Carbon Fiber Composite Materials Research Articles

Investigate the mechanical strength of laminated composite carbon fiber with different fiber orientations by numerically using finite element analysis

The main objective of this study is to investigate the effect of fiber orientation on the mechanical property of carbon fiber composite material under the tensile loading condition and the dynamic response analysis using finite element analysis. In composite material analysis, the lamina or ply level is considered a microscale, and the laminate level is considered a macroscale. In this work, the modeling of laminated carbon fiber composite material has been done in Ansys ACP. The lamina thickness of carbon fiber/epoxy is taken 0.5 mm and the fiber orientation is considered 0°, 30°, 45°, 70°, 90°, and the stacking sequence are [0°]12, [30°]12, [45°]12, [70°]12, [90°]12 which are considered as the unidirectional lamina. The static structure analysis has been accomplished to find out the von mises stress, total deformation, and equivalent elastic strain under the tensile loading conditions, and modal analysis is carried out to find out the natural frequency. From the simulation, this study shows that the 0° fiber orientation carbon fiber composite material has better mechanical strength compared to 30°, 45°, 70°, and 90° fiber orientation, and the natural frequency is maximum for 0° fiber orientation carbon fiber composite compared to other fiber orientations.

Comparative study of the explosive blast resistance of metal and composite materials used in defence platforms

Naval ships, military aircraft and land defence platforms are mostly constructed using steel, aluminium alloy, carbon fibre composite and/or glass fibre composite materials. Defence platforms are at risk from shock wave loads generated by explosive events, and therefore it is imperative that the construction materials are resistant to blast-induced deformation and damage. A comparative assessment is presented into the dynamic deformation and damage of metals and composites representative of naval construction materials when subjected to explosive air blasts. Flat plates of equal thickness (4 mm) or plates of similar areal density (in the range 6.2–9.2 kg/m2) made of the four materials were subjected to explosive blasts. Experimental blast testing and finite element (FE) modelling revealed that when the plate thickness was the same (4 mm) then the steel experienced less deformation (by ∼50–60%) and plasticity than the aluminium alloy due to its higher mechanical properties. The steel and aluminium plates were more resistance to blast-induced deformation (by up to ∼260–320% and ∼130–145% respectively) than the composite materials of the same thickness (4 mm). However, when the materials are compared on similar areal density, which is critical for lightweight design, the blast performance of the composite materials was similar to aluminium alloy and superior to steel. Deformation of the steel was up to 50% higher than the other construction materials, with the percentage increase rising with blast impulse.

A finite element analysis of load distribution during donning and orthostatic posture in the ITOP hybrid subischial socket.

Pressure and shear stresses applied to the stump of a transfemoral amputee wearing a newly designed prosthetic socket have been analyzed by a finite element modeling approach. The new socket was developed by the Istituto Tecnico Ortopedico Preneste, and it was named the "hybrid subischial socket." This work aimed at understanding the loads' distribution on the stump surface in 2 operative conditions: at the end of the wearing phase and during the orthostatic posture. The model of the stump was composed of 4 different materials: the femoral bone, the muscle tissue, the fat, and the skin layers. Except for the bone (rigid), the biological tissues were modeled as Neo-Hookean, and their mechanical properties were taken from the literature. The socket was composed of a containment frame, made of carbon fiber composite material, a shell made of flexible silicone, and a liner made of hyperelastic silicone. The results of our simulation show that the main support areas are located in a proper position, in agreement with the ideal principles of this prosthetic design, and the maximum pressures are well below the pain threshold reported in the literature for the same contact areas. We can conclude that although the upper rim of the socket is well below the ischiatic area, the new socket design allows for a safe and comfortable support of the body weight. This is in agreement with the evidence of a good functionality and acceptance of this prosthetics gathered in the many real applications.

Machine learning-based damage sensing and self-healing of carbon fiber/nylon composites via addressable conducting networks

In this work, addressable conducting network (ACN) was used for the damage sensing and self-healing of continuous carbon fiber reinforced nylon composite (CFRP). The machine-learning was used for accurate damage sensing by training the resistance change of composites along ACN due to their structural damage. Also, self-healing of the carbon fiber composite material was performed by applying the electrical current to generate local heating through the detected damage location. The self-healing conditions such as the current input pairs of ACN and amount of the electrical current were determined through the artificial neural network (ANN)-based machine-learning technique. As a result, high-accuracy damage sensing based on machine learning with ACN was conducted, and self-healing with a healing efficiency of 98% could be achieved.

