Carbon Fiber Composite Materials Research Articles

Fully aminated p‐polyaramid effectively strengthen and toughen Bisphenol A epoxy resin and its warp‐knitted carbon fiber composites

AbstractStemming from the cost‐effectiveness and broad applicability, many modification researches on Bisphenol A epoxy resin (DGEBA) and its carbon fiber composites have been done extensively. Here, following the concept of molecular composite, we prepared fully aminated p‐polyaramid with reactive amino side groups by polycondensation and reduction reaction, aiming to construct a molecular distribution of the reinforcement within the resin matrix and achieve a satisfactory enhancement effect. Among them, after adding 1 wt% fully aminated p‐polyaramid, Young's modulus and tensile toughness of the DGEBA epoxy resin (EP) increased significantly to 2.34 ± 0.03 GPa (+68.3%) and 4402 ± 213 kJ/m3 (+30.5%), the flexural modulus and toughness reached 4.14 ± 0.04 GPa (+42.8%) and 0.44 ± 0.01 J (+83.3%). Moreover, the Tg of EP was only decreased by 2.7°C. In addition, their warp‐knitted bidirectional carbon fiber composites also have enhancements in both flexural properties and interlaminar shear strength (all improved by more than 20%). What is noticeable is that the preparation and blending of fully aminated p‐polyaramid are simpler and more effective than most other micro‐ or nanofillers, and the dispersion is more uniform. Thus, it can act as a highly effective reinforcement and strengthen the properties of DGEBA and its carbon fiber composite materials significantly.Highlights Fully aminated p‐polyaramid is uniformly dispersed in EP by chemical bonds. DGEBA is strengthened and toughened without a significant decrease in Tg. The tensile and flexural modulus of EP is increased by 68.3% and 42.8%. Fully aminated p‐polyaramid can reinforce warp‐knitted carbon fiber composite.

Energy storaging multifunctional carbon fiber composites based on Nano‐SiO2 reinforced epoxy matrix structural electrolytes

AbstractMultifunctional carbon fiber composite materials capable of storing energy and carrying structural loads have advantages for aerospace structures. In this paper, a structural supercapacitor that consists of an epoxy‐based solid polymer electrolytes (E‐SPEs) and carbon fiber was proposed. To develop an E‐SPEs with better mechanical properties and ionic conductivity, Nano‐SiO2 was introduced into the solid polymer electrolytes. Nano‐SiO2 reinforced E‐SPEs (Nano‐SiO2/E‐SPEs) show improved mechanical properties (Young's modulus [E] = 0.85 GPa) and ionic conductivity (4.99 × 10−4 S cm−1), compared to E‐SPEs without Nano‐SiO2. Structural supercapacitors were further prepared by combining E‐SPEs with carbon fibers. The structural supercapacitor prepared with Nano‐SiO2/E‐SPEs exhibits the higher power and energy density (261.93 W kg−1 and 2.11 Wh kg−1) compared to the structural supercapacitor prepared with E‐SPEs without Nano‐SiO2 (51 W kg−1 and 0.34 Wh kg−1), indicating improved mechanical and energy storage properties for structural supercapacitors after incorporation of Nano‐SiO2. This strategy has great potential in enhancing performance of structural energy storage composite materials for application in next‐generation aerospace vehicles.

Inclination information-aided circumferential deformation reconstruction error correction method for CFRP belt integrated with optical fiber sensor

In view of the problem that the distributed optical fiber-based deformation reconstruction method can produce serious accumulated errors, this paper developed a smart fiber optic sensor belt that employs a carbon-fiber composite material as the matrix and strain-sensing fiber optics as the sensing element and is based on the key-point dip angle information acquired by a high-precision tilt sensor. The method of in situ correction for the cumulative error of circumferential deformation was investigated, and the particle swarm optimization algorithm was adopted to perform in situ correction for the reconstructed circumferential deformation field of the sensor belt to reduce the cumulative measurement error of the circumferential deformation field. Simulations and indoor tests were systematically performed. After the correction, the errors of the simulation and indoor tests were reduced from 210.83 and 235.82 mm to 2.17 and 4.04 mm, respectively, which verified the effectiveness and accuracy of the aforementioned method.

