Woven Reinforcement Research Articles

Geometric modeling and finite element analysis of kevlar monolithic and carbon-kevlar hybrid woven fabric unit cell

The prediction of the mechanical strength of composites must be known before use or fabrication. The computerized modeling and analysis helps in prediction of the realistic performance of the composite products. The current research work presents the modeling routs of yarns, yarn interpolation for path, cross-section, and orientations with finite element analysis of woven fabric reinforcements. The geometrical modeling routes of textile woven reinforcements at meso-scale described by using TexGen 3.10, which is a python scripted software package, developed by the polymer composites group at the University of Nottingham, UK, works as a preprocessor for characterization of textile reinforcements. The finite element analysis of textile woven reinforcements is done by using a commercially available software package ABAQUS 6.14-5. Due to the similarity of python scripted codes in both the software’s, ABAQUS is considered as an analysis tool for textile reinforcements among the so many FE based platforms. Textile woven fabric unit cell having plain and twill weaving patterns are explained with Kevlar (monolithic) and Carbon-Kevlar (hybrid) yarns with finite element compression behaviour analysis, and discussed to understand the mechanical performance of polymer textile composites.

The study of internal structure of woven glass and carbon fiber reinforced composite materials with embedded fiber-optic sensors

In this work, samples from composite materials with embedded optical fibers are investigated. It is known that for unidirectional layered composite materials, under certain conditions, a distortion of the internal structure and the formation of such technological defect as resin pocket in the region of the embedded optical fiber occur. So it is important to evaluate the change in the internal structure for other types of reinforcement, in particular, woven reinforcement. Analysis of the internal structure of the studied materials with 2´2 twill weave style was carried out using a digital microscope. In addition, the reflected optical signal from the Bragg gratings after being embedded into the composite material is analyzed.

Effect of particle sizes on the mechanical behaviour of limestone-reinforced hybrid plastics

The present research has been made to investigate the characteristics of a new composite material made up of limestone as particle reinforcement. New composites are made by taking limestone particles in five different sizes and jute as woven reinforcement in polypropylene matrix. Mechanical characteristics of the composites that include strengths against tension, compression, flexural, impact and hardness are evaluated and a comparative investigation is made among the composites. The effect of particle size on the properties is analysed and found that the composite with medium particle size bears the highest strength in all aspects. In addition, microscopic image analysis is carried out to investigate the distribution of particles, bonding capacity and other morphologies. The results showed that limestone will be apt particle reinforcement and its presence enhances all the characteristics of the composite.

Experimental and macro finite element modeling studies on conformability behavior of woven nylon 66 composite reinforcement

In this study, 3D hemispherical forming experiments are conducted to analyze the conformability behavior of nylon 66 plain woven reinforcements with different weft densities. To make insight into the forming process, a macro finite element model is also proposed for 3D forming of a specific woven reinforcement by using the defined ‘Fabric’ material. The results show that the proposed FEM modelling is highly correlated with experimental findings in terms of forming energy values with small and insignificant errors values, which confirm well model validity. It shows that the nylon 66 composite woven reinforcement with a lower weft density exhibits a lower forming energy (toughness) and hence a higher conformability over a hemispherical surface. On the other hand, modeling outputs clearly indicate that more wrinkling intensity appear for woven reinforcement with a higher weft density.

Buckling analysis of reinforced composite plates with a multiwall carbon nanotube (MWCNT)

Buckling analysis of mechanical structures is essential to insure stability under loading .Critical load of buckling refer to the maximum load can be withstood without losing of stability and avoid a catastrophic damage due to the collapse of columns .Improving of mechanical properties spatially those related with elastic behaviors of materials can lead to improving buckling since it can be raised the value of critical load . Nanotechnology is one of the modern methods which makes significant effects on the mechanical properties of materials. In the field of composite materials this technology leads to valuable improvements for the favorite properties. In this regard Nano composite materials are paid a spatial attention in research for the last decade. The main aim of the present work is to investigate the effect of Nano carbon weight fraction on buckling of the composite plate. Five samples of Nano composite plates were prepared and fabricated for experimental investigations .The plate samples are combined of woven reinforcement fiber and polyester matrix with Carbon .The weight fraction of Nano additives are 0 %, 0.5%, 1%, ,1.5 and 2%, of resin materials weight. To provide homogenous composite an ultrasonic homogenizer is utilized. The experimental work include buckling test for different Nano plates samples with simply supported at two ends and free at the other .Finite Element analysis was achieved via ANSYS R15.0 with proper elements ,meshing ,boundary condition and static analysis .It is found that increasing of Nano carbon weight ratio tends to increase critical load of buckling ,the maximum buckling load is at 2% wt ratio and the experimental results shows fair validation for the numerical analysis where the maximum error dos not exceeded 15% .

