Carbon Fiber Composite Research Articles

METODE PENINGKATAN KETAHANAN RETAK RESIN POLYESTER DENGAN PENAMBAHAN PROSENTASE VINYL ESTER

In previous studies, hybrid crash boxes have been developed because it show better energy absorption characteristics. Circular hybrid crash box combine the advantages of low-density of composite with stable deformation of metal provide a potential energy absorption device. Tests were carried out experimentally and iumerically under frontal load. This study aims to determine the energy absorption characteristics of two different configuration of hybrid material compositions using Aluminum Alloy 6063 and T300-epoxy Carbon Fiber composites. Present two typical configurational schemes, namely Al-Ko (i.e. a metal outer tube internally filled with an inner carbon fiber reinforced plastic (CFRP) tube) and Ko-Al (i.e. an outer composite tube internally filled with an inner metal tube). Composite layups arrangement with fiber orientation direction [0,90]10. First, the simulation models were developed and validated by comparing the damage modes and crashworthiness indictors with the dedicated experimental study. Second, the interactive effects of different configuration hybrid tubes were investigated by analyzing the discrepancies in the deformation pattern and internal energy absorption of each material through the validated simulation models. The test results show that the greatest energy absorption occurs in the Al-Ko model of 7401.4 J. This hybrid crash box has an energy absorption value of 11% greater compared to the sum of the energy absorption of aluminum tubes (3746.5 J) and composite tubes (2923.4 J).

Local elasticity assessment of unidirectional fiber-reinforced polymer composites through impulse excitation and machine learning

This study presents a novel methodology that integrates the Impulse Excitation Technique (IET) and machine learning (ML) to predict local elastic properties within isolated regions of unidirectional polymeric composite plates. The proposed model incorporates fiber volume and plate thickness as input parameters and leverages the first resonance frequencies of the local region at different fiber orientations, thus accounting for the composite’s anisotropy. Regression results from the deep neural network (DNN) model demonstrate robust prediction performance across all output targets in both testing and training datasets, with R2 coefficients surpassing 0.9. The model exhibits particularly strong performance in predicting Young’s moduli. Additionally, each output objective shows sensitivity to a unique balance of input parameter weight factors for achieving optimal ML predictions. Moreover, a parabolic trend in the weight factors of fundamental frequencies at different orientations is observed as the rigidity of composites changes. Lastly, a comparative study between carbon-fiber and glass-fiber composites highlights the variations in fiber volume and elastic constants, emphasizing the effectiveness of the proposed model in accurately predicting material properties.

On the Hydrodynamic and Structural Performance of Thermoplastic Composite Ship Propellers Produced by Additive Manufacturing Method

In the marine industry, the search for sustainable methods, materials, and processes, from the product’s design to its end-of-life stages, is a necessity for combating the negative consequences of climate change. In this context, the lightening of products is essential in reducing their environmental impact throughout their life. In addition to lightening through design, lightweight materials, especially plastic-based composites, will need to be used in new and creative ways. The material extrusion technique, one of the additive manufacturing methods, is becoming more widespread day by day, especially in the production of objects with complex forms. This prevalence has not yet been reflected in the marine industry. In this study, the performances of plastic composite propellers produced by the material extrusion technique is investigated and discussed comparatively with the help of both hydrodynamic and structural tests carried out in a cavitation tunnel and mechanical laboratory. The cavitation tunnel test and numerical simulations were conducted at a range of advance coefficients (J) from 0.3 to 0.9. The shaft rate was kept at 16 rps. The thrust and torque data were obtained using the tunnel dynamometer. Digital pictures were taken to obtain structural deformation and cavitation dynamics. The structural performance of the propellers shows that an aluminum propeller is the most rigid, while a short carbon fiber composite propeller is the most flexible. Continuous carbon fiber composite has high strength and stiffness, while continuous glass fiber composite is more cost-effective. In terms of the hydrodynamic performance of the propellers, flexibility reduces the loading on the blade, which can result in thrust and torque reduction. Overall, the efficiency of the composite propellers was similar and less than that of the rigid aluminum propeller. In terms of weight, the composite carbon propeller containing continuous fiber, which is half the weight of the metal propeller, is considered as an alternative to metal in production. These propellers were produced from a unique composite consisting of polyamide, one of the thermoplastics that is a sustainable composite material,, and glass and carbon fiber as reinforcements. The findings showed that the manufacturing method and the new composites can be highly successful for producing ship components.

