Influence Of Fiber Orientation Research Articles

Physical analysis and statistical investigation of tensile and fatigue behaviors of glass fiber-reinforced polyester via novel fibers arrangement

Polymer composite researchers have extensively explored the influences of fiber orientation, volume fraction, type, length, as well as the impacts of matrix type, matrix/reinforcement interface, fibers hybridization, and nanoparticle incorporation on the mechanical behaviors of fiber-reinforced composite materials. The impacts of tailored fiber architectures on the mechanical characteristics of bulk polymeric-based composites, on the other hand, have not been investigated. The purpose of this research is to determine the effect of fiber arrangement on the mechanical characteristics of glass fiber-reinforced polymeric materials (GFRP). Unreinforced (UR) polyester, surface reinforced arranged (SRA) composites and bulk reinforced arranged (BRA) composites were fabricated. Characterizations have been performed using scanning electron microscope rotating bending fatigue machine and a universal testing machine. Results demonstrate that SRA’s lifespan after being exposed to bending fatigue has increased significantly with respect to UR and BRA samples. Average fatigue life for SRA samples is 61 times longer than the life of BRA samples at 56 MPa bending stress. Furthermore, a Weibull distribution function with shape parameter and scale parameter was implemented to analyze the fatigue life dataset statistically. The introduction of SRA novel design has promising results for cost reduction as well as quality improvement.

Fiber Orientation Influence on Mechanical Properties of SiC Particles Filled Epoxy Based Composites Reinforced with Al mesh and Unidirectional Basalt Fibers

Fiber Orientation Influence on Mechanical Properties of SiC Particles Filled Epoxy Based Composites Reinforced with Al mesh and Unidirectional Basalt Fibers

A probabilistic study into the influences of fiber angle orientations on energy absorption performance of carbon fiber-reinforced polymer composite tubes

The influence of fiber orientations on the crashworthiness of carbon fiber-reinforced polymer (CFRP) composite tubes was investigated to fill in the knowledge gap regarding the effects of fiber angle on the energy-absorbing potential of these tubes. This study adopted the Hammersley sequence sampling (HSS) method to generate a quasi-random distribution of the design objectives. Then, LS-DYNA was utilized for numerical quasi-static crushing tests to measure the specific energy absorption (SEA) and the crushing force efficiency (CFE) of a quasi-static CFRP tube at different fiber angles. The Kriging method was implemented to generate a surrogate model. Finally, Pareto results were extracted deterministically and probabilistically using the NSGAII algorithm. Fiber orientation angles are naturally exposed to uncertainties in the manufacturing process; thus, the main contribution of the study is illustrating the effects of fiber angle orientations on the energy-absorbing characteristics of CFRP tubes while incorporating uncertainties into the optimization procedure. Interestingly, the optimum fiber angle orientations revealed the potential advantage of using non-conventional angle-ply layouts by improving the CFE by up to 4% compared with the initial design configuration. The results also demonstrated the capability and superior performance of the optimization procedure in finding the global optima, and the necessity of conducting a probabilistic examination in similar studies.

Effect of aloe vera natural fibre orientation on the mechanical propertiesof epoxy composites

ABSTRACT Natural fibre reinforced polymer composites have found a wide range of applications in the automobile industry, construction industry and toy industry, and so on. In this research work, bidirectional aloe vera fibre mats were used as reinforcement and epoxy as matrix materials. Hand Layup process was applied for fabrication of aloe vera fibre reinforced epoxy matrix composites which contain different fibre orientations such as 45°, 60°, 75°, and 0°/90°. The goal of this research work is to obtain the influence of fibre orientation on mechanical and water absorption properties. The experimental investigations like tensile strength, flexural strength, impact strength, and the water absorption tests were performed. The surface morphology of the tensile failed test specimens were alsoanalysed using afield emission scanning electron microscope (FE-SEM). When compared to other fibre orientation composites, 0°/90° aloe vera fibre orientation has superior mechanical capabilities and 45° fibre orientation obtained minimum mechanical properties, according to the results of the experiment. As compared to 45° fibre orientation, 90° fibre orientation obtained 283.81%, 168.41%, and 202.54% higher tensile, flexural, and impact strength, respectively.

