Browse Topic: Carbon fibers

Items (513)
Carbon Fiber Reinforced Polymer (CFRP), as an advanced lightweight structural material, exhibits significant application potential in the protection of electronic devices under extreme vehicle-mounted conditions due to its excellent specific strength and specific stiffness, superior energy absorption capacity, and unique damping and vibration reduction properties. This study closely integrates the characteristics of the complex and variable service environment in vehicles and adheres to the principle of equivalent stiffness matching to conduct innovative design explorations for electronic enclosures made of CFRP. To comprehensively evaluate the dynamic strength performance of CFRP vehicle-mounted enclosures under vibration and impact conditions, in-depth and detailed analyses were conducted using ANSYS software to simulate the power spectral density curves of random vibrations and the loading of post-peak sawtooth waveforms. The results indicate that the carbon fiber enclosure not only achieves remarkable weight reduction but also fully meets the requirements of environmental adaptability standards for automotive equipment. This achievement provides theoretical support and technical guidance for the engineering application of CFRP in the field of vehicle-mounted electronic devices and holds significant engineering application value for promoting the lightweight development of transportation equipment.
Zhang, ShuhuiMa, Qihua
Due to their high specific modulus and specific strength, carbon fiber reinforced polymer (CFRP) composites have been widely adopted in the aviation field. However, CFRP components produced by conventional vacuum assisted resin transfer molding (VARTM) often exhibit defects such as Pores and dry spots. To address these limitations, this study develops a large-area, highly uniform vibration-assisted VARTM (UAVR) system and conducts ultrasound-assisted experiments. The results demonstrate that ultrasonic treatment at various frequencies consistently improves moulding uniformity. In particular, when the ultrasound frequency is 22 kHz, the tensile strength increases by up to 13.23%, and the compressive strength increases by up to 8.48%. This study has practical significance for improving the performance of CFRP.
Fang, KaifaSun, RuqianSong, GaokeZhang, ShuoCheng, LiqiangMa, LipingRuan, BenshuaiXie1, Jiaqing
Test results of the composite helicopter horizontal central-wing under symmetric and unsymmetric loads showed that the strain value of the lower skin would turn from negative to positive, showing a nonlinear behavior. FEM results of the linear and nonlinear analytical approach showed a great difference. The strain value of the lower skin remains negative and decreases linearly when using a linear FEM analysis. The strain value of the lower skin would turn from negative to positive when a nonlinear FEM analysis is applied, and this result agrees well with the test results. Besides, the results of the FEM buckling analysis showed that the buckling load of the lower skin is considerably higher than the value at which the skin would show a nonlinear behavior. Therefore, the specific behavior is a result of the nonlinear property of the structure, not buckling.
Wang, ZheZhang, TiesongLi, MengjiaChen, PuhuiHuang, ZhiwenWang, Binwen
The intent of this specification is for the procurement of carbon fiber and fiberglass epoxy prepreg products with 350 °F (177 °C) cure for aerospace applications; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the production quality assurance section (see 4.3) of this base specification, AMS6891.
AMS P17 Polymer Matrix Composites Committee
This Purchasing Specification (PS), AMS3970/3, specifies the batch release and delivery requirements for carbon fiber fabric epoxy prepreg used for repair. This specification is applicable only when the carbon fiber fabric epoxy prepreg is used as part of the repair system defined in AMS3970 and AMS3970/1. This specification also defines the procedure and requirements for storage life extension of materials purchased against this specification. It is only applicable for materials that are qualified against AMS3970 (refer to PRI QPL AMS3970) and shall be carried out within the responsibility of the purchaser and under control of its Quality organization.
AMS CACRC Commercial Aircraft Composite Repair Committee
This Purchase Specification (PS), AMS3970/5, specifies the batch release and delivery requirements for the companion non-structural glass fiber fabric prepreg. This specification also defines the procedure and requirements for storage life extension of materials purchased against this specification. It is only applicable for materials which are qualified and shall be carried out within the responsibility of the purchaser and under control of its Quality organization.
AMS CACRC Commercial Aircraft Composite Repair Committee
AMS6885/1 gives information about the technical requirements and qualification procedure for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The repair system includes an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
AMS6885/2 gives specific information about the qualification program for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The prepreg system shall include an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
This document (Technical Specification) gives information about qualification rules and the relation between the different specification parts involved, such as the Technical Specification (TS), the Material Specification (MS), and the Purchasing Specifications (PS).
