Fiber Volume Percentage Research Articles

Multi-objective optimization and modeling of a natural fiber hybrid reinforced composite (PxGyEz) for wind turbine blade development using grey relational analysis and regression analysis

Due to the increasing demand for clean and sustainable energy, wind turbine technology has also witnessed significant developments in terms of its output capacity which is proportional to its size (length of wind turbine blades). The only limitation to this scaling is the availability of applicable materials with expected strength and low weight which can support a longer span wind turbine blade. Although studies have been carried out on alternate materials for the development of wind turbine blades, the use of Grey Relational Analysis for the optimization of natural fiber-reinforced composites for this application is rare. Also, pineapple leaf fiber, having considerable mechanical properties and low density has not been optimally considered as reinforcement in this regard. This is a robust study concerned with developing more eco-friendly materials for application in the manufacture of wind turbine blades. In this study, a material PxGyEz, a natural fiber/synthetic fiber polymer composite was developed and optimized based on the major criteria for selecting materials for wind turbine blades which are high tensile strength, high flexural strength, and low density. Grey relational analysis coupled with the Taguchi robust optimization technique was used for the optimization process and statistical analysis was employed to know the percentage contribution of each of the variable parameters (PALF volume percentage, glass fiber volume percentage, and fiber length) to the grey relational grades. The material P10G20E15 was the optimum having a grey relational grade of 0.7977 at experimentation and tensile strength of 95.3144 MPa, a flexural strength of 92.818 MPa, and a density of 1.3274 g/cm3. SEM analysis showed microstructural formations that explained the mechanical and physical behavior of the optimized hybrid composite. Simulation of an NREL 5 MW wind turbine blade developed with the optimized material P10G20E15 proved reliable for service with a 64% reduction in weight.

Application of Carbon Fiber Cement-Based Composites in Improving Construction Durability.

In order to improve the durability of building construction, this study proposes a construction method based on carbon fiber and cement-based composites. Analyze the mechanical properties of carbon fiber cement-based composites, combined with experiments to further analyze its advantages in building construction, to achieve the purpose of building durability construction. The experimental results show that the elastic modulus of CFRC samples with a 0.6% carbon fiber volume percentage is the largest. When the content of carbon fiber increases within a certain range, the elastic modulus of CFRC samples will also increase. Conclusion. The application of carbon fiber cement-based composites in building construction can effectively improve the durability of buildings and further improve the quality of buildings.

Analysis and optimisation of the rheology–strength relationship of basalt-fibre-reinforced self-compacting mortar

The aim of this work was to find the optimum rheology for maximising the strength of basalt-fibre-reinforced self-compacting mortar (BFRSCM). An experiment was employed to design mixes based on the basalt fibre volume percentage (F), water/binder ratio (w/b) and superplasticiser (SP) dosage. Using an L9 Taguchi array, nine mixes were designed considering combinations of F (0.5, 1.0 and 1.5%), w/b (0.35, 0.40 and 0.45) and SP dosage (DSP) (16, 19 and 22 ml/kg). Mini slump flow diameter (SFD) and mini V-funnel time (Tv) were measured to determine the rheological characteristics and compressive strength (CS) and split tensile strength (STS) were conducted to determine the mechanical properties of the BFRSCM mixes. After statistical analyses, optimisation and prediction, rheology–strength relationships and optimum properties were ascertained. For further assessment of microstructures, scanning electron microscopy was conducted on three different mixes. It was found that the optimum combinations of (F, w/b, DSP) for CS and STS were (1.0%, 0.35, 19 ml/kg) and (1.5%, 0.40, 16 ml/kg), respectively. The optimum fibre percentage for CS was F = 1.0%, while for STS it was F = 1.5%. The optimum rheology for maximum CS occurred with SFD = 27.5 cm and Tv = 7.9 s, while that for maximum STS was with SFD = 29 cm and Tv = 5.0 s. The mean absolute percentage errors of the predictions for all properties were lower than 5% except for Tv, which was 13%.