Experimental measurements and numerical modelling of the mechanical behaviour of a glass plain weave composite reinforcement

The study deals with the mechanical behaviour of a glass plain weave composite reinforcement. The experimental activities were focused mainly on uniaxial and biaxial extension tests. Besides, in-plane shear deformation was measured by bias extension test, and for the sake of completeness out-of-plane bending behaviour. In the numerical study, a hyperelastic constitutive model for the yarn material was adopted and validated for the meso scale prediction of the mechanical behaviour of the glass plain weave reinforcement. The model was validated for biaxial tensile and in-plane shear deformation.

Experimental, analytical and numerical investigation to prevent the tow buckling defect during fabric forming

We investigate the causes, kinematic and possible ways to prevent the tow-buckling defect during the complex shape-forming of a dry woven reinforcement. Macro-scale compression leads to wrinkles; we focus on a meso-scale phenomenon generated by a non-uniform axial compression of the tow due to in-plane bending. An experimental study is presented, followed by an efficient method to predict the onset of the tow-buckling defect. This investigation is based on the combination of an experimentally validated analytical approach, with a macro-scale simulation of the forming process for a single fabric layer. A particular focus is given to the resulting tow curvatures that allows us to predict the zones of high tow buckling probability. The relatively simple numerical approach based on Lagrange assumptions does not take into account tow slippage. However, for most cases, where buckles appear before slippage, this approach alleviates the compulsory need for an expensive meso-scale representation.

A lamination model for shape memory polymer/woven fabric composites

Based on continuum mechanics and finite element method, a lamination model was developed for shape memory polymer composites (SMPCs) reinforced by woven fabrics. SMPCs were modeled as a laminated structure with woven fabric reinforcements embedded in shape memory polymers (SMPs). Thermo-responsive SMPs were defined by a 3D phenomenological model based on the phase transition approach, while woven fabric reinforcements were characterized by an anisotropic hyperelastic model. The proposed model was validated by comparing numerical results of a SMPC in the shape memory cycle of bending deformation with experimental data. Applications of the lamination model were demonstrated on numerical simulations of a tube made of SMPC in three shape memory cycles with different deformation modes. The proposed model is simple and applicable in the simulations of various shape memory cycles related to SMPCs. It also provides a theoretical foundation for the analysis and design optimization of woven fabric reinforced SMPC structures.

Micromechanical finite element parametric study of polyamide 6 based single polymer composites reinforced by woven textile structures

This study presents a finite element-based micromechanical analysis of woven single polymer composites (WSPC), prepared by compression molding from polyamide 6 (PA6) woven fabrics powder-coated with PA6 microparticles. Initially, the PA6 microparticles (MP) were synthesized by solution/precipitation activated anionic ring-opening polymerization of ε-caprolactam. After the powder coating, the MP fraction upon each textile ply was transformed into the continuous PA6 matrix by hot pressing at a temperature lower than the melting of the PA6 textile reinforcements. Plain and satin PA6 woven fabrics were selected as reinforcements that were stretched and annealed prior to molding so as to enhance their mechanical performance. The tensile and Izod impact properties of WSPC were characterized in relation to the reinforcement architecture, fiber content and ply orientation. Finite element analysis was used for a parametric study of woven reinforcements and to correlate the deformation and stress distribution of the structures with the tensile failure of the composites. Moreover, to assess the interfacial matrix-reinforcements bonding state, a study of the surfaces fracture, obtained by SEM topography, using image processing was performed.

