Woven Carbon Fiber Fabric Research Articles

Experimental and numerical investigation of patch effect on the bending behavior for hat-shaped carbon fiber composite beams

Abstract In this study, reinforced composite panels with hat-shaped profile were produced from woven carbon fiber fabrics by vacuum infusion method. Holes were drilled on the crown surface of these panels and repaired with composite patches. The mechanical behavior was examined by performing a three-point bending test on the obtained patched and unpatched specimens. The contribution of the repair to the failure load of the damaged specimens under bending load has been clearly determined. In the numerical part, Hashin damage criterion was used for the beginning of damage. For damage progression, both Continuum Damage Mechanics and Material Property Degradation methods were preferred and compared. In the analysis carried out using the finite element package program Workbench, the cohesive zone model (CZM) was added to the model and its effect on the damage behavior and load of the composite structure was determined. As a result of the experiments and analyses, it was seen that the maximum contact force of the specimens under the bending load decreased by 29.8 % by increasing the number of holes on the specimen surface from 1 to 3. The maximum contact force was determined to increase by 18.52 % due to repairing the three-hole specimens with a patch.

Thermoforming Simulation of Woven Carbon Fiber Fabric/Polyurethane Composite Materials

A finite element simulation was utilized in this work to analyze the thermoforming process of woven carbon fiber fabric/polyurethane thermoplastic composite sheets. In the simulation that may be classified as a discrete method, the woven carbon fiber fabric was treated as an undulated fill yarn crossed over an undulated warp yarn, and the resin was considered separately. Then, they were combined to represent the composite sheets. To verify this simulation, bias extension tests under three constant temperatures were executed. After that, the composite was thermoformed into a U-shaped structure and small luggage. From the bias extension tests, the finite element simulation and material properties of the fiber and resin were confirmed. From the comparison of the thermoformed products, the present simulation could provide the deformed profile and fiber-included angles and has good agreement with the experiment. The results also indicate that the stacking sequences of [(0°/90°)]4 and [(+45°/−45°)]4 have quite different product profiles and fiber-included angles.

Experimental and Numerical Study of Strengthening Prestressed Reinforced Concrete Beams Using Different Techniques

This study aimed to evaluate the static response of prestressed reinforced concrete beams strengthened in their flexure and shear properties using different strengthening techniques, steel plates, and externally bonded woven carbon fiber fabric (WCFF). The experimental work involved testing twenty large-scale prestressed reinforced concrete beams with a length of 3000 mm, and cross-sections measuring 400 mm in height and 200 mm in breadth were cast in the factory and tested in the laboratory. Four beams without prestressing served as the reference beams; two unbonded pre-tensioned beams served as the control beams, and the remaining fourteen beams were strengthened with steel plates and externally bonded woven carbon fiber fabric (WCFF). Eight of the beams were strengthened with 4 mm thick steel plates and tested under a monotonically increasing load with manual readings recorded. The remaining six beams were strengthened with 0.5 mm thick WCFF and tested under a monotonically increasing load with manual readings recorded. The variables considered included the strengthening techniques (FRP composite sheets, steel plates), the types of strengthening (slices, U-shaped), and the flexural and shear capacities of the strengthened beams. All the implemented strengthening techniques yielded enhancements in both the flexural and shear strength outcomes of the beams compared to their respective controls. The most significant increase in load capacity, whether in terms of ultimate load or first crack load, for the prestressed concrete beams’ flexure properties occurred when strengthening with U-shaped steel plates. Additionally, the greatest reduction in deflection at the point of reaching the maximum load for the prestressed concrete beams, in terms of their flexure properties, was observed when strengthening with U-shaped steel plates. Similarly, the maximum load increase for the prestressed concrete beams, in terms of their shear properties, was achieved through strengthening with U-shaped woven carbon fiber fabric wrapping. Furthermore, a finite element model was created to simulate various experimental specimens. The finite element model’s results exhibited harmony with the experimental results, affirming the efficacy of the presented finite element model.