In situ micromechanical analysis of discontinuous fiber-reinforced composite material based on DVC strain and fiber orientation fields

The influence of fiber orientation and its distribution on the global and local mechanical behavior of a short fiber-reinforced thermoplastic (SFT) composite is studied based on an in situ tensile test using synchrotron X-ray tomography. The in situ test data are utilized to compute three-dimensional (3D) strain fields inside the material at various loading steps through an in-house digital volume correlation (DVC) code. The DVC analysis finds that, although the global strain fields seem relatively uniform, the internal strain fields are locally non-uniform because of the complex reinforcement architecture. The local non-uniformity is further investigated at a single fiber level to find a correlation between the orientation of fibers, fiber volume fraction, and strain field. The investigation is performed on micro-scale subvolumes, in which all the fibers are individually segmented from the 3D tomographic data. It is found that the fibers aligned in the direction transverse to loading impede transversal shrinkage, resulting in a locally small compressive strain in that direction. The in situ test has revealed that the average fiber orientation does not change noticeably even after the global strain reaches 18%. This small change implies that initially-determined fiber orientation is crucial to the locally anisotropic mechanical behavior of a SFT-like material even undergoing large deformation. On the other hand, the loading-directional strain is more affected by the local volume fraction than the fiber orientation. The local volume fraction also mainly determines the stiffness of the subvolume that can be estimated from an analytical homogenization model. The effect of the local volume fraction on the subvolume stiffness is identified from multivariate analysis.

Modal Analysis of Delaminated Flax Fibre Reinforced Epoxy Composite Plate

This paper describes the influence of fibre orientation, delamination size and location on the natural frequencies of the single mid-plane delaminated unidirectional flax fibre reinforced epoxy (FFRE) composite plates under different boundary conditions numerically by using ANSYS MAPDL. The delaminated composite plate was modelled as two separate volumes divided at the midplane of the plate, with the nodes on the intact surfaces merged. In contrast, the nodes on the delaminated region remained separate. The results show that the CCCC delaminated composite plate has the highest fundamental natural frequency (219.996 Hz). Furthermore, for increasing fibre orientation from 0° to 45°, the fundamental natural frequencies decreased by 10.12% for the CCCC condition and increased by 6.01% for the SSSS condition. The fundamental natural frequency for the cantilever condition decreased 60.91% when fibre orientation increased to 90°. Moreover, the CCCC condition significantly reduces the fundamental natural frequency (up to 38.95%) with increasing delamination size. For CCCC and SSSS conditions, the centre delamination possesses the highest fundamental natural frequency (219.996 Hz and 116.525 Hz, respectively). The highest fundamental natural frequency for cantilever conditions is 33.081 Hz, with delamination located at the middle of the width and near the free end.

Influence of Environmental Parameters and Fiber Orientation on Dissolution Kinetics of Glass Fibers in Polymer Composites

Glass fibers slowly dissolve and age when exposed to water molecules. This phenomenon also occurs when glass fibers are inside fiber-reinforced composites protected by the matrix. This environmental aging results in the deterioration of the mechanical properties of the composite. In structural applications, GFRPs are continuously exposed to water environments for decades (typically, the design lifetime is around 25 years or even more). During their lifetime, these materials are affected by various temperatures, pH (acidity) levels, mechanical loads, and the synergy of these factors. The rate of the degradation process depends on the nature of the glass, sizing, fiber orientation, and environmental factors such as acidity, temperature, and mechanical stress. In this work, the degradation of typical industrial-grade R-glass fibers inside an epoxy fiber-reinforced composite was studied experimentally and computationally. A Dissolving Cylinder Zero-Order Kinetic (DCZOK) model was applied and could describe the long-term dissolution of glass composites, considering the influence of fiber orientation (hoop vs. transverse), pH (1.7, 4.0, 5.7, 7.0, and 10.0), and temperature (20, 40, 60, and 80 °C). The limitations of the DCZOK model and the effects of sizing protection, the accumulation of degradation products inside the composite, and water availability were investigated. Dissolution was experimentally measured using ICP-MS. As in the case of the fibers, for GFRPs, the temperature showed an Arrhenius-type influence on the kinetics, increasing the rate of dissolution exponentially with increasing temperature. Similar to fibers, GFRPs showed a hyperbolic dependence on pH. The model was able to capture all of these effects, and the limitations were addressed. The significance of the study is the contribution to a better understanding of mass loss and dissolution modeling in GFRPs, which is linked to the deterioration of the mechanical properties of GFRPs. This link should be further investigated experimentally and computationally.