Experimental investigation of mechanical and dynamic mechanical properties of sansevieria roxburghiana /epoxy composite using Taguchi design

The focus of this research was to study how process parameters including fibre alignment, fibre length, fibre volume percentage and alkali pretreatment affected the mechanical and dynamic mechanical characteristics (DMA) of the sansevieria fibre composite. The nonwoven fabric was produced through the needle punching technique. 18 composite samples have been produced according to L18 Taguchi design. Four different process parameters were considered for investigation, such as fibre length, fibre volume fraction, the concentration of alkali and fibre alignment. Using Design S/ N ratio analysis, the optimized process parameters for achieving maximum tensile, flexural and compression properties of the composite were measured. In the case of DMA analysis, three different parameters have been calculated only for selected samples such as storage modulus, loss modulus and loss factor. Variance analyses were carried out to measure the statistical influence of the process parameters on response. After this, validation of experiments was also done. SEM study was also carried out to understand the damage pattern of the composite sample.

Impact behavior of long glass fibre reinforced aluminum metal matrix composite prepared by friction stir processing technique for automotive

This work dealt with the fabrication of novel long glass fibre reinforced aluminum metal matrix composite (LGFRAMMC) material for automotive applications. The composite specimens were prepared by incorporating long glass fibre with different fibre volume percentage (50, 66, 80, and 100 vol.%) as reinforcement in aluminium alloy (Al6061) using the friction stir processing (FSP) method. The mechanical behaviour of the composite materials was investigated for their primary loading conditions such as tensile and Izod impact stress. Microstructural characterization and fractured mechanism of the fabricated composites were carried out by scanning electron microscope (SEM) analysis. The tensile strength and elongation of the developed composite specimens decreased with the incorporation of long glass fibre, whereas the Izod impact strength of the developed composite specimens was significantly improved as compared to the conventional base metal (Al6061) body panels used in automobiles. The low tensile strength of LGFRAMMC specimens compared to base metal was because of tunnel defect, brittle fracture and extreme plastic deformation (EPD) as characterized by fibre pull-out, pits, and micro cracks. The synergetic effects of EPD and reinforcing by long glass fibres lead to a remarkable improvement in the impact strength.

Experimental and numerical analysis of the behavior of corroded steel plates strengthened with thin-ply glass/carbon hybrid FRP composites

An experimental and numerical study on the behavior of strengthening corroded steel plates using stepped ends of thin-ply hybrid FRP composites is carried out. The results showed that the hybrid strengthening of corroded steel plates mainly affected the elastic behavior. Debonding of FRP laminate was also witnessed after steel yield. Increasing the number of carbon layers increased the stiffness of the strengthened corroded plate. An enhancement in yielding load was achieved as the volume percentage of lower strain fiber in hybrid combinations decreases. The higher the tensile strength to the layer thickness ratio the higher the load of the strengthened specimen. The strengthening scheme using combination of one glass layer followed by one layer of medium elastic carbon increases the yield limit by 13% for 67% reduction in thickness where the same strengthening increases the yield limit by 7% for 22% reduction in thickness.

A study of parameters affecting mechanical characteristics of hybrid composite

Synthetic and natural fibre reinforced composite attracts various sectors from aviation to spacecraft because of high stiffness, strength & lightweight, and due to these features, composite replacing the metal. During usage of composite, it goes under various loading conditions, i.e., static and dynamic. Tensile and fatigue tests are always recommended for these loading conditions. Both composites and metals are behaving alike as compared to each other during different loading conditions. The damage of composite in fatigue can be seen in three stages, i.e., crack initiation, crack propagation, and fibre failure, which is responsible for bearing a load. In this paper, a variety of parameters including fibre volume percentage, frequency, stress ratio, and fibre orientation have been considered. Generally, 45–60% of the fibre is considered the most significant outcome rather than a higher volume fraction in the context of fatigue and tensile. In the situation of unidirectional fibres, the greater the number of fibres oriented with the loading direction, the higher the fatigue and tensile strength. The fatigue life of angle ply is found to be better with the frequency of 5–10 Hz while, for cross-ply, it is 10–20 Hz. This paper gives brief ideas of various factors which are affecting the stiffness and strength of the composite and are helpful in the betterment of mechanical characteristics.

