Reinforced Polymer Composite Materials Research Articles

Experimental Investigations of Carbon Fiber Reinforced Polymer Composites and Their Constituents to Determine Their Elastic Material Properties and Complementary Inhomogeneous Experiments with Local Strain Considerations

Composite materials, such as fiber reinforced polymers, become increasingly important due to their excellent mechanical and lightweight properties. In this respect, this paper reports the characterization of a unidirectional carbon fiber reinforced polymer composite material. Particularly, the mechanical behavior of the overall composite and of the individual constituents of the composite is investigated. To this end, tensile and shear tests are performed for the composite. As a result, statistics for five transversely isotropic material parameters can be established for the composite. For the description of the mechanical properties of the constituents, tensile tests for the carbon fiber as well as for the polymer matrix are carried out. In addition, the volume fraction of fibers in the matrix is determined experimentally using an ashing technique and Archimedes’ principle. For the Young’s modulus of the fiber, the Young’s modulus and transverse contraction of the matrix, as well as the volume fraction of the constituents, statistics can be concluded. The resulting mechanical properties on both scales are useful for the application and validation of different material models and homogenization methods. Finally, in order to validate the obtained properties in the future, inhomogeneous tests were performed, once a flat plate with a hole and a flat plate with semicircular notches.

Estudio comparativo de las propiedades mecánicas de materiales compuestos de fibra de carbono para el desarrollo de elementos estructurales aeronáuticos.

  Carbon fibre reinforced polymer composite material structures continue to be, despite the tremendous technological maturity achieved in recent decades, one of the most promising options to address the challenges of the aeronautical industry with respect to behaviour in the face of efforts such as improvements, regarding weight or costs. Ongoing demands to address major societal challenges, promote industrial leadership in Europe, and address aviation decarbonisation for the purpose of protecting the environment drive the demand for more optimal materials designed to improve these aspects. The previous tasks carried out to complete the test campaign will be described, showing its plan and design, details of preparation, assembly of the specimens and the execution of the tests. The philosophy proposed by Airbus (ADS) is presented with the consolidation of admissible design against alterations of the material that could realize its evolution or arise in the manufacturer's batches. Observing changes in the material, leading to the improvement of its mechanical and handling characteristics, a comparison has been made by Airbus with the one used previously for the determination of admissible design. It is intended to incorporate assessments of effects associated with the process of its industrialization. Once the results and analyzes are available, the normalized results of the conclusions would be presented. The activity carried out is included within the CERES project (Advanced Rear End Structural test program), belonging to the Clean Sky 2 Joint Undertaking European research aeronautical program.

Flexible photonics in low stiffness doped silica for use in fibre reinforced polymer composite materials

The production of a flexible photonic device in doped silica with a Young's modulus that is significantly less than that of traditional silica glass is described. Here the purpose of reducing the modulus is to make planar sensors more applicable for integration into fibre reinforced polymer composite structures. The flexible planar substrate (58 μm thick) consists of three doped silica layers, fabricated using sacrificial silicon wafer processing. It is demonstrated that a Young's modulus of around 40 GPa can be achieved in comparison to a value above 70 GPa for typical silica glass. The optical response of a few mode waveguide that is direct UV written within the central core layer of the flexible glass platform is described. The mechanical stiffness of the platform is determined using nano-indentation tests and confirmed in mechanical tests that demonstrate clearly the flexible nature of the platform. To assess usability for applications integrated into structures undergoing mechanical loading the fatigue lifetime for one million bending cycles is investigated. No degradation to the optical response was observed under the performed testing.