AMS CACRC Commercial Aircraft Composite Repair Committee
The increasing pressure to decarbonize manufacturing systems is pushing industry beyond conventional lightweighting strategies toward material and process paradigms, capable of delivering functional performance with radically lower environmental impact. In this context, polymer-based composite Additive Manufacturing (AM) offers an underexplored yet highly promising pathway for sustainable production of load-bearing components. This study presents a preliminary comparative cradle-to-gate Life Cycle Assessment (LCA) of a Formula SAE brake pedal, assessing the environmental transition from conventional sheet metal fabrication and finishing operations of Aluminum 7075-T6 to additive manufacturing solutions, with specific focus on Carbon-Fiber-Reinforced Polymer (CFRP) composites. Two topology-optimized designs, respectively for Powder Bed Fusion (PBF) in AlSi10Mg and Material Extrusion (MEX) in Polyethylene Terephthalate Glycol with Carbon Fiber (PETG-CF) are compared to conventional fabrication aluminum benchmark. The analysis is integrated in the product and process design following ISO 14040/14044 standards and is implemented using the Environmental Footprint 3.0 methodology within the 3DEXPERIENCE platform. Results outline that Material Extrusion (MEX) composite manufacturing achieves the lowest environmental impact across all evaluated categories. Compared to conventional manufacturing, the PETG-CF solution enables an approximate 50% reduction in Global Warming Potential and an almost complete elimination of mineral depletion. Unlike metal additive manufacturing, which remains constrained by high process energy demand, MEX benefits from low processing temperatures, minimal auxiliary systems, and highly efficient material deposition. Crucially, these sustainability gains are achieved while maintaining functional performance through design-driven topology optimization. AM composite solutions, by merging advanced material science with additive flexibility, may lead to design approaches which cease to be ‘potential’ enablers of sustainable manufacturing for the Industry 5.0 transition.
Dalpadulo, EnricoRusso, MarioApté MD, RaphaëlleLeali, Francesco
This study investigates the structural improvement of recycled carbon fibre composites through hybridisation with continuous flax fibres to address sustainability concerns and performance limitations. Recycled carbon fibres, while environmentally beneficial, suffer from short, randomized orientations and lower mechanical properties limiting their application beyond decorative uses. This research explores whether incorporating unidirectional flax fibres can enhance rCF behaviour for structural applications. Six hybrid composite layup variants and two plain composites were manufactured using cold compression moulding with Ampro Bio Resin. Each hybrid configuration comprised eight layers, divided into four layers of recycled carbon and four layers of flax fibres oriented at 0°. Complete mechanical characterization was performed following ISO standards for tensile (ISO 527), flexural (ISO 178), and impact (ISO 179) testing. Results demonstrated significant performance improvements in hybrid composites. Among hybrids, layup 2 achieved 212.5 MPa tensile strength whilst layup 3 managed to achieve 20.5 GPa in stiffness. Flexural testing revealed layup 6 achieved the highest flexural modulus of 19.6 GPa among hybrids. Impact resistance improved dramatically with layup 3 demonstrating 186% improvement in energy absorption over recycled carbon fibre. The study confirms that hybridisation creates a positive effect, producing more predictable and durable materials. The complementary behaviour between brittle and ductile materials enhances damage tolerance and structural integrity, establishing a foundation for sustainable engineering materials suitable for automotive applications without compromising reliability.
Hnatyk, DawidChrysanthou, AndreasDe Vuyst, TomIsmail, Sikiru
The study proposes the use of Carbon Fiber Reinforced Plastic (CFRP) sandwich composites configurations for structures interfacing cryogenic tankages. To address the design challenge posed by high thermal contractions in metallic tanks after cryogenic propellant filling, the study incorporates slits near the tank interfaces. Additionally, to minimize the transfer of cryogenic temperatures into these interfacing parts, the sandwich structure features interface end attachment made of thermally insulating Glass Fiber Reinforced Plastic (GFRP) material. Analytical and Finite Element (FE) studies were conducted on a typical cylindrical cryogenic intertank structure to demonstrate the proof of concept. These studies included analytical design using MATLAB based codes, parametric analyses with simplified shell element models and detailed 3D sector models using solid elements. The parametric studies assessed the effects of the number and dimensions of slits to achieve an optimal design, while the detailed 3D sector model provided refined results, validating the adequacy of the proposed concept. Proof-of-concept investigations on the case study sandwich intertank structure demonstrate a notable 30% improvement in mass efficiency compared to the truss configuration and 45% improvement relative to the closed shell metallic configuration, thereby validating the mass efficiency of the proposed design configuration.
Bhalerao, Sandesh PopatGupta, Yogesh KumarMadhukumar, P.
Researchers from CompPair and the European Space Agency have developed a new composite material for spacecraft with an embedded healing agent. European Space Agency, Paris, France Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM, and Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation. Project Cassandra - an abbreviation for Composite Autonomous Sensing and Repair - includes sensors and a heating element within a composite carbon-fiber material, allowing spacecraft to autonomously repair initial stages of damage.
German startup Blackwave is building carbon parts for rocket tanks. Technical University of Munich, Munich, Germany Carbon fiber has become indispensable in high-performance industries such as automotive engineering and aerospace. It's lightweight, extremely durable, and can be shaped in almost any way. The start-up Blackwave, founded at the Technical University of Munich (TUM), specializes in this versatile composite material. What began with custom components for sports cars and aircraft has evolved into the development of high-pressure tanks for space applications. As is so often the case in engineering, a small detail determines technological progress. In the case of rockets, it is the high-pressure tanks that are specially designed for the fuel systems. As rockets are designed to be as light as possible, they lose structural stability when the fuel tanks, known as primary tanks, are emptied. A trick is used to counteract this: alongside fuel combustion, noble gases are released from internal high-pressure tanks, known as secondary tanks. These gases fill the resulting empty space, maintaining structural integrity.
Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM, and Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation.
The intent of this specification is for the procurement of plain weave fabric epoxy prepreg product with 250 °F (121 °C) cure for aerospace applications; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the production quality assurance section (see 4.3).
AMS P17 Polymer Matrix Composites Committee
The intent of this specification is for the procurement of carbon fiber epoxy prepreg product with 250 °F (121 °C) cure for aerospace applications; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the production quality assurance section (see 4.3).
AMS P17 Polymer Matrix Composites Committee
This paper investigates the feasibility of using flax fiber-reinforced composites in combination with additively manufactured polymer cores for helicopter rotor blades. A new rotor blade with flax composite spar and skin laminates and a 3D-printed ASA Aero core was designed to be geometrically equivalent to an existing carbon fiber/foam reference blade of the MERIT rotor test rig and manufactured using identical tooling. Material characterization included compression testing of the printed core at ambient and elevated temperatures, single-lap shear adhesion testing with epoxy laminates, and hygroscopic conditioning of core and laminate specimens. Structural testing comprised static beam bending, experimental modal analysis with axial pre-loading to approximate centrifugal stiffening, and sustained-load creep and recovery testing of the flax blade. The results show that the 3D-printed core provides sufficient compressive stiffness at curing temperature and adhesion to epoxy laminates, enabling its use as an internal consolidation tool during blade manufacturing. Compared to the carbon reference blade, the flax/3D blade exhibits reduced flapwise and lead–lag bending stiffness, altered modal behavior, and pronounced viscoelastic effects, including creep, incomplete recovery, and strong hygroscopic swelling. Component-level hygroscopic tests reveal that moisture-induced mass and thickness changes can generate sufficient internal stresses to locally initiate structural damage. Overall, the study identifies key limitations and design considerations for applying flax fiber composites in primary rotor blade structures.
Gaugelhofer, LukasYavrucuk, Ilkay
Unmanned aerial vehicle (UAV) primary structures require high specific strength and stiffness, traditionally necessitating expensive carbon fiber composites. This study evaluates simulation-driven, additively manufactured polymer alternatives fabricated from PLA and computationally optimized via macroscopic Topology Optimization (TO), mesoscopic Variable-Thickness Lattices (VTL), and uniform Triply Periodic Minimal Surfaces (TPMS). Evaluations were conducted under a superimposed, multi-axial flight envelope. Physical testing demonstrated that VTL architectures maximized the Structural Efficiency Index (SEI) by pushing mass to the extreme geometric fibers and increasing global flexural rigidity. In contrast, mass-constrained TO yielded misleading specific strength due to volumetric starvation and elevated compliance, while the uniform TPMS baseline exhibited favorable specific stiffness but lacked targeted root robustness, resulting in reduced specific strength. Off-axis testing further showed that Diamond lattices dominated vertical bending and inverted impulse loading, whereas Octet and Kelvin geometries more efficiently resolved transverse shear. Experimental data identified a performance-optimized efficiency asymptote in the 73-79 g VTL specimens, which achieved a 19-24% mass reduction relative to a 97 g carbon fiber baseline. To assess assembled-vehicle relevance, the selected fully 3D-printed replacement arms were installed on the baseline quadcopter and subjected to nine dynamic ground tests comprising staircase and cyclic propulsive loading under freestream conditions of 0, 10, and 20 knots. The optimized arms completed the full test matrix without fracture, mount failure, screw loosening, visible yielding, or permanent deformation, demonstrating structural viability in a realistic multi-part UAV assembly without carbon fiber reinforcement.
Scott, ChristopherComer, AnthonyHanan, Jay
The mechanical properties of 3D printed composites have been shown to vary due to the manufacturing infill direction due to artifacts from the printing process. PEEK (Polyether Ether Ketone) and PEEK reinforced with carbon fiber were studied for these experiments because they are widely used for their high strength properties. 3D printed composites that behave with anisotropic characteristics have been evaluated under Laminate Composite Theory (LCT), which can be used to determine the mechanical properties of these 3D printed composites. By changing the orientation of the extruded strands in a 3D printed part, the structure can be optimized in a specific orientation for specific loading conditions, and LCT can be applied for simulating mechanical responses. Three point bending tests were performed on rectangular 3D printed samples and compared to a 3D simulation using LCT for a similar bending load. This allows for the use of LCT in combination with a finite element software such as ANSYS to optimize the design of the 3D printed composite for specific loading conditions without the need of destructive testing. This approach can save time and materials if the simulation testing is proven to be consistent and has been verified using three point bending experimental results. The analysis of the experimental data found that the orientation of the stacking sequence caused a change in the flexural modulus with a maximum percentage difference of 177.63% for the carbon fiber reinforced PEEK and 5.85% for the regular PEEK. Tabular data and plots were created to compare the accuracy of the simulation data with the experimental results. The simulation used LCT to predict a modulus that was compared to the modulus of the recorded data. This was done to compare and confirm the accuracy of the simulation using LCT, the results showed that the largest percentage difference for PEEK CF is 7.774% in the 60 degree orientation and for PEEK the largest difference is 3.166% in the 30 degree orientation. The results show that a product can be printed in an orientation to improve mechanical properties of 3D printed parts with known loading conditions and allow for design and optimization using LCT.