Ultrasonic detection, characterization, and simulation of delamination defects in composite laminates

Composite materials are of great importance in many industries due to their unique properties, strength and durability, but they also include disadvantages that can affect their use and must be studied. In this article, we simulate the acoustic interference field received by a delay line following an interaction between an acoustic field and a multilayer carbon fibre composite material using the ray approach. In this case, the simulation is performed using carbon fiber composite plates, where some plates have lamination defects such as delamination, while others are free of these defects. Experimental measurements are performed on carbon fiber composite plates with and without delamination defects introduced beforehand, without knowing their thickness. The thickness of each ply is 0.125 mm. The transducer used is a focusing immersion transducer type parametric (V 312) that operates at a frequency of 10 MHz The simulation results almost exactly corroborate those of the experiment. The simulation model was employed to determine the thickness of the induced delamination, which is 0.2 mm, found in the second and third layers.

Design optimization of automotive carbon fiber composite material floor laminate based on PSO-BFO algorithm

In response to the current challenges of low precision and efficiency in the optimization of composite material layups, the insufficient lightweight of automotive body floors, and the high cost of carbon fiber composites, this study introduces an optimized design method for carbon fiber composite flooring layups. Based on implicit parametric technology, a hybrid PSO-BFO (Particle Swarm Optimization-Bacterial Foraging Optimization) algorithm is employed. This approach achieves an integrated optimization of materials, processes, and structures, thereby balancing and reducing costs. The SFE-CONCEPT is utilized to establish an implicit parameterization model for the body floor, which is validated through experiments and finite element simulation analysis. Concept design and modeling of the carbon fiber composite material floor laminate are performed. Continuous variable optimization is employed to determine the thickness, tile shape, and number of layers for the front, middle, and rear floors. A continuous variable discretization rounding strategy is used to obtain the discrete layer numbers for each laminate orientation of the composite material floor. The continuous fiber lamination strategy is applied to create different shared lamination regions. The PSO-BFO hybrid optimization method is proposed to optimize the lamination sequence as a multi-objective optimization, addressing the challenges of discrete lamination sequence, explosive combinations, and multiple variables in the optimization design of carbon fiber composite material floor laminates. The optimization results demonstrate improvements of 34.4% in floor quality M, 6.0% in static bending stiffness BS, and 5.3% in lightweight coefficient QLX using the proposed PSO-BFO method. PSO-BFO and PSO-GA (Particle Swarm Optimization-Genetic Algorithm) methods are more capable of obtaining global optimal solutions for complex optimization problems than single optimization algorithms. Still, the results obtained by the PSO-BFO method are more balanced.

Research on composite material riveting simulation method for engineering applications

PurposeIn order to improve the efficiency and reliability of simulation analysis for composite riveting structures in engineering products, a comparative study was conducted on different forms of riveting simulation methods.Design/methodology/approachFive different rivent simulation models were established using the finite element method, including rigid element CE, flexible element Rbe3 and beam element, and their results were future compared and analyzed.FindingsUnder the given technical parameters, the simulation method of Rbe3 (with holes) + beam can meet the analysis requirements of complex engineering products in terms of the rationality of rivet load distribution, calculation error and relatively efficient modeling.Originality/valueThis study proposes a simulation method for the riveting structure of carbon fiber composite materials for engineering applications. This method can satisfy the simulation analysis requirements of transportation vehicles in terms of modeling time, computational efficiency and accuracy. The research can provide technical support for the riveting process and mechanical analysis between carbon fiber composite components in transportation products.

Effect of Cutting Conditions on the Size of Dust Particles Generated during Milling of Carbon Fibre-Reinforced Composite Materials.

Conventional dry machining (without process media) of carbon fibre composite materials (CFRP) produces tiny chips/dust particles that float in the air and cause health hazards to the machining operator. The present study investigates the effect of cutting conditions (cutting speed, feed per tooth and depth of cut) during CFRP milling on the size, shape and amount of harmful dust particles. For the present study, one type of cutting tool (CVD diamond-coated carbide) was used directly for machining CFRP. The analysis of harmful dust particles was carried out on a Tescan Mira 3 (Tescan, Brno, Czech Republic) scanning electron microscope and a Keyence VK-X 1000 (Keyence, Itasca, IL, USA) confocal microscope. The results show that with the combination of higher feed per tooth (mm) and lower cutting speed, for specific CFRP materials, the size and shape of harmful dust particles is reduced. Particles ranging in size from 2.2 to 99 μm were deposited on the filters. Smaller particles were retained on the tool body (1.7 to 40 μm). Similar particle sizes were deposited on the machine and in the work area.