Mechanical and Rheological Properties of Glass Fiber-Reinforced Flowable Mortar (GFRFM): Optimization Using Taguchi Method

In this study, an attempt was made to link the strength to the rheological properties of glass fiber-reinforced flowable mortar (GFRFM), and optimize the strength using the Taguchi method. With this regard, first the main factors influencing the rheology, including superplasticizer (SP) ratio, water-binder ratio (w/b), and fiber volume percentage (Vol.%) were identified. Then, by setting three levels for each factor and using L9 Taguchi array, 9 groups of experiments were designed and conducted on GFRFM mixes. The rheology of each mix was measured using the mini slump and mini V-funnel tests, and the strength was measured using compression and split tensile tests. Afterwards, the analysis of variance (ANOVA), optimization, and prediction of the mechanical and rheological properties were performed. Finally, the optimum levels of the factors for the maximum strength were found as SP = 16 mL/kg of binder, fiber Vol.% = 0.5, and w/b = 0.35, and the corresponding rheological properties were determined. It was found that the optimum rheology occurs between the minimum and maximum values. Microstructural assessment of the mixes conducted using scanning electron microscope (SEM) also indicated a denser microstructure of the optimum mix.

Utility-Taguchi based hybrid optimization approach in machining of graphite composites

In the present scenario, composites material is widely used in various engineering areas like satellite components, aircraft parts, chemical and sports industries. Graphite is an allotrope of carbon that possesses various electrical and mechanical properties. In this paper, graphite is taken as reinforcement into the epoxy matrix. In this study, the hybrid optimization module is developed to tackle multi-objective machining performance optimization issues. Utility concept coupled Taguchi approach is used to find out optimum values of responses in three input factors i.e., drill speed, feed rate and fiber volume percentage varied at four discrete levels and surface roughness (Ra) and material removal rate (MRR) are taken as process response. Taguchi L16 OA has been used to perform the machining operation. Multiple responses aggregated into a single function i.e., overall utility (U) and finally optimized by the Taguchi concept. Utility embedded Taguchi approach determined the favorable machining setting which the confirmatory test has verified shows satisfactory results. ANOVA outcomes reveal that feed rate (73.37%) is the most important factor trailed by drill speed (3.44%) and fiber volume percentage.

Cracking behavior and energy consumption of Steel Fiber Concrete Encased Steel beams

Steel Fiber Concrete Encased Steel (SFCES) beams were subjected to bending to investigate the effect of steel fibers on the behavior of Steel Reinforced Concrete beams with or without steel reinforcement. 18 SFCES beams reinforced with steel fibers, steel reinforcement, or both were cast. The parameters considered in the experiment were (a) the volume percentage of steel fiber (0%, 1%, and 2%), (b) the shear span to depth ratio( s/d = 2.5 and 3.5), (c) the stirrups spacing (180 mm and 360 mm), and (d) the presence or absence of longitudinal reinforcement (2Φ8+2Φ10).The cracking load, crack development, energy dissipation capacity, and ductility of the specimens were investigated. The results illustrate that the cracking load F c, the total energy consumption, and the energy ductility increase with increasing steel fiber volume, and the average improvement with a steel fiber volume increase of 1% can reach 36.5%, 21.2%, and 28.67%, respectively. However, this strengthening effect of steel fibers was weakened due to the addition of steel reinforcement. The influence of the steel fiber volume and reinforcement configuration on each stage of energy consumption was mainly concentrated in the elastic ( E 1) and failure stages ( E 3). Finally, mathematical equations were proposed to predict the cracking load and crack width of the SFCES specimens, which were verified by comparing the predictions with the experiment results.