Bradley, CoilinGarcia, JordanSibley, Brian
Carbon fiber-reinforced polymers (CFRPs) have become essential in modern aerospace structures, from fuselage skins and wing components to nacelles, interior structures, and a growing range of primary load-bearing parts. Their high strength-to-weight ratio delivers major benefits in fuel efficiency, payload capacity, and fatigue performance. Yet achieving reliable adhesive bonds on CFRP surfaces remains a persistent engineering challenge. The low intrinsic surface energy of composites - particularly under thermal cycling, vibration, and moisture exposure - limits bond durability unless surfaces are properly prepared. Plasma surface treatment has emerged as a pivotal solution, offering a fast, controllable, and non-destructive way to increase surface energy, improve wettability, and enhance adhesion across complex geometries. This is especially important as the aerospace industry transitions from thermoset to thermoplastic composites (TPCs), which enable faster processing, lower production costs, and better recyclability.
Auburn University's Applied Research Institute in Huntsville is adding some serious fiber to its diet. Auburn University, Auburn, AL In collaboration with Auburn University's Center for Polymers and Advanced Composites (CPAC) and the Department of Aerospace Engineering, the institute recently acquired a CF3D Enterprise Cell - a next-generation 3D carbon fiber composites printer set to define the future of the nation's hypersonic programs. Developed by Idaho-based Continuous Composites, the CF3D system represents a highly specialized advanced manufacturing capability and is the only system of its kind currently operating in Alabama.
In collaboration with Auburn University’s Center for Polymers and Advanced Composites (CPAC) and the Department of Aerospace Engineering, the institute recently acquired a CF3D Enterprise Cell — a next-generation 3D carbon fiber composites printer set to define the future of the nation’s hypersonic programs.
The global push for clean energy has made hydrogen a central element in decarbonizing transport, industrial processes, and energy systems. Effective hydrogen storage and distribution are critical to supporting this transition, and type IV Composite Overwrapped Pressure Vessels (COPVs) have emerged as the preferred solution due to their lightweight, high pressure capacity, hydrogen embrittlement and corrosion resistance. However, the cascade infrastructure used to house and transport these vessels has lagged behind in innovation. Steel-based cascades, while strong, are heavy prone to corrosion, and unsuitable for mobile deployment. This paper introduces a custom designed aluminium cascade system offering a 65% weight reduction while maintaining structural integrity and safety. Designed for mobile use, the system features modularity, better damping, and enhanced corrosion protection. The paper outlines design methodology, material selection, fabrication process, and comparative performance evaluation against steel cascade, supporting the advancement of hydrogen infrastructure.
Parasumanna, Ajeet BabuMuthusamy, HariprasadAmmu, Vnsu ViswanathKola, Immanuel Raju
Carbon fiber-reinforced polymer (CFRP) composites are widely used in aircraft structures for weight reduction due to their high specific strength and modulus. However, their weak interlaminar properties lead to high sensitivity to out-of-plane loads such as impact, making them prone to delamination damage, which threatens flight safety. To enhance interlaminar performance, through-thickness reinforcement technologies, particularly Z-pinning and stitching, have become key research focuses. This paper systematically reviews the manufacturing processes, structural mechanical characteristics, and application progress in aerospace structures of these two mainstream through-thickness reinforcement technologies. Research shows that Z-pintechnology, by implanting metal or CFRP pins, and stitching technology, by sewing multiple fabric layers with fiber threads, both effectively bridge interlaminar cracks, significantly improving the impact resistance of composites. However, the implantation processes introduce defects such as fiber waviness, breakage, and “eye-shaped” resin-rich zones, leading to varying degrees of reduction in in-plane tensile, compressive, and shear properties. Key parameters, such as Z-pin diameter/density/insertion angle, stitch thread diameter/density/pattern, decisively influence the performance enhancement and trade-offs. At the application level, Z-pin technology is mature, suitable for localized toughening of prepreg laminates and joint reinforcement, and is easily integrated into existing processes. Stitching technology, combined with automation and resin infusion processes, demonstrates unique advantages in manufacturing large-scale integrated structures, significantly enhancing damage tolerance. Despite their significant potential, the application of through-the-thickness reinforcement technologies in primary aircraft load-bearing structures remains limited. Their long- term performance under hygrothermal environments and fatigue endurance require further validation. Future efforts should focus on optimizing parameters to balance performance trade-offs and exploring new directions such as integrating health monitoring.