Mechanical properties research of carbon fibre composites incorporating nanoclay and graphene

Study purpose is to determine the interactions between the widely-used graphene and nanoclay on carbon fiber composite materials. They are produced using the vacuum infusion method by reinforcing the nanoclay and graphene, which have a montmorillonite structure organized at various ratios via homogenizer, into the resin that is to be applied to carbon fiber layers. Eczac?ba?? EsanNANO 1-140 was used as nanoclay, and GRAFEN NG5 of the Nanografi Co. Ltd. was used as graphene. The graphene ratio was kept constant by taking reference from antecedent studies. Tensile test was applied to the produced samples. Graphene in the resin is expected to increase the saturation in the layers and improve mechanical properties. After nanoclay ratio exceeds a certain limit, it acts negatively rather than positively in the tensile test, their cracked roads are then rendered easier to traverse by them combining. This is why there is a certain bell-shaped curve in the strain values measured in samples. The result that gives the optimum values is sought after. Additionally, there are studies previously conducted with polymer matrix composite, from which samples that could reach to certain strains or to higher yield stress values in certain intervals are obtained. By increasing the strength and toughness of the graphene and nanoclay resin, they gain more rigidity, which raises an expectation of increment to be observed in the yield and tensile strengths.

Damage-failure transition staging in carbon fiber composite materials under quasistatic and cyclic loading with acoustic and digital image correlation analysis

Damage-failure transition staging in carbon fiber composite materials under quasistatic and cyclic loading with acoustic and digital image correlation analysis

Optimisation of Highly Efficient Composite Blades for Retrofitting Existing Wind Turbines

Currently, wind energy, a reliable, affordable, and clean energy source, contributes to 16% of Europe’s electricity. A typical modern wind turbine design lifespan is 20 years. In European Union countries, the number of wind turbines reaching 20 years or older will become significant beyond 2025. This research study presents a methodology aiming to upgrade rotor blades for existing wind turbines to extend the turbine life. This methodology employs blade element momentum theory, finite element analysis, genetic algorithm, and direct screen methods to optimise the blade external geometry and structural design, with the main objective to increase the blade power capture efficiency and enhance its structural performance. Meanwhile, the compatibility between the blade and the existing rotor of the wind turbine is considered during the optimisation. By applying this methodology to a 225 kW wind turbine, an optimal blade, which is compatible with the turbine hub, is proposed with the assistance of physical testing data. The optimised blade, which benefits from high-performance carbon-fibre composite material and layup optimisation, has a reduced tip deflection and self-weight of 48% and 31%, respectively, resulting in a significant reduction in resources, while improving its structural performance. In addition, for the optimised blade, there is an improvement in the power production of approximately 10.5% at a wind speed of 11 m/s, which results in an increase of over 4.2% in average annual power production compared to the existing turbine, without changing the blade length. Furthermore, an advanced aero-elastic-based simulation is conducted to ensure the changes made to the blade can guarantee an operation life of at least 20 years, which is equivalent to that of the reference blade.

Parallel optimization of design and manufacturing—Carbon fiber battery pack for electric vehicles

According to the requirement of “structural design and manufacturing feasibility” of the electric vehicle battery pack, the design of carbon fiber composite material instead of metal material is studied in this paper. Firstly, the cross-section performance of the composite battery pack was determined by the principle of equal stiffness. Moreover, the different layups were verified from a manufacturing point of view and the advantages and disadvantages of the three improvements, linear shear, V-shear, and V-shear + linear shear, were compared. Secondly, the three steps of free size optimization, size optimization, and layup sequence optimization were carried out for the lower box to find the lightest structure; the upper box was directly reinforced with a “King” type to alleviate the excessive amplitude. The total mass of the final pack is 14.09 kg, with a weight reduction rate of 56%. Finally, the volume-of-fluid (VOF) method in ANSYS Fluent is chosen to simulate the curing process. The molding results of four injection methods are discussed, while resin viscosity and pressure are considered to find the optimal process parameters. The work in this paper provides a reference for the lightweight application of composite materials in new energy vehicles.