Analysis of Factors Influencing the Reaction Intensity of Composite Propellants with Different Casing Materials under Slow Cook-off

Abstract By conducting slow cook-off tests on solid composite propellants, the combustion response characteristics of propellants under different casing materials were investigated. Propellant slow cook-off combustion experiments were designed and carried out. Combining the morphological changes of propellant thermal decomposition weight loss with theories of material mechanics and heat transfer, the heat transfer process and physical state of the propellant before ignition were examined to explore their effects on after ignition reaction intensity. The results indicated that the reaction intensity varied with different casing materials. When the casing material is 45# steel, spontaneous ignition occurred at 214.88, with a slider speed of 14.83 m/s, classifying the reaction as deflagration. For 2A12 aluminum casing material, spontaneous ignition occurred at 199.13, with a slider speed of 0.71 m/s, classifying the reaction as combustion. When the casing material is carbon fiber composite, the reaction was classified as combustion. Different casing materials influence the reaction intensity through their thermal physical parameters and casing constraint strength, providing guidance for the selection and design of casing materials and constraints in slow cook-off combustion of motors.

Characterization of modified resin-based carbon fiber composite

Abstract This paper investigated the improvement of toughness and mechanical properties in resin castings. The results suggested that the resin system met the film-forming requirements for hot-melt film immersion technology when the toughening agent was added at a content of 6 parts. The resin casting demonstrated a substantial enhancement in impact toughness while maintaining its heat resistance. The impact strength was elevated by 48%, and there was a concurrent increase in bending strength of over 4%. Based on the results of resin system, the mechanical performance of type I, II and III carbon fiber composites was investigated. Finally, the interface of composite was analysed. The results indicated that the mechanical performance of type I composite was comparable to that of type III. The tensile strength of type I was 2761 MPa, with a modulus of 176 GPa. The bending strength measured at 2189 MPa, with a modulus of 162 GPa. Additionally, the shear strength was recorded at 98 MPa, while the impact toughness reached 282 kJ/m2. Furthermore, the compressive strength was determined to be 1.03 GPa. It was worth noting that the carbon fiber exhibited excellent bonding performance with the resin following the mechanical properties test.

Carbon Nanotubes and Nanofibers – reinforcement to Carbon Fiber Composites - Synthesis, Characterizations and Applications: A Review

Carbon Nanotubes and Nanofibers – reinforcement to Carbon Fiber Composites - Synthesis, Characterizations and Applications: A Review

Research Progress on Fatigue of Carbon Fiber Composite Materials and Their Bolted Connection Structures

This paper primarily investigates the fatigue performance of carbon fiber composites and their bolted joint structures. Carbon fiber composites have gained increasing attention due to their high strength, lightweight properties, and corrosion resistance. However, technical challenges remain regarding the fatigue characteristics of carbon fiber composites and the durability of their joint structures in practical applications. This paper reviews the research progress on fatigue performance testing of carbon fiber composites at home and abroad, focusing on failure mechanisms under cyclic loading, fatigue life prediction methods, and key influencing factors. Additionally, the paper discusses the current research status of bolted joint structures in carbon fiber composites, analyzing the impact of different joint methods on structural fatigue performance, as well as existing experimental and simulation research methods.