Cui, BoZhang, YongjieZhang, ChuzheJin, Tao
Aiming at the technical bottlenecks of electric vehicles (EVs) in terms of range, energy efficiency and thermal management, this paper proposes an innovative mechanical system design scheme that integrates lightweight materials, topology-optimised structure and mechatronic energy recovery. Through multi-physics simulation and experimental verification, the coupling mechanism between mechanical design and electrochemical performance is revealed, providing theoretical support for the development of energy-efficient electric vehicles. The research adopts a hybrid structure of carbon fiber reinforced polymer (CFRP) and aluminum alloy, and combines it with topology optimization technology to achieve lightweight (18% weight reduction) and improved impact resistance (40% improvement in energy absorption) of the battery box; the design of a bimodal energy recovery system integrating flywheel energy storage and magnetorheological damper, which can achieve an energy recovery efficiency of 82.7% in urban conditions (12.4% higher than that of a single-motor solution); the design of an innovative mechanical system based on fractal theory to mimic an electric vehicle, which can support the development of high energy-efficiency electric vehicles.); the bionic thermal management flow channel based on fractal theory reduces the maximum temperature difference of the battery pack from 8.2°C to 3.1°C, and the pump power loss is reduced by 19%. The results provide a paradigm of engineering practice and theoretical innovation for the optimisation of mechanical systems in next-generation electric vehicles.
Xu, NanxinSong, ZiyangHan, QiyuChen, XiaoxianMiao, ZhengchenSong, Jinlong
The intent of this specification is for the procurement of carbon fiber and fiberglass epoxy prepreg products with 350 °F (177 °C) cure for aerospace applications; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the production quality assurance section (4.3) of this base specification, AMS6891.
AMS P17 Polymer Matrix Composites Committee
The intent of this specification is for the procurement of the material listed on the QPL; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the Quality Assurance section of the base specification, AMS6891.
AMS P17 Polymer Matrix Composites Committee
The intent of this specification is for the procurement of the material listed on the QPL; therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program must refer to the Quality Assurance section of the base specification, AMS6891.
AMS P17 Polymer Matrix Composites Committee
Oak Ridge National Laboratory (ORNL) researchers have overcome a barrier to using a more affordable, dry process for manufacturing the Li-ion batteries used in vehicles and electronic devices. The resulting batteries provide greater electricity flow and reduced risk of overheating.
A futuristic vehicle chassis rendered in precise detail using state-of-the-art CAD software like Blender, Autodesk Alias. The chassis itself is sleek, low-slung, and aerodynamic, constructed from advanced materials such as high-strength alloys or carbon-fibre composites. Its polished, brushed-metal finish not only exudes performance but also emphasizes the refined form and engineered details. Underneath this visually captivating structure, a sophisticated system of self-hydraulic jacks is seamlessly integrated. These jacks are situated adjacent to the four shock absorber mounts. These jacks are designed to lift the chassis specifically at the tyre areas, and the total vehicle, ensuring that underbody maintenance is efficient and that, in critical situations, vital adjustments or emergency lifts can be performed quickly and safely. The design also incorporates an intuitive control system where the necessary buttons are strategically placed to optimize driver convenience. Whether positioned alongside the steering wheel for immediate reach, integrated near the infotainment display for multifunctional control, or mounted within the driver's side door for easy access, these controls underscore a blend of technology and practicality.
Gogula, Venkateswarlu
Researchers at the U.S. Department of Energy (DOE)’s Oak Ridge National Laboratory (ORNL) have developed an innovative new technique using carbon nanofibers to enhance binding in carbon fiber and other fiber-reinforced polymer composites — an advance likely to improve structural materials for automobiles, airplanes and other applications that require lightweight and strong materials.
Researchers at the U.S. Department of Energy (DOE)’s Oak Ridge National Laboratory (ORNL) have developed an innovative new technique using carbon nanofibers to enhance binding in carbon fiber and other fiber-reinforced polymer composites — an advance likely to improve structural materials for automobiles, airplanes and other applications that require lightweight and strong materials.
Innovators at the NASA Glenn Research Center have developed a toughened hybrid reinforcement material made from carbon fiber and carbon nanotube (CNT) yarn for use in polymer matrix composites (PMCs). The new material improves toughness and damping properties of PMCs, enhancing impact resistance, fatigue life, as well as structural longevity.
Stretch broken carbon fiber (SBCF) offers enhanced formability as compared to continuous carbon fiber (CCF). However, robust, quantitative evaluation of forming defects remains a challenge. This study introduces a unified formability index (UFI) that integrates multiple defect types, including texture anomalies, bridging, wrinkling, thickness variation, spring-back, and resin distribution variation (RDV), into a single weighted score. Each defect is ranked on a scale of 0-5 using normalized metrics with a tunable parameter, α, allowing users to balance defect magnitude and frequency as desired. The full scoring pipeline is demonstrated for texture defects using measured data, while normalized legacy scores from previous work are used for non-texture defects to enable complete formability index computation. Case studies on three laminates illustrate how variations in α affect both texture scoring and the overall formability index and demonstrate the geometry-agnostic nature of the updated ranking and UFI systems. This framework maintains compatibility with existing evaluations while offering improved resolution, consistency, and scalability for assessing laminate quality across complex geometries.