Design, molding, manufacturing and testing of wave-transparent functional composite missile wings

In this paper, a fiber-reinforced resin matrix composite missile wing with a wave-transparent function is studied, which has the function of wave-transparent and meets the requirements of the mechanical properties of the missile during flight, and the missile wing structure is made of aluminum alloy, carbon fiber composite material, and glass fiber composite material, and the weight reduction is about 30.3% compared with the overall aluminum alloy structure of the missile wing. In the design process, the finite element simulation method is used, the plastic deformation of aluminum alloy is fully considered, and the antenna is built into the airfoil of glass fiber composite material, which successfully realizes the wave-transparent function of the missile wing and provides a new design idea for the composite wing.

Self-healing, reprocessable, degradable, thermadapt shape memory multifunctional polymers based on dynamic imine bonds and their application in nondestructively recyclable carbon fiber composites

Traditional epoxy thermosets have been extensively used in many fields, including the field of carbon fiber composite materials, which is favored by a large number of researchers. But they usually cannot be recycled under mild conditions. To make matters worse, the material loses its usefulness once it is damaged. Self-healing and degradable thermosetting resins with dynamic covalent bonds offer a potential solution to this conflict. In this paper, a series of epoxy polymers named EPCN based on dynamic imine bonds were easily prepared by a one-pot method using inexpensive industrial materials terephthalaldehyde and common bisphenol A diglycidyl ether as raw materials, which were cured by D230. The results show that the materials exhibit certain self-healing, reprocessability and thermadapt shape memory properties due to the dynamic properties of the imine bonds. Moreover, EPCN epoxy polymers can be degraded due to the hydrolysis of dynamic imine bonds, and their degradation exhibit temperature and acidity dependence. More importantly, the recyclable carbon fiber reinforced polymer composites prepared with EPCN-4 as the resin matrix can be completely degraded under weak acid conditions, leading to the ready and non-destructive recycling of its carbon fiber composite. We envision this reprocessable and degradable carbon fiber-reinforced composite material with cheap raw materials, simple process, and suitable for mass production will make it a potential candidate for sustainable structural material applications.

Joining processes of CFRP‐Al sheets in automobile lightweighting technologies: A review

AbstractAccording to the development trend of modern car body, the future car body will be composed of steel, aluminum‐magnesium alloy, plastic, carbon fiber reinforced polymer (CFRP), and other lightweight materials. Hybrid material body represents the latest development trend of car body structure in the future. With the development of lightweight technology, the application of carbon fiber composite material in automobile bodies is increasing due to its exceptional performance. Therefore, the joining of carbon fiber sheets with dissimilar sheets process in the hybrid material body is a key technical problem that needs to be solved. In this paper, the existing joining processes of adhesive process, mechanical joining, welding process, and hybrid joining for carbon fiber composites are reviewed; the principle, development, advantages, and shortcomings of each process for carbon fiber composites joining processes are systematically described; and the latest progress of the joining process are introduced. The purpose is tantamount to broaden the application range of carbon fiber sheets with dissimilar sheets and provide reference for its extensive application in the development of hybrid car body and lightweight.

Novel Thermoplastic Composites Strengthened with Carbon Fiber-Reinforced Epoxy Composite Waste Rods: Development and Characterization

The increasing use of carbon fiber and epoxy resin composite materials yields an increase in the amount of waste. Therefore, we present a solution consisting of composites manufactured by hot pressing, employing polyamides (either PA11 or PA12) and a mechanically recycled carbon fiber-reinforced polymer (CFRP) as reinforcement. The main objectives are to study the manufacturing of those composites, to evaluate the fiber distribution, and to perform a mechanical, dynamical, and thermomechanical characterizations. The X-ray micro-computed tomography (μCT) shows that the fibers are well-distributed, maintaining a homogeneous fiber volume fraction across the material. The variability in the results is typical of discontinuous fiber composites in which the fibers, although oriented, are not as homogeneously distributed as in a continuous fiber composite. The mechanical and dynamic properties barely differ between the two sets of composites. A dynamic-mechanical analysis revealed that the glass transition temperature (Tg) increases slightly for both composites, compared to the polymers. These results illustrate the viability of the recycling and reuse route for preventing the deterioration of carbon fibers and promoting the subsequent reduction in the environmental impact by employing a thermoplastic matrix.