Tensile and flexural characteristics of an epoxy-glass composite reinforced with Cloisite 15A nanoclay

Nanoclay weight percent, glass fiber volume percent and angle of orientation of fibers were selected as parameters to study their effect on tensile and flexural characteristics of epoxy-glass-clay nanocomposites (EGCNs). Response surface method (RSM) was utilized to analyze and fit a regression model for the tensile and flexural strength. The optimum values of ultimate tensile strength (UTS) and flexural strength (σf) were 273.47 and 210.14 MPa, respectively, which were predicted using regression models at 2.5% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. The predicted results were confirmed by performing experiments at the optimum conditions which were obtained as 262.37 and 214.76 MPa. The optimized result showed that UTS and σf were improved up to 30.8% and 36.3% compared to the composite containing 0% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. The optimum values of tensile and flexural modulus were obtained as 25.99 and 11.81 GPa, respectively, which were 12.2% and 10.7% higher compared to those values of EGCN containing 0% (by wt) of nanoclay, 31.5% (by vol) of glass fiber and 0°/90° of fibers orientation. XRD test conducted to check the intercalation/exfoliation of the clay in the composite. The fracture surfaces of the EGCNs investigated by scanning electron microscopy (SEM) revealed that the failure occurred by crack propagation in the matrix followed by fiber breakage with little fiber-matrix debonding, whereas in case of EGCN with 0% (by wt) C15A fiber-matrix debonding followed by fiber breakage was observed.

Mix Design Analysis on the Steel Fiber Reinforced High Strength Concrete

As a relatively new construction material, steel fiber reinforced concrete gradually plays an important role in building construction, frame joints, roof waterproofing, underground waterproofing and other engineering fields. At the same time, the mixing design of fiber reinforced concrete is also becoming more important. This paper analyzed two experiments held to explore the influences of different factors on the strength and economic efficiency of steel fiber reinforced concrete. The first one was Research on Direct Design Method of Steel Fiber High-strength Concrete Mix conducted by a research group from North China Institute of Water Resources and Hydropower; the other one was Mix Design and Performance Calculation Method of Steel Fiber Recycled Concrete conducted by Lijuan Zhang from Zhengzhou University. The mutual results were explored and the two methods were compared and analyzed. Through the data and analysis, it was found that the strength of concrete would increase as the increasing of volume percentage of steel fibers and the decreasing of water-cement ratio. The effect of enhancement by steel fibers on compressive strength was relatively small. Besides, the cost of steel fiber concrete was higher than traditional concrete. Using recycled aggregates to mix concrete could make steel fiber reinforced concrete more economically and environmentally friendly.

Investigation on effects of fiber loading of mechanical properties of banana/sisal hybrid composite

Natural fiber reinforced composites (NFRPCs) are picking up favour over man-made fiber inferable from their lower cost and ecological amicable attributes, as they exist plentifully and are sustainable. The ever-evolving ecological, biological, and prudent concerns lead to expanded acknowledgment of natural fiber in each territory of conventional synthetic material application. This is due to great fatigue as well as corrosion resistance, comparable strength, low cost, low density, abundantly available, nontoxicity and biodegradability and etc. of natural fibers. In the present study, the optimization of most commonly used natural fiber reinforced composites that is Banana and Sisal fiber hybrid composite on the basis of fiber loading and fractional distribution of banana and sisal fiber has been discussed. For Finite Element Analysis, the CAD model of specimens with different fiber loading ranging from 20 to 50 percent as well as with different fractional distribution of banana and sisal fiber were prepared as per the ASTM standards using CREO 5.0 modelling software. The specimens were loaded in order to get the failure in the specimen with the help of CAE software named as ANSYS 16.0. The trend in values of load are in very close resemblance to that obtained by Idicula et al. which provides experimental validation to the results of this finite element study. It was concluded that with increase in total fiber volume percentage the flexural and the tensile strength of the composite also increases. Since, the strength of banana fiber is significantly higher than that of sisal fiber that hence higher degrees of strength were observed with increase in concentration of banana fiber.