Williams, CooperRyan, CecilyCairns, DouglasRidgard, ChristopherNelson, Jared
The demand for carbon fiber reinforced polymers (CFRPs) is growing, especially for use in high-performance applications. Components manufactured of CFRP are made by layering sheets of carbon fibers within a resin matrix. Due to the fibers’ brittle nature, CFRPs are difficult to shape into complex forms, limiting adoption of the material in applications such as vertical lift systems. To address this limitation, researchers at Montana State University, Bozeman (MSU) are developing a new form of carbon fiber called stretch broken carbon fiber (SBCF). SBCF maintains the strength of continuous carbon fibers, while allowing for fiber slip that is used to create a pseudo-plastic strain response needed in most forming processes. Dome and bulge tests were used for comparing the formability response of IM7 MSU SBCF/977-3 with continuous Hexcel IM7 12K/977-3. Results showed increased formability of the MSU SBCF ones due to their ability to stretch under an applied load.
Shchemelinin, YoniNelson, JaredRyan, CecilyBajwa, DilpreetCairns, DouglasRidgard, ChristopherAmendola, Roberta
With performance advances proposed for the Future Vertical Lift suite of aircraft and advancements in the electronic battlefield, it is imperative that advanced materials and concepts be included in the vehicle designs to meet the aggressive weight reduction objectives, structural requirements, and operational environment capabilities. Integrating electromagnetic (EM) shielding during the design process offers an opportunity to make progress towards the performance goals. To this end, efforts must be made to minimize the impact of this shielding to platform weight and structural performance. This article presents work to develop a hybrid multifunctional composite material technology that incorporates copper mesh into a carbon fiber and thermoplastic matrix structural composite material to achieve required levels of EM shielding and high levels of structural efficiency while reducing the overall weight of the system. This article focuses on the design of a representative helicopter tailcone as means of illustrating expected improvements in weight and manufacturing cost. Baselines that include structure fabricated from aluminum and thermoset composite are established and predicted improvements quantified.
Haynes, RobertLuzetsky, HarryPhifer, Ellen
The work done in developing stretch broken carbon fiber technology is described. The objectives of the program include the scale up of the process to demonstrate production feasibility, as well as reducing the maximum filament stretch break length to ~50mm/2” or below, less than half of what was achieved on previous programs. The shorter break length is considered to be critical in order to achieve formability into complex geometries. The new stretch break line at Montana State University, BC3, has been commissioned to achieve the required material characteristics and throughput. To date, 6 tows have been successfully stretch broken simultaneously, representing a significant improvement compared with what was achieved on previous programs. Possible geometries and forming evaluation methods are described. Mechanical testing is to be conducted, including both equivalency testing of continuous vs stretch broken carbon fiber and a later minimal level allowables program. It is expected that there will be no strength reduction when using SBCF in a cured laminate as was the case on the prior programs; this will be verified under the current program with material from the new BC3 stretch break line. Single tow SBCF spools will shortly be available for evaluation by potential prepreg manufacturers and other end users.
Ridgard, ChristopherRyan, CecilyAmendola, RobertaBajwa, DilpreetCairns, Douglas
Composite materials are increasingly utilized in industries such as automotive and aerospace due to their lightweight nature and high strength-to-weight ratio. Understanding how strain rate affects the mechanical and crashworthiness properties of CFRP composites is essential for accurate impact simulations and improved safety performance. This study examines the strain rate sensitivity of CFRP composites through mechanical testing and finite element analysis (FEA). Experimental results confirm that compressive strength increases by 100%–200% under dynamic loading, while stiffness decreases by up to 22% at a strain rate of 50 s−1, consistent with trends observed in previous studies. A sled test simulation using LS-Dyna demonstrated that the CFRP crash box sustained an average strain rate of 46.5 s−1, aligning with realistic impact conditions. Incorporating strain rate–dependent material properties into the FEA model significantly improved correlation with experimental crashworthiness data, reducing discrepancies in peak acceleration, mean acceleration, and displacement by 6.5%, 5.9%, and 6.3%, respectively. These findings reinforce the necessity of accounting for strain rate effects in crash simulations and composite structure design, ensuring more accurate predictions of impact performance and structural integrity in safety-critical applications.