Properties of multi-walled carbon nanotubes grown three-dimensional (3D) woven carbon/epoxy multiscale composites: Experimental study

Multiwalled carbon nanotubes (MWCNTs) were grown onto the surface of woven carbon fiber fabrics (CFFs) by using a chemical vapor deposition method. The mechanical and electrical properties of MWCNTs grown three-dimensional (3D) woven carbon/epoxy multiscale composite (CP-gCNT-E) structures were experimentally investigated. The warp directional flexural and interlaminar shear strength of CP-gCNT-E was slightly decreased by 18.26% and 28.32%, respectively compared to the pristine sample. However, the CP-gCNT-E composite at 20 °C showed 595.82% (7.0 folds) higher electrical conductivity than the pristine. On the other hand, delamination was suppressed via three dimensional vertically aligned three dimensional networks of grown carbon nanotubes (gCNTs) in the through-the-thickness direction of multiscale composite with various failure mechanism including entangled gCNT straightening, CNT bridging, pull-out, and stick-slip along with CNTs, carbon filament and matrix breakages which caused a stress dampening and slowing down the crack propagation. In addition, this network topology in the structure enhanced its electrical conductivity. Therefore, the CP-gCNT-E composite was considered as “damage tolerant” material.

A New Stress-Based Formulation for Modeling Notched Fiber-Reinforced Laminates.

Laminated plates are often modeled with infinite dimensions in terms of the so-called Whitney-Nuismer (WN) stress criteria, which form a theoretical basis for predicting the residual properties of open-hole structures. Based upon the WN stress criteria, this study derived a new formulation involving finite width; the effects of notch shape and size on the applicability of new formulae and the tensile properties of carbon-fiber-reinforced plastic (CFRP) laminates were investigated via experimental and theoretical analyses. The specimens were prepared by using laminates reinforced by plain woven carbon fiber fabrics and machined with or without an open circular hole or a straight notch. Standard tensile tests were performed and measured using the digital image correlation (DIC) technique, aiming to characterize the full-field surface strain. Continuum damage mechanics (CDMs)-based finite element models were developed to predict the stress concentration factors and failure processes of notched specimens. The characteristic distances in the stress criterion models were calibrated using the experimental results of un-notched and notched specimens, such that the failure of carbon fiber laminates with or without straight notches could be analytically predicted. The experimental results demonstrated well the effectiveness of the present formulations. The new formula provides an effective approach to implementing a finite-width stress criterion for evaluating the tensile properties of notched fiber-reinforced laminates. In addition, the notch size has a great effect on strength prediction while the fiber direction has a great influence on the fracture mode.

Multi‐functional structural supercapacitor based on manganese oxide‐hydroxide nanowires modified carbon fiber fabric electrodes

AbstractCarbon fiber is an ideal candidate for preparing electrode of structural supercapacitors, while its low specific surface area is a vital factor which restricts energy storage performance. In this study, MnOOH nanowires (MnOOH‐NWs) are in‐situ deposited onto the woven carbon fiber fabric (WCF) surface through an effective one‐step hydrothermal treatment to prepare MnOOH‐NWs modified WCF (MnOOH‐NWs@WCF) structural supercapacitor with appreciable electrochemical performance. The areal capacitance of MnOOH‐NWs@WCF structural supercapacitor reaches 77.1 mF/cm2, which is two orders of magnitude higher than that made from neat WCF electrode. The increase in areal capacitance is primarily due to the presence of conductive networks and abundant ion storage sites constructed by the MnOOH‐NWs. Meanwhile, flexural strength and modulus of the MnOOH‐NWs@WCF structural supercapacitor are 30.3 MPa and 1.8 GPa, respectively. Interestingly, the resultant structural supercapacitor also enables electromagnetic interference (EMI) shielding based on the conductive networks constructed by the WCF and MnOOH‐NWs, and the maximum EMI‐shielding effectiveness (EMI‐SE) is 59.1 dB. Consequently, a highly integrated multi‐functional structural supercapacitor is developed, which cannot only be applied as energy storage module and load bearing component but can also be adopted to protect electronic devices from the electromagnetic pollution.