Research on defect identification of carbon fiber composite materials based on ultrasonic phased array

AbstractIt is more and more difficult to identify defects in carbon fiber composite materials due to the difficulty in making defect samples and the single signal analysis method. In order to better solve the problem of defect identification in carbon fiber composite materials, this study uses ultrasonic phased array equipment to quantitatively locate and detect carbon fiber composite laminates with embedded delamination defects, so as to more intuitively and effectively display the appearance of different delamination defects. The time domain analysis of the collected ultrasonic original signal and the time‐frequency domain analysis using wavelet packet are carried out. A total of 6 eigenvalues were extracted to reflect the ultrasonic signals of different delamination defects. By using genetic algorithm to optimize BP neural network, the recognition accuracy of delamination defects of different sizes is more than 95%, and the recognition accuracy of delamination defects of different depths is 100%, so as to realize the effective intelligent recognition of delamination defects of different sizes and depths of carbon fiber composites. This study is of great significance to improve the accuracy and reliability of defect identification of carbon fiber composite materials.Highlights The ultrasonic phased array equipment is used to quantitatively locate the carbon fiber composite laminates with embedded delamination defects, so that the appearance of different defects can be displayed more intuitively and effectively. Using time domain analysis and time‐frequency domain analysis based on wavelet packet, the combination of the two can more comprehensively extract the effective features of the defect signal. The BP neural network is optimized by genetic algorithm, and the results can effectively and automatically identify different layered defects, which lays a good foundation for the rapid and accurate identification of more defects in the future.

Rigid-flexible coupling dynamic modelling and dynamic accuracy analysis of planar cam four-bar mechanism with multiple clearance joints

Combination mechanism of conjugate cam and four-bar is a complex type of multi-body system, in which the coupling problems such as cam profile law, flexible deformation of connecting rods, and multiple joint clearance collision make it difficult to model and optimise its dynamics. Just as the beating-up mechanism of high-speed rapier looms for multi-layer weaving is a representative conjugate cam four-bar mechanism. In response to the current development of textile machinery in the direction of high-speed and precision, and in order to improve the work efficiency and operational accuracy of the conjugate cam four-bar beating-up mechanism, the following work is done for the purpose of taking into account the multi-joint clearance and the flexible rod based on the mechanism. Firstly, based on Kane's equation, a multi-body dynamic model with multiple clearances is established combined with clearance collision theory. Secondly, a dynamic model of a rigid-flexible coupling system with multiple revolute clearances is established using finite element method combined with modal synthesis technology. Subsequently, the variables separation method and mode superposition method are used to solve the dynamic equations of the coupled system. Finally, numerical examples are used to analyse the effects of clearance quantity, clearance size, mode truncation order, cam speed, and component material properties on the dynamic response and accuracy of the system. The results show that, in the rotational speed range of 600–800 rpm, the dynamic performance of the system is little affected by the speed; Through comparative analysis of multiple materials, it is found that selecting carbon fibre composite materials has the smallest impact on the motion accuracy of the system. In this paper, the clearance collision model, finite element model and rigid-flexible coupling dynamic model are integrated, which are applied to the cam-linkage combined multi-body mechanism, and the dynamic problems of the actual machine are analysed and solved.

Mechanical performance simulation and optimal design of carbon fiber composite B-pillar

This study primarily concentrates on the layer optimization and structural refinement of carbon fiber composite B-pillars. In the initial phase, an initial layer configuration for the carbon fiber composite material B-pillar was devised, followed by comprehensive finite element numerical simulations. The weight of the B-pillar was effectively diminished by 44.9% compared to its metal counterpart, while maintaining consistent performance across diverse operational conditions. Subsequently, an advanced layer thickness optimization model was formulated, incorporating the innovative ‘super layer’ concept. Integration of simulation software, such as ISIGHT and ABAQUS, facilitated the determination of optimal layer thickness and ratio for the composite material. The layer order was systematically optimized through the application of a discrete particle swarm optimization algorithm based on exchange order, adeptly addressing issues related to discontinuous design variables and potential combinations. The incorporation of a ply drop-off structure laying scheme was derived, resulting in an impressive weight reduction of 57.5%. In the final phase, adherence to NCAP side collision testing standards enabled a comprehensive evaluation, where in various indicators including deformation mode, intrusion amount, and intrusion speed were employed. The results substantiate that the composite B-pillar exhibits equivalent side impact resistance to the original metal B-pillar, ensuring robust passenger protection.