Prediction of impact performance of fiber reinforced polymer composites using finite element analysis and artificial neural network

In this study, a methodology combining finite element analysis (FEA) and artificial neural network (ANN) through multilayer perceptron architecture was utilized to predict the impact resistance behavior of hybrid and non-hybrid fabric reinforced polymer (FRP) composites. A projectile at 250 m s−1 impact velocity was considered for the high velocity impact simulations. The Kevlar, carbon and glass fabric-based epoxy composites were modelled and the impact tests were performed through finite element simulations. The residual velocity results from FEA were used as training data for the ANN prediction. The ANN predicted results were in good agreement with FEA results with a maximum variation of about 6.6%. In terms of impact resistance, composite laminates with more Kevlar layers exhibited enhanced performance compared to other samples. Neat Kevlar/epoxy (K/K/K) exhibited the best impact resistance performance in terms of lowest residual velocity and highest energy absorption of 101.84 m s−1 and 222.86 J, respectively. Whereas, neat glass/epoxy (G/G/G) specimens registered the highest projectile residual velocity (165.13 m s−1) and lowest energy absorption (158.99 J) compared to all other specimens. 2-fabric sandwich composite K/G/K exhibited a low residual velocity of 115.27 m s−1 and high energy absorption of 218.53 J, which is the second best among all specimens. Comparatively, the 3-fabric hybrid composites registered intermediate impact resistance results lower than that of Kevlar rich specimens, but significantly higher than neat G/G/G composite, thus, proving the effectiveness of hybridization in enhancement of impact performance compared to neat glass composite. Overall, the chosen methodology yielded significantly accurate results for the prediction of impact behavior of FRP composites.

Analysis of surface integrity in drilling carbon fiber reinforced polymer composite material under various cooling/lubricating conditions

Carbon Fiber Reinforced Polymer (CFRP) composite materials are a class of advanced materials widely used in versatile applications, including aerospace and automotive industries, due to their exceptional physical and mechanical properties. Owing to the heterogeneous nature of the composites, it is often a challenging task to machine them unlike metals. Drilling in particular, the most commonly used process for component assembly, is critical especially in the aerospace sector that demands parts of highest quality and surface integrity. Conventionally, all composites are machined under dry conditions. While there are drawbacks related to dry drilling, for example, poor surface roughness, there is a need to develop processes that yield good quality parts demonstrating improved surface integrity. This study aims at investigating the machining performance when drilling CFRP composite material under cryogenic (Cryo), minimum quantity lubrication (MQL) and hybrid (CryoMQL) conditions and comparing the performance with dry drilling in terms of the thrust force, torque, delamination, geometric error such as diametric variation, and surface integrity assessment including average surface roughness, hardness and sub-surface damage analysis. Additionally, the effects of varying the feed on the drilling performance were examined. Based on the results, it was concluded that drilling of CFRP composite material using coolant/lubricant outperformed dry drilling by producing better quality parts. Also, varying the feed proved to be advantageous over drilling at constant feed.

Analysis and prediction of woven fabric design impact on fabric/polymer composite drilling energy

Damage, generated during drilling processes, will affect the material integrity and further delamination through the fiber-reinforced composite cross-section. Drilling is necessary for the assembly processes of composite parts. This article deals with the effect of the weave parameters on the drilling mechanism. The mechanism of the yarn shearing ring drilling was investigated, and the quality of the drilled hole was carefully examined for different drilling conditions. Set up for measuring the power consumption during the drilling of different samples as well as the value of the thrust force was constructed. In the drilling of fabric-reinforced polymer composite, the torque, thrust force, and delamination factor are depending directly on fabric design parameters. It was shown that both, drilling power and drilling thrust force, are proportional to the total specific fabric stiffness. Delamination caused by drilling thrust is one of the most problematic defects after drilling laminate composite. A drilling Index was developed and could be used to evaluate the effect of the fabric design of laminate on its composite drilling performance. It was revealed that significantly higher drilling power is needed for the plain weave fabric design than for the other fabric designs of the same unit repeat as well as for the laminates of high fiber volume fraction and high total flexural rigidity. Analysis of the delamination factor and the drilling power showed a high correlation with total fabric flexural rigidity.