Study on the effects of fiber orientation on the mechanical properties of natural fiber reinforced epoxy composite by finite element method

Natural Fibers being environment friendly and sustainable materials are gaining the interest of scientists, researchers and industrialists all over the world. Natural Fibers composite being lighter and cheaper than the synthetic fiber composites are seen as a scope for advancement in the ever evolving field of material science. Moreover, natural fibers unlike synthetic fibers are biodegradable in nature which draws the eyes of environmentalists towards them in these high times. In the present study, the optimization of most commonly discussed natural fiber reinforced composites such as Banana fiber, Jute fiber, Kenaf fiber, Hemp fiber and Pineapple Leaf fiber (PALF) on the basis of fiber orientation has been discussed. Finite element models of each fiber reinforced epoxy composite was prepared at constant fiber volume percent of 30% with fiber orientation angles of 0°, +22.5°/−22.5°, 45°/−45°, +67.5°/−67.5° and 90° measured from horizontal axis. The models were loaded for different standard loading conditions, i.e., tensile, flexural, and hardness test. From the results it was observed that for tensile and flexural test all the fibers showed minimum stress at the orientation of 0° and 90°. In Brinell harness test, composites with 45o angle of orientation shows the best results.

Evaluation of surface finish technology in the manufacture of Oxide-Oxide ceramic matrix composites

Oxide-Oxide ceramic matrix composites (Ox-Ox CMCs) enable improved performance properties relative to titanium, inconel and other high-temperature alloys, as high-temperature components in the aerospace and advanced energy sectors due to their low density, oxidation and corrosion resistance, and high heat resistance. However, the high surface porosity and roughness of Ox-Ox CMCs can be problematic in some applications, especially where airflow, drag and friction play a factor in overall performance. The present study explores the application of an Ox-Ox CMC surfacing film designed to co-cure and sinter with composite parts manufactured using Ox-Ox pre-impregnated fabrics with the intention of providing improved surface finish. This surfacing film aims to reduce surface roughness, improve smoothness and airflow, reduce surface porosity and improve resistance to thermal cycling by minimizing microcracking. The film is based on Ox-Ox chemistry compatible with current systems in the market and can withstand temperatures up to 1400 °C. Surface properties and mechanical properties are evaluated and reported on Ox-Ox CMC laminates prepared with and without surfacing film. Results indicate that the Ox-Ox CMC surfacing film provides meaningful improvement in surface quality and in damage tolerance. Marginal reduction in fiber volume percentage was observed due to the increased matrix contribution from the surfacing film.

On the use of differential quadrature-three-term conjugate finite-step length methods for reliability analysis of steel fiber-reinforced sinusoidal rupture beams

The reliability of a complex mathematical problem is presented in this work. The problem is a rupture concrete beam reinforced by steel fibers with various orientation angle. The structure is simulated by sinusoidal shear deformation theory and energy method. Harmonic differential quadrature method is applied for the solution of the problem under the buckling load. The reliability analysis of the mentioned system is studied utilizing a three-term conjugate finite-step length (TCFS) approach. The TCFS is formulated utilizing the conjugate gradient method with a limited scalar parameter to reach the numerical stabilization. The implicit buckling limit state function of the structure includes different parameters of length to thickness ratio of the beam, volume percent and orientation angle of steel fibers, rupture constant and boundary conditions. The results show that the failure probabilities of the studied structure may be decreased by increasing the rupture constant. In addition, the orientation angle of zero is the best choice for steel fiber in the concrete beam.