Preparation of superhydrophobic carbon fiber composite surface with excellent durability

AbstractSuper‐hydrophobic surface has excellent waterproof, self‐cleaning and delayed icing properties, and is widely used in various fields, but its lack of durability restricts its large‐scale use. In this paper, carbon fiber composite material with excellent mechanical properties is selected as the substrate, PTFE nanoparticles with excellent hydrophobicity are used as the surface energy substance, and metal screen is selected as the template, combined with hot pressing molding process, a super‐hydrophobic surface with multi‐level micro‐nano structure is successfully constructed. The test shows that the water contact angle of the surface is 169°, and the rolling angle is about 2°. The contact angle of the surface is also over 150° for other liquids, and it bounces off the external water droplets for three times, so it can easily take away pollutants and keep the surface dry and clean under the action of water flow. In the same icing environment, compared with the original surface, it can prolong the freezing time of droplets by 5 times. After repeated rubbing, the surface still has superhydrophobic properties until the whole surface is completely destroyed. The preparation method used in this study is simple, and the prepared superhydrophobic surface has excellent performance, which is expected to promote the application of superhydrophobic surface in practical working conditions.Highlights The preparation method is fast, efficient, low‐energy and environment‐friendly, and the used materials are simple and economical, and can be reused. The prepared surface has excellent hydrophobic performance for different media. The prepared superhydrophobic surface has low adhesion and droplet rebound performance. The prepared superhydrophobic surface has excellent delayed icing performance. The prepared superhydrophobic surface has excellent wear resistance.

Domain Decomposition and Model Order Reduction for Electromagnetic Field Simulations in Carbon Fiber Composite Materials

The computation of the electric field in composite materials at the microscopic scale results in an immense number of degrees of freedom. Consequently, this often leads to prohibitively long computation times and extensive memory requirements, making direct computation impractical. In this study, one employs an innovative approach that integrates domain decomposition and model order reduction to retain local information while significantly reducing computation time. Domain decomposition allows for the division of the computational domain into smaller, more manageable subdomains, enabling parallel processing and reducing the overall complexity of the problem. Model order reduction further enhances this by approximating the solution in a lower-dimensional subspace, thereby minimising the number of unknown variables that need to be computed. Comparative analysis between the results obtained from the reduced model and those from direct resolution demonstrates that our method not only reduces computation time but also maintains accuracy. The new method effectively captures the essential characteristics of the electric field distribution in composite materials, ensuring that the local phenomena are accurately represented. This study provides a contribution to the field of computational electromagnetics by presenting a feasible solution to the challenges posed by the high computational demands of simulating composite materials at the microscopic scale. The proposed methodology offers a promising direction for future research and practical applications, enabling more efficient and accurate simulations of complex material systems.

Comparative analysis of experimental and simulation results of composite circular tube

Abstract In this work, the internal pressure of the composite pipe is analysed and studied when transporting liquid or gas. The quasi-static hydraulic test is designed to simulate the internal pressure of the composite pipe. By using the ABAQUS finite element method, a numerical model of the composite pipe under hydraulic load is established. The strain curves and final failure modes of the test and simulation are compared to verify the feasibility of the finite element method model. Finally, the damage mechanism of the composite tube is analysed according to the numerical model, and it is found that the carbon fibre composite material has an important effect on the bearing capacity of the composite tube.