Impact of types of orthophthalic unsaturated polyester matrix on tensile strength of woven roving fibers as reinforcement

This paper focuses on a unique form of polyester matrix composite with woven roving fibers as reinforcing agent, replacing the conventional E-glass. The impact of different types of orthophthalic unsaturated polyester matrix and their composites on tensile strength of polyester matrix composite with woven roving fiber is investigated. Polyester matrix composite with woven roving fiber reinforcement is made by hand lay-up technique, where different types of orthophthalic unsaturated polyester matrices available in the market are used. The mechanical properties of the developed material are tested using universal testing machine, which investigated tensile strength. The BYK A-555 (coded 555) orthophthalic unsaturated polyester matrix showed 30% greater tensile strength and required least curing time as compared to other matrices, including Mc Laren S3133 (coded 3133), LUPOY-GP5300 (coded GP5300) and HSEA-LF1 (coded LF1). However, the composite of 3133 and 555 shows 50% greater tensile strength as compared to single matrix, and when all orthophthalic unsaturated polyester resins (3133 + 555 + GP5300 + LF1) are mixed together, their composite show 70% greater tensile as compared to single unsaturated polyester matrix.

Effect of Shot Peening and Solidification on Fatigue Properties of Epoxy Base Composite Material

This work evaluated experimentally the fatigue stress behavior of two types of composite material (SIR-epoxy resin with woven E-glass fiber as reinforcement and SIR-epoxy resin with random E-glass fiber as reinforcement) subjected to shot peening (2, 4 and 6 min) through three different times of solidification of samples (two, four and six days). The results show that, for woven reinforced composite, the great improvement in fatigue stress was obtained at both two and six days of solidification with (2, 4 and 6) min of shot peening times (SPTs) in which the percentage of the maximum enhancement was 59.38% in fatigue stress (at two days of solidification and 6 min shot peening time). For random reinforced composite the great improvement of fatigue stress was obtained at two and six days of solidification with (2, 4 and 6) min of shot peening times (SPTs) in which the percentage of the maximum enhancement was 33.78% (at two days solidification and 6 min shot peening). After four days of solidification, increasing shot peening time will decrease the fatigue stress for both types of composite materials (woven reinforcement and random reinforcement) and the maximum decreases in fatigue stresses at 6 min of shot peening was -43.06% and -28.9% for woven composite and random composite respectively. The tensile test and the fatigue test were done after full solidification of all the patterns.

Pull-off tests of CFRP T-joints with conventional and 3D reinforced fillets

A study of T-joints made of CFRP prepreg is presented where the joints contain either conventional uni-directional (UD) fillets or fillets with three-dimensional (3D) woven reinforcement in the joint cavity. Both pristine and impacted specimens are tested experimentally in a pull-off load case. The T-joints with UD fillets are stronger but also show greater spread in strength than T-joints with 3D fillets. The higher strength is attributed to the UD fillets’ ability to deform transversely to their length direction and efficiently adapt to the T-joint cavity before curing. The 3D fillets do not admit the same level of transverse shape adaptability and if their cross sections do not fit the geometry of the T-joint cavity sufficiently well, local stress concentrations could emerge that reduce the strength of the T-joint. The UD fillets on the other hand are believed to be sensitive to manufacturing flaws causing the greater spread in strength. That in turn is attributed to a lack of crack-arresting capability in the UD fillet. The 3D fillets however have excellent crack-arresting properties due to their multi-directional fibre architecture. With a few exceptions the impact damages did not significantly affect the strength of the T-joints tested in this study.

Engineering of three-dimensional near-net-shape weave structures for high technical performance in carbon fibre–reinforced plastics