ISOLATION AND CHARACTERIZATION OF CELLULOSE FROM Pentaclethra macrophylla Benth POD BIOMASS WASTES FOR POLYMER REINFORCEMENT COMPOSITE

The interest in natural reinforced polymer composite materials is rapidly growing both in industrial and basic research applications. This is based on its availability, renewability, low density, cheapness, biodegradability, and satisfactory mechanical properties. The research reports on the isolation and characterization of cellulose from Pentaclethra macrophylla Benth Pod (PMBP) biomass wastes for polymer reinforcement composites. Cellulose was successfully isolated from PMBP biomass via delignification and bleaching. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectrometry (FTIR), thermal gravimetric analysis (TGA), and deformation gravimetric analysis (DGA) were used to characterise the raw and isolated cellulose. The isolated cellulose has better thermal stability, crystallinity, and porosity than the raw cellulose. The removal of the matrix material (most hemicelluloses and almost all the lignin) led to an increase in the crystallinity and the maintenance of the thermal stability of the cellulose. The functional group elucidation showed that both raw and isolated contained cellulose, the morphology of the cellulose revealed some essential elements that are suitable for good polymer reinforcement composites. The obtained cellulose could serve as a reinforcing material in composite products or as a raw material for other applications.

Mechanical characterization and low-velocity impact behavior of flax woven fabric-reinforced polymer composites

Man–made fibers like carbon or glass are main components for fiber-reinforced polymer composites thanks to their high strength and stiffness values. However, man-made fibers are not eco-friendly and can hardly be recycled in the nature. Using a high amount of man-made fibers threatens our nature and poses a significant risk for the future of world. Natural fiber reinforced composite (NFRC) is considered as a good alternative for traditional composites. Therefore, NFRC has been examined to develop materials, which have comparable mechanical properties with the man-made fiber reinforced composites, for last decades. Although lots of studies were carried out on the mechanics of NFRC, a few of them focused on the structural design of reinforcement and their effects on composites performance. In this study, the number of weft densities of reinforcements were differentiated and their effects on the mechanical properties of composites were investigated. Fabrics were produced from flax yarns and composites were manufactured by vacuum assisted resin infusion molding method. The tensile, compression, shear and impact tests were carried out to characterize the manufactured composites. Results show that while increasing number of weft density of reinforcement improves the tensile and compressive strength of NFRC in the weft direction, the tensile strength and elastic modulus of composites in the warp direction were characterized by the crimp percentage values of warp yarns. Moreover, it was determined that the number of weft density in the reinforcement affect the contact force and energy absorption capacity of NFRC.

Modelling and Analysis of CNC Milling Machine Bed with UHM CFRP composite Material

Abstract: Structural materials are used in a machine tool have a key role in defining the productivity, accuracy and Size proportions of the part manufactured by machine tool. The conventional structural materials like cast iron and Stainless or carbon steel at high operating speeds but used in precision machine tools grow positional errors due to the vibrations transferred into the Machine tool structure. Faster cutting speeds can be achieve only by structure which has good damping characteristics and high stiffness. Clearly the life of a machine tool is proportional to the levels of vibration Produce by machine. The further Work is carried out to Study the deformation and natural frequency using Static analysis and Modal analysis respectively. The bed in machine tool Took Major role in the precision in components. It is one of the greatest vital tool structures which is absorb the vibrations resultant from the cutting operation. To analyse the bed for possible material changes and Structure changes that could increase stiffness, decrease weight, expand damping characteristics and segregate natural frequency at the operating range. So main enthusiasm behind the impression to go for a composite Material in model involving ultra-High Modulus Carbon Fibre Reinforced Polymer Composite Material (UHM CFRP). In a carbon has good stiffness and strength properties but its absences in damping requirements. On the other hand, polymers, though its deficiencies in strength but, good damping in characteristics and it is easily holding the carbon fibres. So, this is makes greatest combination of materials in an appropriate manner. In this work, a machine tool’s bed is selected for the analysis static loads. Then study is carried out to decrease the weight of the machine tool’s bed without affecting its structural rigidity. The 3D CAD model of the bed has been created by using commercial 3D modelling software and analyses were carried out using ANSYS 2021 R2. Keywords: Composite material, hybrid structures, Milling machine bed, UHM CFRP.