Fabrication of Bipolar Plates from Thermoplastic Elastomer Composites for Vanadium Redox Flow Battery.

A vanadium redox flow battery (VRFB) is a promising large-scale energy storage device, due to its safety, durability, and scalability. The utilization of bipolar plates (BPs), made of thermoplastic vulcanizates (TPVs), synthetic graphite, woven-carbon-fiber fabric (WCFF), and a very thin pyrolytic graphite sheet (GS), is investigated in this study. To boost volumetric electrical conductivity, WCFF was introduced into the TPV composite, and the plate was covered with GS to increase surface electrical conductivity. Created composite BPs acquire the desired electrical conductivity, mechanical strength, and deformation characteristics. Those properties were assessed by a series of characterization experiments, and the morphology was examined using an optical microscope, a scanning electron microscope, and atomic force microscopy. Electrochemical testing was used to confirm the possibility of using the suggested BP in a working VRFB. The laminated BP was utilized in a flow cell to electrolytically convert V(IV) to V(V) and V(II), which achieved comparable results to a commercial graphite bipolar plate. Following these experiments, the laminated bipolar plates’ surfaces were examined using X-ray photoelectron spectroscopy, and no evidence of corrosion was found, indicating good durability in the hostile acidic environment.

Improving the saline water evaporation rates using highly conductive carbonaceous materials under infrared light for improved freshwater production

Because of the growing population and scarcity of limited freshwater resources, one out of three people in the world do not have access to safe drinking water today; thus, there is an urgent need to address this global concern. Desalinating sea water using renewable energy concepts can be one of the most efficient freshwater solutions for water scarcity issues. We hypothesized that the freshwater scarcity problem could be addressed using effective desalination processes associated with renewable energy and highly porous materials. The primary objective of this study is to investigate the capability of enhancing the saline water evaporation rates using thermally and electrically conductive carbonaceous materials. This study used commercially available carbon felt, woven carbon fiber fabrics, and carbon fiber reinforced composites (60% carbon fiber) to evaporate the saline water with different percentages of salt concentrations. Tap water (or 0 wt% water), 1.5 wt% saline water, and 3.0 wt% saline water sources were prepared and used in the saline water desalination process under simulated solar infrared (IR) light with a power of 250 W. The test results exhibited that the carbon felt water evaporation rate was about 5.37 kg m−2 h−1 with a water temperature of 97.9 °C for 3.0 wt% saline water, which is 32% greater than the base cases and considerably higher than other selected carbonaceous materials. Here, 3.0 wt% saline water represents the average salt concentration of the earth's ocean water, and the high surface area carbon felt seems an effective solar-driven water evaporator for this water. This research provides the potential to deliberate highly durable carbon materials for future freshwater production.

Influence of the Epoxy Resin Process Parameters on the Mechanical Properties of Produced Bidirectional [±45°] Carbon/Epoxy Woven Composites.

This work focuses on investigating the curing process of an epoxy-based resin—Aerotuf 275-34TM, designed for aerospace applications. To study the curing degree of Aerotuf 275-34TM under processing conditions, woven carbon fiber fabric (WCFF)/Aerotuf 275-34TM composite laminates were produced by compression molding using different processing temperatures (110, 135, 160, and 200 °C) during 15 and 30 min. Then, the mechanical behavior of the composite laminates was evaluated by tensile tests and correlated to the resin curing degree through Fourier-transform infrared spectroscopy (FTIR) analysis. The results show the occurrence of two independent reactions based on the consumption of epoxide groups and maleimide (MI) double bonds. In terms of epoxide groups, a conversion degree of 0.91 was obtained for the composite cured at 160 °C during 15 min, while the measured tensile properties of [±45°] WCFF/Aerotuf 275-34TM laminates confirmed that these epoxy resin curing processing conditions lead to an enhancement of the composite mechanical properties.