Thermal Aspects in Edge Trimming of Bio-Filled GFRP: Influence of Fiber Orientation and Silica Sand Filler in Heat Generation.

The present work aims to determine the influence of Glass Fiber-Reinforced Polymer (GFRP) laminating configuration in heat generation during the dry edge trimming process. Temperature measurement experiments were conducted on pure epoxy matrix, 15% unidirectional glass fiber reinforced epoxy, and 28% silica sand-filled GFRP specimens through eight type-K thermocouples evenly distributed along the trim plans and connected to a data acquisition system. Infrared thermographic measurements were also conducted to investigate the tool temperature evolution while processing. It was found that perpendicular fiber edge milling induces a sharp increase with peak temperature measurements reaching 119 °C, while machining parallel to fiber leads to a maximum temperature history of 41 °C, which is very close to that obtained from the pure epoxy test. It was also found that the addition of silica sand grains in the GFRP matrix reduces both tool and specimen temperature magnitudes up to 67% for 90° plies and 14% for 0° plies compared to silica sand-free composite initial values. The heat partition was calculated from the measured (electric) and estimated energies for the tool, the workpiece, and chips, respectively. It appears from predictions that the addition of silica sand grains increases the heat conductivity of the GFRP materials (with rates of 20% for 0° fiber orientation and 10% for 90° fiber direction), while it reduces that conducted to the milling tool. Scanning Electron Microscopy (SEM) inspections helped detect the dominating machining defects relative to each GFRP configuration and explained the heat generation and dissipation effects in light of peak temperature measurements.

Investigation on scratching force and material removal mechanism of 3D SiCf/C–SiC composites during single grain scratching

As one of the novel fiber-reinforced ceramic matrix composites, SiCf/C-SiC composites are difficult to machine materials and the material removal mechanism is not completely clear yet. Single grain scratching tests with gradual depth have been carried out to analyze the influence of fiber orientation and woven structure on the material removal mechanism and scratching force in three typical scratched surfaces defined by the fiber orientation. Results indicate that the scratching force waveform is affected by the weaving method, fibers orientation, and porosity distribution of the scratched area, resulting in periodic fluctuations. Diamond indenter causes greater damage to the surface of SiCf/C-SiC composites when scratching along transverse fibers, while leaving narrow but deep grooves on the surface when scratching along perpendicular fibers. The dominant mode of material removal of SiCf/C-SiC composites is brittle fracture, and the damage features mainly include direct fiber breakage, matrix fragmentation, fiber pullout, fiber outcropping.

Directed invasion of cancer cell spheroids inside 3D collagen matrices oriented by microfluidic flow in experiment and simulation

Invasion is strongly influenced by the mechanical properties of the extracellular matrix. Here, we use microfluidics to align fibers of a collagen matrix and study the influence of fiber orientation on invasion from a cancer cell spheroid. The microfluidic setup allows for highly oriented collagen fibers of tangential and radial orientation with respect to the spheroid, which can be described by finite element simulations. In invasion experiments, we observe a strong bias of invasion towards radial as compared to tangential fiber orientation. Simulations of the invasive behavior with a Brownian diffusion model suggest complete blockage of migration perpendicularly to fibers allowing for migration exclusively along fibers. This slows invasion toward areas with tangentially oriented fibers down, but does not prevent it.