Ultrasonic detection and evaluation of delamination defects in carbon fiber composites based on finite element simulation

Delamination defects are prone to occur during the production and use of carbon fiber composites, which seriously affect the mechanical properties of the material. The production cost of carbon fiber composites is high, and it is difficult to create defect samples. In light of this, a method for ultrasonic testing of delamination defects in carbon fiber composites based on finite element simulation was studied, and the test results were evaluated accordingly. First, a finite element model of the carbon fiber composite material was established using COMSOL software, and ultrasonic testing was employed to detect delamination defects of varying sizes and positions. Next, ultrasonic detection signals and sound field cloud images were obtained through simulation. Finally, quantitative positioning detection was conducted by fabricating laminated carbon fiber composite samples with embedded delamination defects. The results indicate that the finite element model accurately reflects the sound field propagation of ultrasonic waves. The simulated and experimental waveform signals show high consistency in both amplitude and time-domain positioning, with an error margin within 3%. The simulation model exhibits good reliability. This study provides a time-saving, labor-saving, and cost-effective approach for the detection and analysis of defects in carbon fiber composites.

The Influence of Matrix Resin Toughening on the Compressive Properties of Carbon Fiber Composites.

The study investigated the effects of a toughening agent and micron-sized toughening particles (TP) on the resin and carbon fiber-reinforced polymer (CFRP) composites, with a particular focus on compressive strength. The results showed that the addition of the toughening agent improved the overall mechanical properties of both the resin and CFRP but had a minor effect on the residual compressive strength (CAI) of CFRP after impact. Compared to the pure toughening agent, the addition of TP increased the CAI, GIC, and GIIC of CFRP by 74%, 35%, and 68%, respectively. The SEM, ultrasonic C-scan, and metallographic microscopy were used to analyze the failure morphology and TP distribution. Compared to pure toughening agent modification, the introduction of TP led to the formation of continuous toughening particle layers, which reduced the compression damage area by 61%, significantly balancing and absorbing the load. This modification also resulted in typical kink band damage. This study found that resin toughening significantly improved the compressive strength of CFRP, while micron-sized toughening particles, in the form of toughening layers, notably improved the CAI. These findings provide valuable insights for enhancing the compression and impact resistance of CFRP.

Characterization of Direct Ink Writing carbon fiber composite structures with serial sectioning and DREAM.3D

Direct Ink Writing (DIW) combines the flexibility of 3D printing with increased material applications such as thermoset carbon fiber composites, ceramic composites, and metals. The usefulness of direct ink writing, like many additive manufacturing (AM) processes, remains limited for reasons ranging from quality control to lack of process parameter optimization. This study looks to introduce a methodology for characterizing direct ink written carbon fiber composites to facilitate exploration into the relationships between process parameters and material structure. The presented study utilized nine 3D specimens of direct ink writing carbon fiber composites printed with varying process parameters – speed differential, layer height, step-over distance, and nozzle diameter – as the data set. The data was collected with an automatic serial sectioning system, LEROY, from the Air Force Research Laboratory. The collected data was processed in DREAM.3D and analyzed with statistical comparisons of 2D orientation distributions of the fibers, 2D size distributions of the voids, and 2D shape distributions of the voids.

Thermal transformations during thermal recovery of end-of-life composite carbon fiber beams from wind turbine blades

The effects of thermal recovery technology on the composite carbon fiber beams from wind turbine blades were investigated. Nonisothermal thermogravimetric experiments performed under different atmospheres showed that the reaction activation energy were the smallest for N2, and Δm was approximately 21.64 %. The activation energy was largest in air. The activation energies of the nonisothermal reactions at heating rates of 5, 10, and 15 °C/min in N2 were 93.43, 116.95 and 128.86 kJ/mol, respectively. Higher heating rates led to more difficult reactions. The compositions of the products formed during isothermal pyrolysis at 600 °C were analyzed. CO2 was the main component of gaseous products; and the remaining components were small combustible gases. The gas products accounted for 4.58 % of the total yield. The liquid tar product was approximately 21.28 %, featuring mostly aromatic substances containing arene rings, similar to phenol. The solid products accounted for approximately 74.14 % of the weight of the original reactant. The reaction mechanism was analyzed; the reaction predominantly involved the resin component of the composite, and the recovered carbon fibers remained essentially unchanged after the reaction. These results showed that it is feasible to recover carbon fibers from wind turbine blade composite carbon fiber beams by pyrolysis.