The Investigation the thermal characteristics of polyphenylene sulfides

The article presents the results of a study of the chemical structure, low molecular weight impurities and heat stability according to TGA/DTA of domestic polyphenylene sulfides (PPS) with different molecular weight and their imported analogues. It is shown that domestic samples are almost identical to imported analogues and can be used as a binder for highly filled reinforced polymer composite materials for structural purposes.

Investigation of electrical and electromagnetic properties of quartz fiber reinforced polymer composite material by using modified paints with carbon nanoparticles (graphene/double-walled carbon nanotube)

Composite materials have many features to contribute to aircraft design but have low electrical conductivity. In this study, it is aimed to increase the electrical conductivity of FRP (Fiber Reinforced Polymer) composites used in different parts of the aircraft. The modified nanoparticles were added into the aircraft paint and applied on the composites used in the radome part of the aircraft, and it is aimed to either increase or keep the electromagnetic permeability stable. Firstly, the surfaces of the FRP composite samples were painted by Graphene and Double-Walled Carbon Nanotube (DWCNT) to reinforce the conductive nanoparticles at different ratios. Resistance measurements of the samples were made according to the Airbus “Electrical Surface Resistance Measurement” procedure and their electrical conductivity was calculated. The Non-Contact Measurement Method test setup was used to obtain information about the electromagnetic properties of the samples. As a result of the measurements, N3 (σ = 4.37x10−4 S/m, S21 = −15.81 dB) sample conforms the best with the objectives of ourstudy compared to electrical conductivity (N0, σ = 4.83x10−5 S/m) and electromagnetic permeability (N0, S21 = −15.83 dB) of the reference sample. The contact angle measurements were taken to determine the contact angle changes depending on the surface morphology and conductivity changes of the samples painted with different and varying amounts of nanoparticle doped paint. Additionally, measurements were taken with the FTIR-ATR instrument to make surface analysis of the samples.

Experimental and numerical investigation of damage evolution in carbon fiber reinforced polymer stiffened panel in post-buckling regime

Stiffened composite panels have been extensively used thanks to their ability to withstand high load and large deflection. However, their nonlinear behavior and complex damage modes during the post-buckling regime remain challenging and still require research work to improve understanding. In the current study, the buckling and post-buckling responses of a hat-stiffened panel made with carbon fiber reinforced polymer composite material are investigated experimentally and numerically with identifying the damage process and its effect on the panel stiffness. The experimental analysis is achieved by performing quasi-static multi-step compressive loading up to failure with full displacement assessment. A Structural Health Monitoring strategy is also deployed for registering and localizing the Acoustic Emission (AE) activities during each run. Matrix data extracted from the AE waveforms are processed and classified with respect to damage mechanism. Additionally, this research proposes predictive Finite Element Model based on Progressive Failure Analysis. Modified Chang-Chang failure criteria is adopted and implemented using Ansys Usermat subroutine. Numerical and experimental data have been compared and good agreement is demonstrated.

Experimental and finite element study on high-velocity impact resistance and energy absorption of hybrid and non-hybrid fabric reinforced polymer composites

High-velocity impact resistance of FRP composites consisting of Kevlar, carbon and glass in hybrid and non-hybrid stacking sequences was studied through experimental and finite element analysis. Neat Kevlar/epoxy and Kevlar/glass/epoxy sandwich composites have the 1st and 2nd highest impact energy absorption percentage (100% and 97.99%, respectively). Carbon/epoxy composite exhibited the least energy absorption (38.78%). Other hybrid composites showed intermediate values of energy absorption in the range 38.58%–44.11%. Hybridization did not show any improvement in interlaminar shear strength of composites either. However, hybridizing Kevlar based composites with glass in the middle layer offered impact resistance close to Kevlar/epoxy composite while offering a 21% saving in material cost. Thus, such Kevlar and glass fabric-based sandwich composites possess a great potential as protective structures due to their ability to withstand impacts up to 200 m.s−1 velocity. These composites may also be considered for development of protective armor that are light-weight compared to conventional materials and more affordable. Finite element simulation results are in good agreement with that of experimental results with differences below 14%.

Influence of Woven-Fabric Type on the Efficiency of Fabric-Reinforced Polymer Composites.