Badri, HesamJayasree, Nithin AmirthLoukodimou, VasilikiOmairey, SadikBradbury, AidanLidgett, MarkPage, ChrisKazilas, Mihalis
Thermoplastic fiber-reinforced polymer composites (TPC) are gaining relevance in aviation due to their high specific strength, stiffness, potential recyclability and the ability to be repaired thanks to their meltability. To maximize their potential, efficient repair methods are needed to maintain aircraft safety and structural integrity. This article introduces a novel repair technique for damaged TPC structures, involving the joining of a repair patch with induction welding using a susceptor material. The susceptor consists of a material with high electrical conductivity and magnetic permeability and therefore reacts stronger to the electromagnetic field than the composite, even if the composite is carbon fiber based. I. e. the thermal energy is specifically concentrated in the repair area. In this study, the susceptor was placed on the patch and also in the welding zone. The repair process begins by identifying and preparing the damaged area, followed by precise scarfing. Care is taken to ensure that the surrounding material remains intact and that an exact stepped structure is created, which enables an optimal bonding with the patch to be used. The customized patch, which fits perfectly in terms of shape and material to the area to be augmented, is then inserted into the structure. Induction heating melts the thermoplastic matrix to join the patch with the structure using a flexible induction mat. The repair process is monitored using thermocouples to ensure even heat distribution, while pressure is maintained through a vacuum bag. The vacuum bag ensures a uniform pressure distribution even on complex curved structures. This adaptable repair method can handle individual damages. It was tested on flat carbon fiber-reinforced polyphenylene sulfide (CF-PPS) structures, showing repairs with nearly 70 % of the original performance for copper mesh susceptors. Optical tests of the specimens confirmed a bonding zone with minimal defects. Overall, this method offers a material-compatible solution for TPC repair in future aviation, advancing aerospace maintenance and offering significant potential for future industry use.
Geiger, MarkusGlaap, AntonSchiebel, PatrickMay, David
Climate-neutral aviation requires resource-efficient composite manufacturing technologies and solutions for the reuse of carbon fibers (CF). In this context, thermoplastic composites (TPC) can make a strong contribution. Thermoforming of TPC is an efficient and established process for aerospace components. Its efficiency could be further increased by integration of joining processes, which would otherwise be separate processes requiring additional time and equipment. In this work, an integrative two-step thermoforming process for hollow box structures is presented. The starting point are two organosheets, i.e. fiber-reinforced thermoplastic sheets. First, one of the organosheets, intended for the bottom skin of the uplift structure, is thermoformed. After cooling, the press opens, the organosheet remains in the press and an infrared heater is pivoted in, to locally heat up just the joining area. Meanwhile, a second organosheet, intended for the top skin, is heated and thermoformed and simultaneously joined to the lower skin, thereby forming the box structure. The process can be referred to as co-consolidation with localized heating of the joining areas. The target of this study was to initially built up a test setup allowing to process single lap shear samples with this concept, test the shear strength (tensile test based on DIN 1465) and compare it with similar tests on samples joined via co-consolidation and resistance welding. The tests were based on organosheets processed from nonwovens made of polyamide 6 fibers and recycled carbon fiber. Resistance welding and co-consolidation gave similar shear strength of about 9 MPa, but the co-consolidation with localized heating reached only around 56 % of the shear strength (around 5.4 MPa). Optical observation shows adhesive failure, indicating that the contact time above temperatures allowing for healing was insufficient and requires further improvement.
Vocke, RichardSeeßelberg, LorenzFocke, OliverDietrich, Jan YorrickJobke, KatrinAlbe, ChristopherMay, David
The segment manipulator machine, a large custom-built apparatus, is used for assembling and disassembling heavy tooling, specifically carbon fiber forms. This complex yet slow-moving machine had been in service for nineteen years, with many control components becoming obsolete and difficult to replace. The customer engaged Electroimpact to upgrade the machine using the latest state-of-the-art controls, aiming to extend the system's operational life by at least another two decades. The program from the previous control system could not be reused, necessitating a complete overhaul.
Luker, ZacharyDonahue, Michael
Composite sandwich beams are widely favored for their high strength-to-weight ratio, so understanding their vibration characteristics is important for optimizing designs in critical industries. This study investigates, through experimental and statistical analyses, the impact of core geometry on the vibration characteristics of epoxy/carbon fiber composite sandwich beams featuring sinusoidal and trapezoidal cores. Modal tests were conducted to determine natural frequencies, damping ratios, and mode shapes. The height and angle of the cores were treated as key independent factors influencing the beams’ vibration characteristics. In both of the cores the damping ratio values increased about 25% and 35% with increasing the height and angle of the sinusoidal and trapezoidal cores, respectively. Additionally, response surface methodology (RSM) was used for statistical analysis of these input parameters’ effects on damping properties, and the optimal values of core’s geometries were determined. Finally, finite element analysis was performed to calculate the vibration properties of the composite sandwich panel that showed good agreement with the experimental results demonstrating strong agreement.