To tap the full potential of reinforcing fibres for lightweight construction of sustainable carbon fibre–reinforced plastic components, woven three-dimensional reinforcement structures open up innovative approaches by integrating functional features. In this work, a novel three-dimensional shuttle weaving technology was taken advantage of to study carbon reinforcement structures with uninterrupted load trajectories from three points of view. Mechanical principals, economic and environmental issues were focused to provide an overall picture. Near-net-shape reinforcement fabrics with load trajectory–compliant yarn paths and interconnected layers that are interwoven in thickness direction were objects of investigation. The effects of a closed fabric selvedge, only producible by shuttle weaving, were investigated too. The here presented novel technology enables complex woven reinforcement structures that otherwise would demand several fabric layers leading to limited properties and lower performance of the carbon fibre–reinforced plastics due to missing interconnections between the layers. The studies on exemplary rods revealed a close relationship between different three-dimensional weave structures and the carbon fibre–reinforced plastic’s mechanical properties. The three-dimensional structures were woven in a single-step process and subsequently infiltrated with epoxy resin in the Vacuum Assisted Process (VAP®) and mechanically tested. Rounding off, universal guidelines for the layout of three-dimensional fabrics for rods were derived therefrom. The economic and environmental aspects of the complete process line were compared to the conventional manufacturing procedures for carbon fibre–reinforced plastic by material flow cost accounting. Looking at sustainability, material flow cost accounting showed that lightweight three-dimensional components with integrated features can be produced cost-effectively with less environmental impact by the novel weaving technology. Its capability for high-quality serial production of three-dimensional reinforcement structures is evident, which was one major result of the work.

Formability Behaviour of 3D Woven Solid Structures with Varying Stuffer Binder Ratio

Abstract In this study formability of three different Multilayer E-Glass 3D orthogonal woven preforms with varying stuffer (warp yarns) and binder (through thickness yarn) ratio is experimentaly investigated. 3D orthogonal woven reinforcements were developed using a in house fabricated mutibeam rigidrappier weaving machine. Formability behaviour of all structures were analysed using a fabricated formability fixure, with hemispherical pluger. Stuffer and binder yarn percenatge by mass were varied keeping same fiber volume fraction in all three structure, It is obsrved that binder percetage, Number of crossover point in a unit cell, singnificantly influence formability behaviour of the strucures.

KOMPARASI KEKUATAN TEKUK PADA KOMPOSIT LAMINA DENGAN MATRIK DUA JENIS KAYU DAN REINFORCEMENT BAMBU

Natural materials are environmentally friendly materials that can be made as components of matrix and reinforcement. Wood is part of the stem or branches and twigs of hardened plant due to lignification. Bamboo is a type of grass plants belonging to the order Graminae, familia Bambuseae, rooted fibers, the trunk-shaped cylinder with a diameter that varies from base to tip, hollow, hard. The composite is a composite of two or more materials that are integrated macroscopically and form a new properties. The composite type used in the laminate composite consists of two different layers of material and combined together, using adhesive, the manufacturing process using the hand lay up method. Matrix used balsa and mahoni wood, for reinforcement used type of bamboo apus molded basket woven. Bending test, using ASTM D7264 / D7264M-07 standard. The results of the experiment by testing each test, using 3 test specimens, then taken the average value. For balsa wood matrix, with plain woven reinforcement, buckling strength with value 35.60 ± 2.30 MPa, for balsa wood matrix, with basket woven reinforcement, buckling strength with value 32.64 ± 4.20 MPa. For mahoni matrix, with plain woven reinforcement, buckling strength of 55.15 ± 4.89 MPa, for mahoni matrix, with basket woven reinforcement, buckling strength of 77.15 ± 4.88 MPa. From these data shows that by using mahoni matrix the buckling strength is greater than using balsa wood matrix, either using plain or basket woven.

Prediction of Gas Permeability of Multilayer Woven Reinforcements for SiCf/SiC Porous Composites

The permeability is a key property of SiCf/SiC porous composites using as filter in high temperature. In this study, an analytical model based on Hagen–Poiseuille flow was used to investigate the relationship between the structural properties and the filtration performance of the fiber architecture, including fabric and stitched preform. The air flow through the fabric was considered in two different regions: inter-yarn and inter-fiber, as well as the pore properties of the fabrics. The key feature of the model was that the parameter of flow channel based on the pore shape was taken account into the calculation of the equivalent pore size. After determining the pore characteristics, the flow rates of the pore unit cell were obtained; subsequently, permeability of the fabrics and stitched preforms were predicted to compare with the experimental ones. This turns out that the analytical model shows a good correlation between the experimental and predicted permeability values, and the difference between different woven-type fabrics was well presented.