Influence of fiber orientation on the microstructures of interfacial transition zones and pull-out behavior of steel fiber in cementitious composites

The reinforcement of steel fibers on cementitious composites is mainly influenced by the bonding between the fiber and matrix. The steel fibers and matrix bonding depend on the interfacial transition zone (ITZ). A major cause of ITZ formation is microbleeding, i.e., the flow of free water around steel fibers at the early stage of bleeding may cause the redistribution of water and cement particles around the fibers, leading to the formation of ITZs. The fiber orientation in the matrix affects the flow of water and further influences the microstructure of the ITZ around the steel fiber and the bonding properties. This study proposes a theoretical model based on fluid mechanics to investigate the influence of fiber orientation on cement-water suspension migration around steel fibers. The microstructure of the ITZ around the steel fiber is then estimated based on the Powers model according to the water-cement ratio distribution. Finally, the interrelationships among the fiber orientation, ITZ porosity and bond strength are established by curve fitting. The results indicate that since free water with small particles flows past the steel fiber by flowing past circular (or elliptical) cylinders, a difference in the ITZ microstructures at the upper and lower surfaces of the steel fiber arises. As the inclined angle of the fiber increases, the upper surface porosity and the average porosity of the ITZ around the steel fiber decrease, leading to an increase in the fiber-matrix bond strength.

Finite element study on the influence of fiber orientation on the high velocity impact behavior of fiber reinforced polymer composites

Finite element study on the influence of fiber orientation on the high velocity impact behavior of fiber reinforced polymer composites

Influence of Fiber Orientation on Deformation of Additive Manufactured Composites

Anisotropy caused by flow-induced fiber orientation of discontinuous fibers within the extrudate in the Extrusion Deposition Additive Manufacturing (EDAM) process gives rise to anisotropic shrinkage in printed parts and thereby, final part deformations. Three fiber orientation states, described by the second-order orientation tensor, were investigated to determine their influence upon final geometry. Two material systems were investigated including a short glass fiber-reinforced polyamide and a short carbon fiber-reinforced polyamide. A curvilinear geometry was modeled and printed virtually in the thermo-mechanical simulation, ADDITIVE3D©. The scale of the printed geometry was in the range of 300–400 mm and contained three semicircular geometry regions connected to linear regions, thereby inducing significant magnification of the spring-in deformation. The predicted deformation of the printed geometry for the three fiber orientation states and two material systems were compared. The deformation predicted for glass fiber-filled polyamide and carbon fiber-filled polyamide of the same fiber orientation states showed comparable deformations. The largest residual deformation was shown to correspond to the orientation tensor with the greatest degree of anisotropy.

繊維配向角を考慮した一方向繊維強化複合材料の素材の材料定数変動に対するマルチスケール確率応力解析

Multiscale stochastic stress analysis of unidirectional fiber reinforced composites considering microscopic randomness has been reported in recent, but most of them consider the fiber direction or transverse direction loading. On the other hand, unidirectional fiber reinforced composites are used at arbitrary orientation angles in forms such as laminated materials, so it is necessary to consider influence of fiber orientation when analyzing the stochastic problem. In this report, the influence of fiber orientation angle on the stochastic properties of microscopic stresses is investigated with using multiscale stochastic stress analysis considering the variation of elastic properties component materials of a unidirectional fiber reinforced composite material for various fiber orientation, and the effectiveness of a perturbation-based approach for this problem is investigated.

Characterization of continuous Hibiscus sabdariffa fibre reinforced epoxy composites

The influence of fibre orientation on physical, mechanical and dynamic mechanical properties of Hibiscus sabdariffa fibre composites has been studied. The composites with longitudinal (0°), transverse (90°) and inclined (45°) fibre orientation were prepared using the hand layup technique. ASTM standards were used for characterization of continuous Hibiscus sabdariffa fibre composites. The composite with longitudinally placed fibres yields improved mechanical characteristics. The addition of longitudinal (0°) oriented continuous Hibiscus sabdariffa fibres to the epoxy enhances tensile strength by 460%, flexural strength by 160% and impact strength by 603% compared to neat epoxy. The longitudinal (0°) fibre oriented composite offers higher resistance to water absorption and thickness swelling compared to other types of composites. All continuous Hibiscus sabdariffa fibre epoxy composites possess an improved storage modulus than the neat epoxy resin. The glass transition temperature of continuous Hibiscus sabdariffa fibre composites is 8%–31% lower than that of neat epoxy. Scanning electron microscopy (SEM) images confirm the existence of voids in the matrix, fibre pullout and crack propagation near the fibre bundle, which indicates the stress transfer between fibre and matrix is non-uniform.