Study on the effects of fibre volume percentage on banana-reinforced epoxy composite by finite element method

Researchers and engineers have shifted their interest from synthetic fibres to natural fibres. These fibres are not only light weight and high-strength materials but are also more economical than the conventional synthetic fibres. Moreover, the natural fibres are eco-friendly and biodegradable. Banana fibre is a bi-product of banana fruit cultivation and hence abundant in nature. Banana fibre being one of the strongest natural fibres can be used for different applications when reinforced with some binding resin. Epoxy resin has excellent binding properties and is thus suitable matrix for composite formation. As it has been widely discussed in previous studies that fibre loading or fibre volume fraction affects mechanical strengths and properties of natural fibre-reinforced composite, this study is aimed finding the relation between the fibre volume percentage and the load-bearing capacity of banana fibre-reinforced epoxy composite material by data-driven decision method. In the finite element analysis conducted on the banana-epoxy composite, it has been seen that the composite bear maximum tensile load of up to 7956 N, flexural load of up to 411 N and has hardness of up to 167.28. On the basis of this study, it can be said that due to excellent load-bearing properties, banana-epoxy composite can be used for various medium to high-load industrial applications. The following paper also proposes an analytical relation based on the regression model superposition of the results of tensile, flexural and hardness test simulation conducted by finite element analysis software ANSYS 16.0 which was prepared on Minitab 19 software.

Tribological and thermogravimetric analysis of pineapple fibre reinforced epoxy composite

Natural fibre composites are preferred for various static and dynamic applications owing to its biodegradable capacity and strength. Pineapple fibres obtained by the retting process from pineapple leaf were successfully reinforced with epoxy resin with different fibre volume percentage. The wear rate and the thermogravimetric analysis of the polymer composite were studied. It was discovered that 30% reinforcement of pineapple fibre resulted in better wear and higher glass transition temperature due to the optimal fibre volume fraction and enough wetting of the resin on the fibre.

Axial compressive behaviour of steel fibre reinforced self-stressing and self-compacting concrete-filled steel tube columns

This study attempted to explore the effects of initial self-stress in concrete and steel fibre on the compressive behaviour of concrete-filled steel tube (CFST) columns. A total of 36 CFST columns with a radial self-stress ranging between 3.31 MPa and 6.66 MPa and a steel fibre volume percentage of 0, 0.6% and 1.2% were tested under axial compression. The steel tube thickness of 2.5 mm, 3.5 mm and 4.25 mm was used to achieve different confining stiffness to the expansion of concrete core. The concrete strength grade of C40, C50 and C60 was used to obtain different expansion deformations. The failure mode, axial load-axial shortening curve, ultimate load and ductility of CFST columns were investigated. Experimental results showed that all specimens exhibited shear failure, and neither self-stress nor steel fibre had obvious influence on the failure mode. Self-stress in concrete enhanced the ultimate load of the CFST columns by 9.8%–27.6%, but decreased their deformability significantly. Adding steel fibres could enhance the ultimate load and slightly improve the post-peak behaviour and ductility of CFST columns with self-stress. Based on the results of this study and literature, an optimum self-stress level (the ratio of radial self-stress and concrete strength) of 0.10 is proposed. Finally, formulas are proposed to predict the load carrying capacity of FSS-SCCFST columns under axial compression, and the predictions agree well with the test results.

Influence of Barchip fiber on early-age autogenous shrinkage of high-strength concrete internally cured with super absorbent polymers

High-strength concrete (HSC) usually suffers the high early-age autogenous shrinkage owing to the low water-binder (w/b) ratio. Barchip fiber and super absorbent polymers (SAPs) have been utilized to reduce the autogenous shrinkage of HSC at early age. The relationship between autogenous shrinkage and ultrasonic velocity of internally cured high-strength concrete (ICC) reinforced with Barchip fiber was studied utilizing the non-contact shrinkage test. Experimental study and corresponding analysis demonstrated that: (1) the autogenous shrinkage and ultrasonic velocity of concrete decreased with the volume percentage of Barchip fiber increasing, and decreased with the addition of SAPs; (2) models for predicting early-age autogenous shrinkage strain and ultrasonic velocity of ICC reinforced with Barchip fiber considering the fiber volume percentage and age were proposed; (3) the model of early-age autogenous shrinkage strain based on the results of ultrasonic velocity at different ages and at 28 d with no addition of Barchip fiber was proposed; (4) the prediction model of early-age autogenous shrinkage strain of ICC reinforced with Barchip fiber based on the age-dependent parameter on ultrasonic velocity was proposed.