An efficient stiffness degradation model for layered composites with arbitrarily oriented tunneling and delamination cracks

A periodic 2D finite element model is proposed to identify the axial and transverse stiffness degradation for arbitrarily oriented parallel tunneling cracks. This is achieved with a recently developed off-axis framework taking the 3D deformation into account via a special kinematic formulation. The proposed model is successfully validated against a variety of cases from the literature. Not only is the model capable of accurately predicting what previously was only possible with expensive 3D models or complex analytical methods, but at the same time, it is achieved with remarkably small finite element models which only take seconds for each simulation. A parametric study, shows that by including frictionless contact between the crack surfaces, a significant effect on the stiffness degradation is present for carbon fiber composite materials for off-axis orientations below 40°. An effect not seen for the analyzed glass fiber composites. In addition, based on the axial and transverse stiffness degradation, a method is proposed from which the amount of simultaneous tunnel cracking and delamination can be predicted. A Fortran-based user subroutine and supplementary Python scripts for the commercial finite element code Abaqus are made available as a co-published data-repository reference.

The Application of New Energy Materials in New-energy Vehicle

Climate change is becoming one of the biggest environmental challenges in the 21st century. New-energy vehicle produce less greenhouse gases as compared to the traditional vehicles with internal combustion engines. New energy vehicles have great potential to successfully address the issue of climate change. Additionally, new energy materials can also be used in automotive lightweight technology. This paper discussed the currently lightweight materials including high-strength low-alloy steel (HSLA), carbon fiber composite material, and modified plastics. According to the discussion in this paper, high-strength low-alloy steel can be used in automotive safety parts, chassis, and body. Carbon fiber composite materials can be used in car bodies, chassis, roofs, doors, head covers, hoods, rear wings, center consoles, trim strips, drive shafts, leaf springs, frames, brake pads, interior and exterior accessories. Modified plastics can be mainly used in exterior decorative parts, interior decorative parts, functional parts, and structural parts. However, three are still many drawbacks of application of new energy materials in new-energy vehicle. The current new energy materials used in automotive lightweight technology are usually costly and time-consuming. Moreover, the characteristics of the new energy materials are still not clear. It could have a negative impact on the environment. Before this technology can be widely used in new-energy vehicles, more research is needed regarding the new energy materials.

Developed an Innovative Handbike Fork Made of Composite Material.

In this research, the design of a new competitive handbike fork, made of a composite material, is presented. The study is based both on an early finite element analysis and on a CFD analysis of the characteristics and performance of a standard fork made of aluminum, allowing to define the loading and the flux conditions and to provide a design optimization of the fork. The model was later implemented iteratively with the properties of a carbon-fiber composite material. The results obtained show that the new model allows a weight and a drag force reduction and a downforce improvement, with a stiffness and a safety coefficient comparable to the standard aluminum fork.

Evaluation of CFRP Composite Laminates by Drilling Using Finite Element Approach

Numerical modelling of material behavior & defect formation during machining was made possible by the years. Rapid expansion of the usage of carbon fiber composite materials, which are extensively employed in a variety of civilian industries, including aviation, aerospace, defense, automotive, electronic information, and high-speed machinery. Drilling is a vital final machining process for components made of composite laminates. Determining static structural, dynamic, or vibrational, and explicit dynamics is a crucial challenge in drilling CFRP. In this work, the drilling behavior of CFRP composite laminate with five layers is analyzed. Drilling behavior is examined using the finite element method while taking into account the precise geometrical considerations as well as the static, dynamic, and explicit factors involved in the operation in order to find the initial modes and corresponding natural frequency using Ansys workbench 19.2 and Catia V5 software used to modelling required 3d Geometry.