Simulation and Experimental Study of Mooring Function Composite Fragile Cover

Abstract Under the requirement that the fragile cover does not eject debris during missile launches, and to meet the demands of rapid combat, there is an urgent need for a lightweight missile launching system. Enhancing the effective utilization area of the fragile cover is an effective way to realize the lightweight of the missile launching system. This paper utilizes the properties of carbon fiber composite materials to design a novel frangible cover with mooring functionality and establishes numerical models for the cover’s pressure and bursting dynamics. In the pressure finite element model, the Tasi-Wu failure criterion is employed for damage assessment. In the bursting dynamics finite element model, a cohesive element is used to simulate the elastic behavior and damage evolution of the weak area, while a membrane element is employed to simulate the mooring function. Comparative analysis of numerical results with experimental data reveals minor discrepancies, with errors of 5.44% for maximum deformation under pressure and 8.1% for bursting force, respectively, validating the model’s rationality and effectiveness. Results from both experimental tests and finite element analyses demonstrate the successful implementation of mooring functionality in the segmented body. The effective utilization area of the cover was increased by 71.13%. This research provides a feasible direction for subsequent studies on non-ejecting frangible covers.

Effect of the Atmospheric Plasma Treatment Parameters on the Surface and Mechanical Properties of Carbon Fabric.

The use of Atmospheric Pressure Plasma Jet (APPJ) technology for surface treatment of carbon fabrics is investigated to estimate the increase in the fracture toughness of carbon-fiber composite materials. Nitrogen and a nitrogen-hydrogen gas mixture were used to size the carbon fabrics by preliminarily optimizing the process parameters. The effects of the APPJ on the carbon fabrics were investigated by using optical and chemical characterizations. Optical Emission Spectroscopy, Fourier Transform Infrared-Attenuated Total Reflection, X-ray Photoelectron Spectroscopy and micro-Raman spectroscopy were adopted to assess the effectiveness of ablation and etching effects of the treatment, in terms of grafting of new functional groups and active sites. The treated samples showed an increase in chemical groups grafted onto the surfaces, and a change in carbon structure was influential in the case of chemical interaction with epoxy groups of the epoxy resin adopted. Flexural test, Double Cantilever Beam and End-Notched Flexure tests were then carried out to characterize the composite and evaluate the fracture toughness in Mode I and Mode II, respectively. N2/H2 specimens showed significant increases in GIC and GIIC, compared to the untreated specimens, and slight increases in Pmax at the first crack propagation.

Application of carbon fiber composite materials in aircraft

Carbon fiber composite is a material with excellent mechanical properties. Compared with other high-performance fiber materials, carbon fiber composites have the advantages of high strength and high modulus even at ultra-high temperatures. In addition, the carbon fiber composite material also has excellent electrical and thermal conductivity and electromagnetic shielding performance. Carbon fiber composites are widely used in the aircraft manufacturing industry due to their incomparable performance with other composite materials. In recent years, the amount of carbon fiber composite materials in newly developed aircraft products has reached more than 50%. This paper aims to explore the application of carbon fiber in aircraft, and to reflect the importance of carbon fiber composite materials by comparing models that use composite materials and models that do not use composite materials. The study explores the application of carbon fiber composite materials in aircraft through a comprehensive literature analysis and review. Key findings indicate significant advantages of these materials in enhancing aircraft performance, including reduced weight and increased strength. The paper also discusses the challenges in manufacturing and environmental impacts, offering insights into future research directions for sustainable aviation technologies.

3D printing path method for multi-tow continuous carbon fiber

Carbon fiber composite materials have many excellent characteristics such as high temperature resistance, friction resistance, thermal conductivity and corrosion resistance, so carbon fiber composite materials have become the first choice for printing materials. In order to improve the printing efficiency of carbon fiber 3D printing technology, it has been expanded to four side-by-side nozzles based on traditional single nozzles, and four nozzles are bound to print side by side. The four-nozzle side-by-side printing path has the problem of coordinating the motion planning of each nozzle, controlling the squeezing difference of each nozzle, and adjusting the angle of the print head, so it is necessary to reasonably control the squeezing amount of each nozzle and the angle of the print head. After the slicing processing based on the existing model, the Gcode code of the model is obtained. The Gcode code of the model is processed through the multi-tow continuous carbon fiber 3D printing path planning algorithm. The movement trajectory of each nozzle of the printer is reasonably planned based on the outer wall coordinates and the extrusion amount of each nozzle is controlled. Finally, the snipping instruction is executed after a circle of trajectory to print the next layer of motion trajectory, which ultimately improves the 3D printing while ensuring the accuracy of multi-beam model 3D printing.