The greatest advantage of fiber-reinforced composite materials is the freedom to tailor their strength and stiffness properties, while the most significant disadvantage consists in their high costs. Therefore, the design process and especially the optimization phase becomes an important step. The geometry of the fabric of each lamina as well as their stacking sequence need to be carefully defined, starting from some basic geometric variables. The input parameters are the widths and the heights of the tows, the laminate-stacking sequence and the gaps between two successive tows or the height of the neat matrix. This paper is a follow-up to a previous work on using and improving an in-house software called SOMGA (Satin Optimization with a Modified Genetic Algorithm), aimed to optimize the geometrical parameters of satin-reinforced multi-layer composites. The final goal is to find out the way in which various types of woven fabrics can affect the best possible solution to the problem of designing a composite material, able to withstand a given set of in-plane loads. The efficiency of the composite structure is evaluated by its ultimate strains using a fitness function that analyses and compares the mechanical behavior of different fabric-reinforced composites. Therefore, the ultimate strains corresponding to each configuration are considered intermediate data, being analyzed comparatively until obtaining the optimal values. When the software is running, for each analysis step, a set of intermediate values is provided. However, the users do not have to store these values, because the final result of the optimization directly provides the composite configuration with maximum efficiency, whose structural response meets the initially imposed loading conditions. To illustrate how the SOMGA software works, six different satin-woven-fabric-reinforced composites, starting from plain weave (satin 2/1/1), then satin 3/1/1, satin 4/1/1, satin 5/1/1, satin 5/2/1 and finally satin 5/3/1, were evaluated in the SOMGA interface. The results were rated against each other in terms of the composite efficiency and the case characterized by minimal reinforcement undulation (thinnest laminate) were highlighted.

Research progress of carbon materials in the field of three-dimensional printing polymer nanocomposites

Abstract Three-dimensional (3D) printing technology is an additive manufacturing technology designed to rapidly process and manufacture complex geometrical components based on computer model design. Based on a 3D data model, materials are accumulated layer by layer through computer control, and the 3D model is finally turned into a stereoscopic object. Compared with traditional manufacturing methods, 3D printing technology has the advantages of saving man-hours, easy operation, no need for molds, and strong controllability of component geometry. With the development of this technology, according to the core materials and equipment and other elements of the printing molding technology, several types of 3D printing technologies such as fused deposition modeling, selective laser sintering, stereolithography, and solvent cast-3D printing have gradually formed. This review focuses on the principles and characteristics of several of the most representative 3D printing molding processes. And based on carbon nanomaterial (carbon fibers, graphene, and carbon nanotubes) reinforced polymer composite materials, the research progress of different 3D printing molding processes in recent years is reviewed. At the same time, the commercial application of 3D printing molding process in this field is analyzed and prospected.

Experimental investigation on mechanical, thermal behaviour and characterisation analysis of aquatic waste water hyacinth plant fibre, powder and ash reinforced polymer composite material – Dangerous aquatic threat into successive product approach

The purpose of this study is to investigate the mechanical and thermal properties of aquatic wastewater hyacinth plant natural power, ash and fibre reinforced polymer composite samples. This work is primarily concerned with creating sustainable products from this aquatic waste in a sustainable manner. Hyacinth plant fibres, powders and ash particles are used in this work as reinforcement material for composite samples, which are made by utilising the hot press compression moulding technique and epoxy matrix. In this study, new mechanical way of fibre extraction process is used to extract the fibres of the water hyacinth. Mechanical strength and thermal properties thermo gravimetric analysis, differential thermo gravimetric, thermo gravimetric peaks of hyacinth composite samples are evaluated. Fourier Transform Infrared Spectroscopy and X-ray diffraction techniques are used to characterise the hyacinth composite. A scanning electron microscope is used to examine the fractured surfaces of hyacinth composite sample samples. By using this technique, fibre clusters, fibre fractures and fibre pull-outs can be identified. Waste management and waste recycling concepts are heavily influenced by this manuscript. The zero-waste concept has been achieved through this work. According to all the findings of this study, the natural plant fibres from the water hyacinth plant and ash particles can be used as reinforcement materials in conjunction with an epoxy resin matrix for making lightweight particleboard products and other lightweight materials in general.