Investigation of two sandwich-structured nanohybrid coating derived from graphene oxide/carbon nanotube on interfacial adhesion and fracture toughness of carbon fiber composites

Designing stronger interphase towards solving the long-standing dilemma of interfacial delamination is critical for stable application of carbon fiber composites. Herein, nano-scale sandwich-structured coatings, where carbon nanotubes (CNTs) were uniformly anchored on both sides of graphene oxide (GO) layer (abbreviated as C/GO/C) and its reverse, that is double GO layers encapsulated CNT network (G/CNT/G in short), were reported around fiber periphery via vacuum filtration method. The effects of surface structure differences on interfacial shear strength (IFSS) and fracture toughness were compared in epoxy matrix. Impressively, composite incorporating G/CNT/G modified fiber delivered prominent IFSS and interfacial fracture toughness of 114.6 MPa and 137.0 J/m2, 105.7 % and 279.5 % increases over control fiber composite. This strategy was also superior to C/GO/C and other reported GO and CNT related works. The main factors for maximal IFSS offered by G/CNT/G are that two GO panels enrich active sites to tightly bridge fiber and epoxy, as well as its layered feature and large surface area provide a stable “skeleton” at interphase for stress transfer. Additionally, the G/CNT/G “skeleton” is closer to sandwich structure of iris leaf, in which the porous CNT intermediate network creates larger deformation and adsorb more energy, leading to peak interfacial fracture toughness.

THz Polarimetric Imaging of Carbon Fiber-Reinforced Composites Using the Portable Handled Spectral Reflection (PHASR) Scanner.

Recent advancements in novel fiber-coupled and portable terahertz (THz) spectroscopic imaging technology have accelerated applications in nondestructive testing (NDT). Although the polarization information of THz waves can play a critical role in material characterization, there are few demonstrations of polarization-resolved THz imaging as an NDT modality due to the deficiency of such polarimetric imaging devices. In this paper, we have inspected industrial carbon fiber composites using a portable and handheld imaging scanner in which the THz polarizations of two orthogonal channels are simultaneously captured by two photoconductive antennas. We observed significant polarimetric differences between the two-channel images of the same sample and the resulting THz Stokes vectors, which are attributed to the anisotropic conductivity of carbon fiber composites. Using both polarimetric channels, we can visualize the superficial and underlying interfaces of the first laminate. These results pave the way for the future applications of THz polarimetry to the assessment of coatings or surface quality on carbon fiber-reinforced substrates.

(Invited) Atmospheric Corrosion of Multi-Materials on Winter Road Condition in Cold Region

The use of multi-materials such as composites of carbon fiber reinforced thermoplastic (CFRTP) and high-strength steel or CFRTP and aluminum alloy is one of the main strategies for weight reduction in automotive body. When multi-materials are used outdoors, however, they are subject to galvanic corrosion, which increases the risk of failure and shortens their service life. On winter roads in cold regions, automotive bodies suffer significant corrosion due to the large amount of salt particles sprayed as an anti-freeze agent. If the corrosion products of the multi-material are relatively protective, the progression of corrosion can be prevented. Therefore, wet-and-dry cycle test was conducted on a coated multi-material joint consisting of CFRTP/high-strength steel or CFRTP/aluminum alloy plates to simulate winter road conditions in Northern Europe, and corrosion products formed in the crevice of multi-materials joint were investigated using a membrane potential measurement as well as Raman spectroscopy and X-ray fluorescence microscopy.The wet-and-dry cycle test, in which a sample was immersed in a 5:1 mixture of NaCl and CaCl2 solutions for 0.25 h and then repeatedly subjected to a wet atmosphere of 90%RH, 283 K for 4 h and a dry atmosphere of 10%RH, 308 K for 4 h more than a dozen times, was performed according to Kozaki [1]. After several weeks or more of exposure under the wet-and-dry cycle test conditions, corrosion products filled the crevice of the multi-material sample and did not to allow air leakage through the crevice gap. Ion selectivity of the corrosion products in the crevice obtained by the membrane potential measurement was found to be anionic rather than cationic selective in all tests. The products formed in the test using dilute mixture solution were relatively porous hydroxides and oxides and showed larger fixed charge concentrations than those formed in the test using concentrated solution. It was suggested that the density and composition of corrosion products play important roles in preventing atmospheric, galvanic corrosion in the gap of CFRTP/high-strength steel or CFRTP/aluminum alloy joints.[1] T. Kozaki, M. Umeta, J. Surf. Finish. Soc. Jpn. 73 (2022) 384-389.