Loading rate effect of the interfacial tensile failure behavior in carbon fiber–epoxy composites toughened with ZnO nanowires

This paper attempts to study the loading rate effect of interface tensile failure behavior of carbon fiber-epoxy composites toughened with ZnO nanowires (ZnO NWs). ZnO NWs were grown onto woven carbon fiber fabrics through a two-step hydrothermal method, the growth time was carefully controlled to vary the nanowire length. Subsequently, a series of quasi-static and dynamic transverse fiber bundle (TFB) tensile tests were carried out under different loading velocities, ranging from 1 × 10−6 m/s on the universal testing machine to 9 m/s on the electromagnetic Hopkinson bar. A 2D representative volume element (RVE) model has been established to identify the load transfer and failure behavior of the ZnO NW modified interface. The results show that under quasi-static loading, the maximum TFB tensile strength improvement owing to ZnO NWs was about 36.9% and 16.5% when compared with the pristine fibers and the fibers with surface sizing. However, due to the loading rate enhancement of the interface bonding strength, the corresponding values were decreased to 13.9% and 5.0% under dynamic loading. Besides, nanowires with medium length are recommended, because too long nanowires shall reduce the matrix impregnation space between fibers, and the microcracks from the fiber/matrix interface can easily deflect into the matrix along the nanowires. This side-effect may neutralize the enhancement mechanism of ZnO NWs when their length increases to a certain extent.

Optimizaition for formability of plain woven carbon fiber fabrics

How to take full advantages of the strong designability of plain woven carbon fiber fabric is a key problem urgently needed to be addressed in the application of plain woven carbon fiber fabric reinforced thermoplastics (PW-CFRTPs). This study explored formability of plain woven carbon fiber fabric experimentally and numerically through stamping process, and attempted to develop efficient multiobjective optimization for further improving formability of plain woven carbon fiber fabric. First, the mechanical properties and formability of the carbon fiber fabric were characterized using the experimental tests, and then the finite element (FE) analysis involving the hypoelastic constitutive model was carried out to capture non-orthogonal behaviors of the fabric. Second, influences of blank holding force as well as blank holding area (BHA) on the formability of the fabric were investigated, and the forming characteristics including shear angle distribution, wrinkling strain and draw-in features were analyzed using the validated finite element model. Finally, a global multiobjective optimization algorithm based upon the Kriging Believer strategy was presented to optimize the formability of the fabric. The results indicated that the wrinkling strain along fiber increased with increasing shear angle; and the formability of carbon fiber fabric was largely improved through the optimization in comparison with the baseline design.

Investigation on Mode I Fracture Toughness of Woven Carbon Fiber-Reinforced Polymer Composites Incorporating Nanomaterials.

This study experimentally investigated the effects of nanomaterials and interface fiber angle on the mode I fracture toughness of woven carbon fiber-reinforced polymer (CFRP) composites. Three different types of nanomaterials were used: COOH-functionalized short multi-walled carbon nanotubes (S-MWCNT-COOH), multi-walled carbon nanotubes (MWCNTs), and graphene nanoplatelets (GnPs). Double cantilever beam specimens were composed of 12 woven carbon fiber fabrics with/without 1 wt% nanomaterials, and were manufactured using the hand lay-up method. Furthermore, two different stacking sequence series were used; the first series comprised only on-axis carbon-fiber fabrics (0° or 90°), and the second series comprised both on- and off-axis carbon-fiber fabrics (0° or 90° and ±45°). The test results showed that adding S-MWCNT-COOH, MWCNTs, and GnPs significantly increased the mode I fracture toughness of the CFRP composites for both the stacking sequence series. Moreover, the specimens that used only on-axis carbon fiber fabrics exhibited higher fracture toughness values than those of the specimens that used on- and off-axis carbon fiber fabrics together. In addition, an empirical model was established to predict the fracture toughness of the CFRP composites with nanomaterials by using on- and off-axis carbon fiber fabrics together, and the prediction results showed a good agreement with the experimental results.