Contribution to the Microstructural Study of a Composite Material Based on Carbon Fibers for Use in Orthopedic Prostheses

The use of a carbon fiber composite material to make external prostheses in the form of a femoral socket was the subject of this laboratory study. According to the prior bibliographical studies, this material adapts well to this type of prosthesis. The objective of this research is to study its microscopic structure, in order to verify the good wetting of the fibers by the resin, the good cohesion and molding by infusion. The morphological study of the facies of the parallelepiped-shaped specimens was carried out after cuts perpendicular to the axis of the fiber strands, parallel according to the width and thickness of the specimen. This study was carried out using a scanning electron microscope (SEM), in order to determine, thanks to the typical microstructure of the composite, the various degradations, which appear as a result of the effect of static tension. The laminate used is based on three layers of carbon taffeta fabric and an orthocrylic resin. Tensile tests have been carried out at a speed of 1mm/min with a Zwick/Roell machine with a load cell of 50 kN. This speed was chosen to allow a comparative study with glass fiber specimens, which have been used previously for the production of prostheses, before those made of carbon. The microscopic study allowed to identify the four types of degradation; Matrix fracture, which manifested itself as fault lines, in preferred directions of different sizes. This contributed to interlaminar delamination. The decohesion that contributes to delamination in a different way from that of matrix breakage is visible at different levels. Interlaminar delamination results from the combined effect of matrix breakdown and decohesion and manifests itself as uneven strata. Fiber breakage was manifested by shearing. This study allowed to observing a degradation of the material imposed by static traction. As for the material used in orthopaedics, it has retained good cohesion and meets the requirements of prostheses, despite the defects detected by the microscopic study.

Molecular mechanics-based design of high-modulus epoxy to enhance composite compressive properties

The performance of carbon fiber reinforced composites has been shown to be constrained by the low compression to tensile strength ratio, which blocks its lightweight application. Designing and preparing high-strength, high-modulus resins has become a popular direction in the field of synthetic materials and increasing resin modulus has become one of the key goals for improving composite compression properties. This study improves the interactions between molecular segments and reduces chain motility by introducing polar groups into resin molecules and increasing the reactive functionality. Four typical polar epoxy resins with high purity were synthesized, with a modulus of 6500 MPa and a tensile strength of 86 MPa when cured. Hydrogen bonds are detected and the complex process of group changes as a function of temperature is investigated using in-situ IR. The compression properties of the composites made with the newly synthesized resins were significantly improved, which suggests the significance of high-performance resin design in lightweight carbon fiber composite materials.

Design Analysis and Weight Optimization of Mono Leaf Spring by Using ANSYS and Validation with Practical Testing

Abstract: The present paper having a work on Design and analysis of composite leaf spring. The analysis has been conducted by using ANSYS-14.5 workbench software with the help of static structural tool. Two composite leaf springs with full length leave made of E-Glass fiber and Carbon fiber composite material has been used. The results of Conventional steel leaf spring have been compared with the present results obtained for composite leaf spring. Carbon fiber material is better in strength and lighter in weight as compared to the conventional steel leaf spring as well as Glass fiber leaf spring. We worked on different loading condition to validated UTM result with hand calculation and ANSYS result.

Mechanical performance of Continuous/Short carbon Fiber-Reinforced Poly(phenylene sulfide) composites

A method for improving the fracture resistance and mechanical strength behavior of polymer composites by incorporating short carbon fibers into continuous fiber/poly(phenylene sulfide) laminate was explored in this manuscript. This method involves the incorporation of short carbon fibers into continuous carbon fiber thermoplastic laminates, by using the hot compression molding technique. Characterization of a continuous and discontinuous carbon fiber composite material with poly(phenylene sulfide) matrix (S-CCF/PPS laminate) was performed by using tensile, V-Notched Iosipescu, combined load compression and impulse excitation tests. According to the found results for this composite material, it was observed that the tensile strength and the elastic modulus values were 41% and 48% lower than a composite reinforced only by continuous fiber, respectively. The shear strength of the mixed material was found to be 32% lower than a continuous carbon fiber composite. These results were expected since it was used a combination of 50% of continuous and 50% of short carbon fiber, in volume. However, the compression strength of the mixed composite was found to be only 11.9% lower than a laminate reinforced with solely continuous carbon fiber, showing a synergic gain in this case. In addition, the impulse excitation results show that the material mechanical properties are within the expected range, but a high dispersion of the values was observed due probably to the random nature of the discontinuous fiber. Furthermore, it was observed that the failure modes for the composite evaluated in this work are similar to those found for composites processed only with continuous reinforcements and that the models used during the simulations presented similar results to what was found experimentally.