Mesoscopic Simulation on Centrifugal Melt Electrospinning of Polyetherimide and Polyarylethernitrile

Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains challenging. This research aims to simulate the preparation of high–performance ultrafine PEI or PEN fibers using electrospinning. A mesoscopic simulation model for centrifugal melt electrospinning was constructed to compare and analyze the changes in molecular chain orientation, unfolding, fiber diameter, and fiber yield under high-voltage electrostatic fields. The simulation results showed that temperature and electric field force had a particular impact on the diameter and yield of PEI and PEN fibers. Changes in rotational speed had negligible effects on both PEI and PEN fibers. Additionally, due to their different molecular structures, PEI and PEN, which have different chain lengths, exhibit varied spinning trends. This study established a mesoscopic dynamic foundation for producing high-performance ultrafine fibers and provided theoretical guidance for future electrospinning experiments.

Evaluating the impact of post-processing on the wear and friction properties of polyamide 6 carbon fiber composites produced by fused deposition modeling

The current research addresses the challenges encountered in polyamide 6 carbon fiber composites synthesized by fused deposition modeling. It specifically investigates issues such as inadequate interlaminar bonding and increased void content compared to conventionally manufactured composite components and as-built printed parts. The study focuses on printing pin samples via fused deposition modeling and explores various thermal post-processing methods to reduce void content while preserving dimensional accuracy. To evaluate wear and friction behavior, a pin-on-disc tester was used to test both as-built samples and samples post-heat-treated at 70 °C, 140 °C, and 210 °C. The results indicate that as the applied load increases from 5 to 20 N, both wear rates and friction coefficients increase across all speeds (1–5 m/s). Heating the samples to 70 °C and 140 °C strengthens the interlayer bonding. This significantly improves the maximum wear rates and friction coefficients compared to the as-built samples. However, samples heated to 210 °C do not show much of a change in wear rates or friction coefficients. Samples heated to 210 °C exhibit a decrease in wear rate of 16.87%, 15.82%, and 15.73% for loads ranging from 5 to 20 N, at speeds of 1, 3, and 5 m/s, respectively. This is likely due to pores sealing off and structures binding tightly. The worn surfaces were analyzed using a scanning electron microscope and measured the Shore D hardness of the samples before and after wear testing and documented the results for further analysis. In a scanning electron microscope, samples treated at 210 °C displayed smoother, less worn surfaces. Shore D hardness tests revealed a slightly higher hardness in samples heated to higher temperatures, followed by higher loads and sliding speeds in tribometer tests. This showed that the material was more stable. These post-processing methods significantly advance the development of functional composite elements for superior structural or dynamic performance.

Construction and performance study of interface layer of carbon fiber/epoxy composites by electrostatic adsorption

