally exhibiting higher means for vegetative growth and yield parameters. The top-performing genotypes for yield were Giza 96, Giza 94, and Big Black Boll genotypes, while Giza 96, Giza 92, and Giza 70 ranked highest for fiber length, strength, and fineness. In contrast, molecular profiles were highly polymorphic across all genotypes, including 82.5% polymorphic bands out of 212. Polymorphism information content was high for the SSR markers, ranging from 0.76 to 0.86. Genetic similarity coefficients based on the SSR data varied extensively from 0.58 to 0.91, and cluster analysis separated genotypes into two major groups according to geographical origin. The cotton genotypes displayed high diversity in morphology and genetics, indicating sufficient variability in the germplasm. The combined use of physical traits and molecular markers gave a thorough understanding of the genetic diversity and relationships between Egyptian and global cotton varieties. The SSR markers effectively profiled the genotypes and can help select ideal parents for enhancing cotton through hybridization and marker-assisted breeding.

Behavior of Polypropylene Fibre Reinforced Fly Ash Concrete RC Beams in Flexure

This paper presents an experimental investigation on the polypropylene fibre reinforced fly ash concrete RC beams under flexure. The variables of study include the polypropylene fibre content (0.2 % & 0.4%). The polypropylene fibre and 10% of Fly ash as cement replacement are incorporated in all the concrete mix proportions considered in this study. The experimental test results showed that the compressive strength of concrete increases with the increasing percentage of fibre. The flexural strength of polypropylene fibre reinforced fly ash concrete beams increased considerably than the control concrete beams.