A vision for a lightweight railway wheelset of the future

Rail vehicle lightweighting using fibre reinforced polymer composite materials is essential for the future of rail. This is recognised as a means of reducing carbon dioxide production through lower energy consumption, as well as reducing the impact on track degradation, thus delivering improved rail capacity and performance. This paper presents an overview of the work conducted within work package three of the NEXTGEAR project focused on the ‘wheelset of the future’. Three concepts for a hybrid metallic-composite railway axle are proposed and their strengths and weaknesses are assessed. A finite element analysis on the selected concept was conducted, including a solution for the bonded joints of the metallic collars which provide the interface to the wheels and bearings. An axle mass reduction of over 63% was shown. An overview is also provided regarding the analysis of manufacturability of the axle, non-destructive methods for axle inspection/structural health monitoring and effects of impacts from ballast stones. Finally, a preliminary evaluation of the benefits arising from the reduction of the unsprung masses is provided, based on multibody simulations of vehicle dynamics.

Ballistic response of woven glass fabric-epoxy composites at low temperatures: Experimental investigation

The ability of Glass Fabric Reinforced Polymer (GFRP) composites in arresting a projectile during a ballistic impact is dependent on climatic conditions such as temperature since their mechanical properties vary with the same. In the present work, ballistic impact experiments were carried out on plain weave GFRP composites to evaluate their performance in low-temperature environments. Square sheets of plain weave GFRP were impacted by cylindrical projectiles at four different temperatures viz. -35°C, -15°C, 0°C, and at Room temperature. A gas gun was used to propel the projectiles and the velocities were measured using a High-speed camera while the temperatures were monitored using a Resistance Temperature Detector (RTD). Strain gauges were also attached at different locations on the samples to quantify the strains due to the projectile impact. The ballistic limit obtained from the test data was found to increase linearly with reducing temperature contrary to the general expectation of degradation in the ballistic performance of GFRP at low temperatures. The Lambert-Jonas equations were fit to the experimental data and the parameters were estimated. The results obtained also indicated a decrease in stress wave attenuation and an increase in tensile strains with the decrease in temperature.

Preparation and Testing of Carbon Fiber Reinforced Composites Embedded with Lithium-Ion Polymer Batteries

Vehicle lightweight promises to drive down the maintenance quality and increase energy efficiency in transportation with the safe and strength performance. The use of fiber reinforced polymer composite materials structural battery vehicles is recognized as an essential enabling technology for achieving high bearing capacity and energy storage capacity. At the same time it improves the energy storage capacity, the overall structural energy storage and space utilization of new energy vehicles. In this study we bring an idea to fabricate composites with integrated lithium-ion pouch batteries. The whole preparation process was carried out at room temperature to prevent thermal damage on battery. Experimental results indicate that the cyclic working voltage and capacity of CFRP structure battery are basically consistent with the monomer lithium-ion polymer battery which obtained from Xinwei battery testing equipment. Therefore, the fabrication process does not damage the lithium-ion polymer battery.

Thermodynamic simulation, surface morphology and bending property of carbon fiber reinforced polymer composite material subjected to laser cleaning

Carbon fiber reinforced polymer (CFRP) has been regarded as an important candidate as structural components in structural engineering. With purpose of removing the epoxy resin and contaminants and in turn enhancing the bonding strength between CFRP and other materials, a nanosecond laser was used to remove the epoxy resin and contaminates on CFRP composites. A thermodynamics model was established to investigate the temperature field distribution, influences of laser power density and laser scanning speed on the cleaning effect, and therefore provide theoretical reference for cleaning experiments. The results showed that the laser power density of 8.8 kW.cm−2 and scanning speed of 1000 mm/s are preferred for an excellent cleaning effect. The cleaned surface presented a higher surface free energy, which in turn improved the tensile shear strength and bending strength. The failure mechanisms for the joints between TC4 and CFRP depend on laser power density for laser cleaning treatment.