AbstractElectrostatic adsorption was used to self‐assemble layers of polymers and nanoparticles with varying charges onto the carbon fiber (CF) surface. This process created two distinct ionic crosslinked network layers: (3‐aminopropyl) triethoxysilane‐phytic acid‐polyethyleneimine (APTES‐PA‐PEI) and (3‐aminopropyl) triethoxysilane‐phytic acid‐nano‐silica (APTES‐PA‐SiO2). Fourier transform infrared spectrophotometer (FTIR) and X‐ray photoelectron spectroscopy (XPS) were used to confirm the presence of ionic interactions. The modified carbon fibers (CFs) exhibited increased surface roughness, higher concentration of functional groups, and improved wettability. Compared to untreated CF composites, the interfacial shear strength (IFSS) and the transverse tensile strength test (TFBT) of CF‐APTES‐PA‐PEI/epoxy composites increased by 67.8% and 62%, respectively. In contrast, the IFSS and TFBT of CF‐APTES‐PA‐SiO2/epoxy composites increased by 63.3% and 52.8%, respectively. The observed strengthening is attributed to the combined effects of ionic crosslinked networks, covalent and hydrogen bonding interactions, enhanced wettability, and the relatively roughened fiber surface. The interfacial layer design approach proposed in this study is both straightforward and effective, demonstrating significant potential for functionalizing CFs. This method is expected to be adaptable for other high‐performance fibers.Highlights The ionic cross‐linked network interface layers were designed. IFSS and TFBT were significantly improved. The enhancement mechanism was elaborated.

Damage detection analysis of 3D braided carbon fiber composites with electro-mechanical behavior

The real-time detection of damage is critical for ensuring the safe application of 3D braided carbon fiber composites (3DBCFC) in both aviation and civilian sectors. In this study, we conducted an electro-mechanical behavior analysis of 3DBCFC using data processing tools to quantify various types of damage. The electro-mechanical behavior data were experimentally measured under tensile conditions. The damage detection capability of different electrical current injection methods was also experimentally validated. A mesoscale finite element model was utilized to investigate the damage mechanism of 3DBCFC under tension. Data processing tools, such as principal component analysis (PCA) and k-means clustering (k-MC), were employed to quantify the different types of damage. The study revealed that oblique current injection provided more comprehensive electrical information, making it more effective for damage detection. The electrical signals obtained through oblique current injection could be processed using data tools to quantify damage in 3DBCFC.

Establishing interphase with “rigid-flexible coupling” crosslinked network by supramolecular structure to improve interfacial properties of high-modulus carbon fiber composites

Interfacial properties are a key factor influencing the overall performance of carbon fiber reinforced polymer composites (CFRPs). A novel interphase with “rigid-flexible coupling” crosslinked network is established by introducing supramolecule pseudopolyrotaxane (PPR) on the high modulus carbon fiber (HMCF) surface to improve interfacial properties of CFRPs. Our design utilizes the unique molecular necklace structure of PPR composed of β-cyclodextrin (β-CD) and polyetheramine (PEA). Here, hydroxyl-rich β-CD acts as crosslinking sites and catalyst to enhance interfacial crosslinking density and the mobile main chain PEA serves as an internal stress relaxant to dissipate stress, thereby simultaneously improving the stiffness and toughness of the interphase. The resultant CFRPs exhibit excellent interfacial properties with a 90 % rise in interfacial shear strength (IFSS) and 156 % enhancement in transverse fiber bundle test (TFBT) strength in comparison with desized HMCF composites. This work provides a new strategy for preparing carbon fiber reinforced polymer composites with excellent interfacial properties.

On exploiting the architecture of annual ring growth for developing a new class of bio-inspired composites

Inspired by several biological structures available in nature, bio-inspired composite structures are evidenced to exhibit a noteworthy enhancement in various mechanical and multi-physical performances as compared to conventional structures. This article proposes to exploit the architecture of annual ring growth of the stems of trees for developing a new class of bio-inspired composites with enhanced static and dynamic performances, including deflections, stresses, strain energy, and vibration. Concentric circular annual-ring geometries are considered where each layer of concentric circular fibers is analogous to the growth per annum of trees. The annual rings are modeled in a finite element-based computational framework by idealizing each layer as a composite of graphite fibers and epoxy matrix under different boundary conditions. The ratio of deflection to weight and frequency to weight of bio-inspired and traditional composites are compared by considering different parameters such as the number of annual rings, layers, and supporting stiffeners. The numerical results reveal that the proposed bio-inspired composites can enhance and modulate the static and dynamic properties to a significant extent, opening new design pathways for developing high-performance fiber network composites.