Hybrid approach for woven fabric modelling based on discrete hypoelastic behaviour and experimental validation

A non-linear discrete hybrid approach based on the association of hypoelastic continuous elements (non-linear shear behaviour) with specific connectors (non-linear tension stiffness) is developed. It allows the simulation of a two-dimensional (2D) woven reinforcement forming via an accurate explicit finite element analysis. This approach allows the simulation of 2D unbalanced fabrics uncoupling tensile and shear behaviour. It only needs a few parameters to be identified, and shows a good agreement with the experiments. The identification of the model parameters is investigated, and their relevance is analysed in reference tests. To determine the continuous element behaviour, a VUMAT hypoelastic model is implemented in Abaqus/Explicit. This model allows the prediction of fibre stresses and the accurate determination of shear angle in large deformations. Identification and validation of the model are performed using standard characterisation fabric tests. The experimental characterisation provided the numerical data to produce a representational prediction of the deformed fabric geometry and shear angle distribution. Further, the behaviour of the carbon woven reinforcement is identified. A bias extension test is used to both calibrate and validate the model. The capability of the model is illustrated to simulate deep drawing, and to compare with the experimental results of hemispherical forming.

Development of composites, reinforced by novel 3D woven orthogonal fabrics with enhanced auxeticity

Auxetic materials are under great attention of researchers due to their excellent mechanical response under certain conditions. Previous works have been carried out in knitted or uni-stretch woven fabrics. In the present study, three-dimensional (3D) woven structures were produced and the effect of float length of ground weave and binding yarn on auxeticity of the fabric was investigated. Eight different 3D orthogonal woven structures/reinforcements were produced on rapier dobby loom by changing the float length in ground weave and binding yarns. Hand layup technique was used for composite fabrication, while green epoxy resin was used as a matrix. For investigating the auxeticity, 3D reinforcement samples were subjected to tensile loading and change in their thickness was measured. The results showed that 3D woven reinforcements with equal and maximum float length of ground weave and binding yarn showed greater auxetic behavior, because both weaves support each other and room for opening of structure increases. As the difference between the float length of ground weave and binding yarns increases, the auxeticity of reinforcement decreases because the ground weave and binding yarn cancel out the effect of each other. Moreover, the impact energy absorption of the developed composites was found to increase with the increase in float length, justifying that the structures are auxetic in nature.

Experimental assessment of the mechanical behaviour of 3D woven composite T-joints

To understand the influence of the fibre architecture of 3D woven composite T-joints on mechanical performance, as well as the benefits that 3D woven T-joints can offer over the equivalent 2D laminates, experimental testing is performed on two types of 3D woven T-joint with only weave variation at the junction, and one type of 2D woven laminate T-joint. A quasi-static tensile pull-off loading is selected in this work as this out-of-plane load case is one of the typical loading conditions for such T-joint structures. The significant advantages of 3D woven composite T-joints in terms of ultimate strength and damage tolerance over the 2D alternative were identified in the testing. More importantly, this work showed that variation in the fibre architecture can considerably enhance properties such as delamination resistance and total energy absorption to failure, as well as increasing slightly the stiffness and initial failure load. This experimental assessment has demonstrated that using 3D woven reinforcements is an effective way to improve the load-bearing capability of composite T-joints over laminates, and also that this improvement could be optimised with regard to fibre architecture.

Multi-scale analysis of flax fibres woven fabrics for composite applications

Natural fibres are used as an alternative to man-made fibres in fibre reinforced composite materials in a variety of applications due to their good specific strength and stiffness properties and limited environmental impact. However, contrary to man-made fibres, used in the form of continuous filaments, natural fibres are extracted from plants in which they have a finite length. After their extraction form plants, they are paralyzed and twisted together to form roving or yarn. In this paper, the potential of manufacturing flax woven reinforcements optimized for composite applications is evaluated. A multi-scale analysis of the textile and mechanical properties is conducted to evaluate the impact of each transformation step and the respective contribution of fibre, yarn and fabric to the composite performance. The impact of a chemical treatment on the roving features is evaluated. Results show that this treatment doesn’t impact significantly the fibre tensile strength and stiffness and improves its weavabilty. The difference between yarn and roving is also shown regarding the weavability and their impact on the composite tensile properties. The properties of these flax reinforced composites are finally compared with those available in the open literature for similar fibre composites. A promoting conclusion is then proposed.