Alwan, Majeed A.Abbood, Ahmed Sh.Farhan, Arkan J.Azadi, Reza
Modern aircraft, ships, and offshore structures are increasingly constructed using fiber-reinforced composite materials. However, when subjected to lightning strikes, these materials can suffer significant structural and functional damage due to their electrical and thermal properties. This study aims to develop a novel finite element (FE) model to minimize the error in estimating the thermal damage caused during lightning strikes. This will aid in design and optimization of lightning protection systems. The developed model introduces a simplified numerical approach to model the lightning arc interaction with CFRP laminate. The existing FE model includes idealized loading conditions, leading to high error in estimation of severe damage area and in-depth damage. The proposed methodology incorporates a more realistic lightning-induced loading pattern to improve accuracy. Several cases are analyzed using available FE methods and compared to the proposed model (case 6) to evaluate the extent of damage. The thermal damage results are validated against baseline experimental data, demonstrating that the proposed FE model reduces the error from over 40% (observed in rest of the cases representing existing FE approaches) to within 10%.
Sontakkey, AkshayKotambkar, MangeshKaware, Kiran
Monocoque is a kind of integrated shell structure technology, which has gradually become the primary choice for various racing teams to make car bodies because of its advantages of small specific gravity and high specific strength. The unit of the monocoque is a carbon fiber composite sandwich structure, which is composed of two layers of carbon fiber skin inside and outside and core material between them. The inner and outer layers of the carbon fiber skin are stacked with carbon fiber composite materials of different directions and types.In this project, we plan to optimize the shape of the monocoque shell using the surface design software Alias, select core materials of different materials and structures, more advanced layups, and obtain feasible layup sequences and core material types through Ansys simulation and Matlab collaborative optimization, which will be verified by three-point bending experiments. Different from the previous lightweight work based a lot on experience, this project improves the lightweight level and strength of the whole vehicle from two more scientific aspects: modeling design and layup and core design.It is noteworthy that we will innovatively try the lattice core material, which has the characteristics of low relative density and high specific strength, and has complexity and designability, compared with the traditional aluminum honeycomb or the foam board, and has more room for optimization. And explore the possibility of using lattice sandwich in some areas, such as the bottom plate, side anti-collision area, etc., and even the whole monocoque.
Cheng, Zhu H.Liu, JJ
This paper introduces an innovative in-wheel electric drive system designed for all-wheel drive Formula Student Electric racing cars. The system utilized AMK's DD5-14-10-POW-18600-B5 model as the driving motor, with a gearbox transmission ratio of 13.2 determined through Optimum Lap simulation. A two-stage gear reducer was integrated into a unified hub-spoke assembly, which connected directly to the ten-inch carbon fiber rim. In this paper, three conventional FSEC planetary gear reducer shafting designs are introduced, and a new shafting structure is proposed. Then the four structures are compared in multiple dimensions. Subsequently, we designed the shafting of the gear group, determined the size parameters of the shafting structure and the bearing type, and completed the verification. The planetary carriers were integrated with the wheel-edge suspension columns. Meanwhile, a special floating brake disc mounting method was employed, which increased the brake disc's heat capacity by more than 15% compared to traditional rivet-fixed floating brake discs, thereby enhancing the brake disc's heat dissipation performance. . This integration allowed the entire electric drive system to be housed within the wheel, resulting in a weight reduction of over 10% and an improvement in overall aerodynamic performance by approximately 5%, compared to conventional designs where the planetary gearboxes are integrated within the suspension columns. Throughout the design process, the strength and stiffness of each subsystem were simulated using ANSYS. Furthermore, MASTA was employed to construct the overall reducer model, simulate the transmission system, and optimize gear modifications, ensuring the safety and reliability of the electric drive system. To further guarantee effective gear lubrication within the gearbox, a gearbox model was built based on the Particleworks platform, and a gearbox lubrication simulation was performed. To further verify the effect, we will make an electric drive system test bench and apply it to the 2025 season racing car of the WUTE team of Wuhan University of Technology and participated in the Formula Student Electric China (FSEC).
Guo, RuijieZeng, JunhaoYang, YuancaiHou, YijieZhu, ZhonghuiXiong, Jiaming
In Formula SAE , the primary function of the frame is to provide structural support for the different components and withstand the applied load. In recent years, most Formula Student teams worldwide to adopt monocoque made of carbon fiber composites, which are lighter and stronger. Enhancing the mechanical performance of carbon fiber laminates has been a key focus of research for these teams. In three-point bending tests, significant stress at the adhesive layer between the skin and the core material at both ends of the laminate, often lead to potential adhesive failure. Consequently, experimental boards often exhibit delamination between the outer skin and the core material, and premature core crushing, which compromises the mechanical performance of the laminate and fails to pass the Structural Equivalency Spreadsheet. Therefore, it is necessary to consider the influence of the bonding factor of toughened epoxy prepreg film on the mechanical properties of the laminated plate. This paper introduces adhesive failure factors into the simulation model, establishes a comprehensive simulation framework based on the bonding performance of GXA-120 toughened epoxy prepreg film, and validates it through actual three-point bending tests, aiming to improve the accuracy of laminate experimental simulations and thereby enhance the efficiency of laminate design for the teams.
Ning, Zicheng
Items per page:
1 – 50 of 513