Simplified analytical model to assess key factors influenced by fiber alignment and their effect on tensile performance of UHPC

The increase in single-fiber pullout strength usually improves tensile strength and toughness of UHPC. An increase in fiber orientation angle (θ) up to 45° to the direction of pullout load was found to enhance the single-fiber pullout strength. However, such increase in predominant θ value along tensile strength specimens led to a reduction in tensile strength of UHPC. In order to elucidate this controversial observation, analytical models combined with experiments were carried out to assess the key factors influencing the tensile properties of UHPC due to variations of fiber orientation. The test parameters involved the evaluation of the effect of θ (0°–60°) and fiber embedment length (le) of 5 and 10 mm on the single-fiber pullout performance. The influence of fiber orientation on UHPC tensile performance was also investigated by casting tensile strength samples having predominant θ values of 25°, 30°, 40°, and 50° along the tensile loading direction. Test results indicate that the key factors influencing the tensile properties of UHPC included the fiber-matrix bond strength (τθ), le, and fiber number in a given cross section (Nf). The highest τθ was obtained at a θ value of 45°. The increase in θ from 0° to 90° led to a consistent reduction in le and Nf. A simplified model that considers these factors was proposed to assess the effect of each factor on UHPC tensile strength. The model indicates that le had the greatest influence on tensile strength, followed by Nf and τθ. The decrease of predominant θ in tensile strength specimen from 45° to 25° enhanced le by 65% and Nf by 60%, compared to a 7% reduction in τθ, thus leading to a net increase in tensile strength of UHPC by 60%.

Effect of Fibre Orientation on Impact Damage Resistance of S2/FM94 Glass Fibre Composites for Aerospace Applications: An Experimental Evaluation and Numerical Validation.

This study aims to investigate the influence of fibre orientation and varied incident energy levels on the impact-induced damage of S2/FM94, a kind of aerospace glass fibre epoxy/composite regularly used in aircraft components and often subjected to low-velocity impact loadings. Effects of varying parameters on the impact resistance behaviour and damage modes are evaluated experimentally and numerically. Laminates fabricated with four different fibre orientations , , and were impacted using three energy levels. Experimental results showed that plates with unidirectional fibre orientation failed due to shear stresses, while no penetration occurred for the and plates due to the energy transfer back to the plate at the point of maximum displacement. The impact energy and resulting damage were modelled using Abaqus/Explicit. The Finite Element (FE) results could accurately predict the maximum impact load on the plates with an accuracy of 0.52% to 13%. The FE model was also able to predict the onset of damage initiation, evolution, and the subsequent reduction of the strength of the impacted laminates. The results obtained on the relationship of fibre geometry and varying incident impact energy on the impact damage modes can provide design guidance of S2/FM94 glass composites for aerospace applications where impact toughness is critical.

Influence of fiber orientation and structural-integrity reinforcement on the flexural behavior of elevated slabs

In the last decades, research works regarding the behavior of Fiber-Reinforced Concrete (FRC) showed that the use of fibers enhances the mechanical behavior of Reinforced Concrete (RC) structures both at Serviceability Limit State (SLS) and Ultimate Limit State (ULS). It is also well recognized that the design of these elements should take into consideration fiber orientation since the residual properties of the material can be different depending on the fiber inclination with respect to the cracking plane. This article presents the results of an experimental program aimed at evaluating the influence of fiber orientation on the flexural response of elevated slabs. Both Vibrated Fiber-Reinforced Concrete (VFRC) and Self-Compacting Fiber-Reinforced Concrete (SCFRC) were analyzed. Seven elevated slabs (250 × 250 × 15 cm) were cast following the most common casting process adopted in practice by using VFRC (2 specimens), SCFRC (4 specimens) and plain concrete (1 specimen). The post-cracking mechanical properties evaluated by three-point bending tests on 192 notched beams sawn from three FRC slabs showed that, for a given fiber type and amount, the fiber orientation in slabs was comparable varying both concrete workability and casting procedure. The structural behavior of the remaining four slabs was studied both by experimental tests and numerical analyses. The slabs were simply supported at the corners and subjected to center-point loading. Results showed that the response in flexure was related to the average residual properties obtained from small beams sawn from slabs. Finally, the importance of having a structural-integrity reinforcement in FRC elevated slabs under flexure was also underlined by the numerical study.