5G-enabled, battery-less smart skins for self-monitoring megastructures and digital twin applications.

With the current development of the 5G infrastructure, there presents a unique opportunity for the deployment of battery-less mmWave reflect-array-based sensors. These fully-passive devices benefit from having a larger detectability than alternative battery-less solutions to create self-monitoring megastructures. The presented 'smart' skin sensor uses a Van-Atta array design enabling ubiquitous local strain monitoring for the structural health monitoring of composite materials featuring wide interrogation angles. Proof-of-concept prototypes of these 'smart' skin millimeter-wave identification tags, that can be mounted on or embedded within common materials used in wind turbine blades, present a highly-detectable radar cross-section of - 33.75 dBsm and - 35.00 dBsm for mounted and embedded sensors respectively. Both sensors display a minimum resolution of 202 -strain even at 40 off-axis enabling interrogation of the fully-passive sensor at oblique angles of incidence. When interrogated from a proof-of-concept reader, the fully-passive, sticker-like mmID enables local strain monitoring of both carbon fiber and glass fiber composite materials. The sensors display a repeatable and recoverable response over 0-3000 -strain and a sensitivity of 7.55 kHz/ -strain and 7.92 kHz/ -strain for mounted and embedded sensors, respectively. Thus, the presented 5G-enabled battery-less sensor presents massive potential for the development of ubiquitous Digital Twinning of composite materials in future smart cities architectures.

A study on the strand arrangement in 3D printing of continuous carbon fiber composite materials with multiple strands

3D printing of continuous carbon fiber composite materials with multiple strands has significant potential for improving model forming efficiency. However, in this field, we are faced with the challenge of arranging multiple fiber strands closely without excessive overlap consolidation, to avoid damage to the original model. The inability to effectively control the arrangement of multiple strands can significantly affect the print accuracy and mechanical performance of the model. Therefore, in this study, a predictive formula for the line width of carbon fiber strands is first presented. Subsequently, a device dedicated to 3D printing with multiple strands is designed using this formula, and the interrelationship between pressure and the arrangement of multiple strands is delved into. Comparative tests are also conducted on printed parts for tension and bending to investigate the influence of strand arrangement tightness on the mechanical performance of printed samples under different pressure conditions. Through electron microscopy experiments to analyze the microstructure of fracture surfaces, the causes of differences in mechanical performance and the potential effects of different pressures on print accuracy are explained. The results of the study indicate that when pressure can be precisely controlled to ensure a tight arrangement between multiple strands, the mechanical performance of printed parts reaches its optimal state. The tensile strength can reach 360.62 MPa, and the bending strength is 311.04 MPa. At the same time, for test samples printed under the optimal printing pressure, their surface accuracy is also at its best.

PECT Composite Defect Detection Algorithm Based on DualGAN

To address the problems of insufficient accuracy and slow reconstruction speed of Planar Electrical Capacitance Tomography (PECT) detection of damaged specimens, a Dual Generative Adversarial Networks (DualGAN)-based PECT image defect detection method is proposed in this paper. The improved particle swarm algorithm with adaptive particle number and L2-norm is used to optimize the sensitivity field, combined with the parallel Landweber algorithm to solve the PECT inverse problem to obtain the dielectric constant distribution map. In the DualGAN network, the Unet generator utilizes an Adam-based local attention mechanism to adjust module weights, facilitating feature extraction and the generation of high-quality transformation images of the Landweber dielectric constant distribution. A PatchGAN discriminator is employed to distinguish between transformation images and real images, using the generated transformation images as target images. Experimental results demonstrate that the sensitivity field, enhanced by the improved particle swarm algorithm and L2-norm normalization, achieves better balance. Furthermore, the addition of a network transformation using the Adam-based local attention weight mechanism on the DualGAN network reduces artifacts in the reconstructed images, resulting in more accurate PECT reconstructions. The PECT image defect detection method, integrating DualGAN, an improved particle swarm optimization algorithm, and a local attention mechanism, has made significant strides in addressing challenges related to image reconstruction accuracy and speed. This technological advancement has enhanced the precision and efficiency of defect detection in carbon fiber composite materials, thereby fostering the broader utilization of planar capacitance tomography technology in industrial damage detection and material defect analysis.