An experimental-analytical scale-linking study on the crack-bridging mechanisms in different types of SHCC in dependence on fiber orientation

A scale-linking, experimental study complemented by an analytical model was carried out to investigate the influence of fiber orientation on the crack-opening behavior of strain-hardening cement-based composites (SHCC). Three SHCC compositions were investigated with polyvinyl alcohol (PVA) and ultra-high molecular weight polyethylene (UHMWPE) fibers in combination with normal- and high-strength matrices. The micromechanical experiments with fiber inclinations of 0°, 30°, 45°, and 60° involved fiber embedment in plain and fiber-reinforced specimens. The experimentally derived micromechanical parameters were input into an analytical crack-bridging model to assess the upscaling accuracy of the micromechanical results by comparing the predicted crack-bridging laws to the single-crack opening behavior of equivalent miniature SHCC specimens with controlled fiber orientation. This study yields new insights into the effect of fiber orientation on the crack-bridging properties of different types of SHCC, assesses the link between micromechanical and composite scale properties, offers a solid experimental basis for refining the analytical models, and developing anisotropic materials models for SHCC in dependence on fiber orientation.

Mechanical Analysis of Ice-Composite and Fibber Strength by Daily Tools

The analysis on mechanical properties of ice-composite focus on three aspects. The first is the novelty of the material. As an ice composite, the selection and placement of different fibres will have a crucial impact on the material and properties of the composite. Regarding the type of fibre,10 groups of controlled experiments are designed totally with materials commonly used in daily life, with three samples in each group and 33 samples in total. The fillers include cloth of socks, polyester fibre plastic bags (hard, soft, garbage sorting bags), pulp, hemp ropes, nylon ropes, non-woven fabrics, bamboo fibre, and the mask material applied in preventing COVID-19 specially. Considering that in most cases, the mask is a one-off, it is also creatively thought of using disinfected waste masks as reinforcement material for the ice-composite to reduce the waste of recyclable materials. Considering that disposable masks commonly used in this scheme usually consist of an inner and outer layer, as shown in the figure. The applicability of these two fibres was investigated by adding these materials prepared by the inner and outer layers of masks into the Ice-composite. In order to systematically study the influence of different variables on ice composites, different control groups in four directions are set: fibre type, fibre content, fibre length, and fibre orientation. For each control group, more than 2 types of materials were tested and relevant parameters were analysed according to the results. In addition, as a result of the experiment environment to room temperature, and in the process of operation, hands and other body parts contact could accelerate the melting of the ice, leading to the change of the sample properties. To conquer this problem, a blank control group which contains only ice at room temperature is set to make a comparison and provide a standard for determining the improvement of fibre added ice-composite. (The parameters measured in this sample will be used as correction factors in the experiment so that the real properties of the resulting ice composite can be measured.) Considering the influence of fibre orientation on material properties, an extra control group for the same kind of materials is set: one group is stirred evenly with the matrix, and the other group is placed vertically along the direction of the box. In terms of testing, the mechanical properties of the products are mainly tested, including Stiffness Properties, Elastic property. Three related physical properties, the elastic modulus E, the shear modulus G, and the Poisson’s ratio V, are measured to evaluate. Tensile and compressive strength in X, Y, and Z directions are also considered. In particular, different evaluation systems are established for uniform and multilayer unidirectional composite (longitudinal). In addition, a series of properties, such as bend strength, impact strength, and fracture toughness are measured. Considering the limits of daily measuring instruments, the melting of ice in the operation process affects the measurement of normal strain and the fact that the strain of ice composite material is relatively small, it is creatively thought to use a laser pointer and cosmetic mirror which are common in the multimedia classroom of the university campus to magnify the tiny deformation to facilitate measurement. In terms of the result presentation, it is tried to use broken line charts to show the correlation between various variables and material properties. Finally, the error sources existing in the experiment has been summarized and some improvement plans are proposed according to the existing problems of this experiment.