Low-velocity impact, bending, and compression response of carbon fiber/epoxy-based sandwich composites with different types of core materials

This study focuses on the investigation of the effects of different core types on the low velocity impact, three-point bending and out-of-plane compression loading performance of sandwich composites. Three core materials were selected: Balsa wood, PVC foam, and Ayous wood. The facesheets of sandwich composites were produced by woven carbon/epoxy. Balsa and PVC foam are widely used in sandwich composites as core materials. In this study, Ayous wood, which is the lightest tree after Balsa, was used as core material in addition to traditional core materials. Woven carbon fiber fabrics with an areal density 200 g/m2 as reinforcement and epoxy matrix were used to produce the sandwich composite. Vacuum-assisted resin infusion molding method was used to manufacture composite panels. A number of tests under various impact energy levels for three different sandwich composites were conducted with Fractovis Plus impact testing machine in order to investigate the energy absorption capacity of sandwich composites. Maximum contact forces, absorbed energies, and the maximum deflections of sandwich panels were obtained for each impact energy level. Despite having the same facesheets, Ayous core sandwich composites possess a higher perforation threshold than Balsa and PVC foam sandwich composites. The perforation threshold of Balsa, PVC foam, and Ayous sandwich composites are 85, 72, and 170 J, respectively. In addition, the Ayous core sandwich composites have better bending and compression strengths. The bending strength of the Ayous sandwich composite is higher about six times than PVC sandwich composite and about two times than Balsa sandwich composite.

Evaluation of Mechanical Properties of Press and Injection Hybrid Molded Products Using CNT Grafted Plain Woven Carbon Fiber Fabric at Rib Roots

Evaluation of Mechanical Properties of Press and Injection Hybrid Molded Products Using CNT Grafted Plain Woven Carbon Fiber Fabric at Rib Roots

Back Cover: Advanced Engineering Materials 5∕2019

Advanced Engineering MaterialsVolume 21, Issue 5 1970015 Back CoverFree Access Back Cover: Advanced Engineering Materials 5∕2019 First published: 21 May 2019 https://doi.org/10.1002/adem.201970015AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract The protective HfC coating is uniformly deposited on the woven carbon fiber fabric at 1200°C by chemical vapor deposition based on thermodynamic calculation. H2 partial pressure in a HfCl4–C3H6–H2 system has a significant effect on the yield, composition, and morphology of the HfC coating. As H2 partial pressure becomes higher, nanostructures are more favorable than a continuous film but the co-deposition of excess carbon in HfC is effectively suppressed. Further details can be found in the article 1800730 by Daejong Kim and co-workers. Volume21, Issue5May 20191970015 RelatedInformation

Post-buckling behavior of carbon fiber epoxy composite plates

In this study, the pre-buckling and post-buckling behaviors of layered composite plates which were made of woven carbon fiber fabric with a circular hole in the middle were investigated experimentally and numerically. Firstly, load-displacement graphs of composite plates with different hole diameters were experimentally obtained under compressive load. Then the numerical load-displacement graphs of the plates were found with the ANSYS package program which used the finite element method. As a result, after linear buckling experimental and numerical results were found to be compatible with each other. In addition, damage behavior of plates after buckling with the aid of Tsai-Wu damage criterion was obtained similar to experimental results. The increase in hole diameter did not change the load-displacement behavior characteristics of the plates after buckling. However, it has reduced maximum damage load and maximum failure displacement. The stress at the perimeter of the hole increased significantly with the increase of the vertical displacement with immediately after the buckling but later was not significantly affected by this increase.

Bending Properties of CFRTP Laminate Using CNT Grafted Carbon Fiber

Carbon Fiber Reinforced Thermoplastics (CFRTP), which have a short production cycle time and high specific strength and stiffness, are focused on in the automobile industry. Generally, the mechanical properties of FRP are affected by the interfacial strength between the reinforcing fiber and matrix, so the control of the interfacial strength between the reinforcing fiber and matrix is important. Compared to CFRP with epoxy resin, the interfacial strength between the reinforcing fiber and matrix of CFRTP is relatively low. Recently, a method to improve the interfacial strength between the reinforcing fiber and matrix by grafting Carbon Nanotube (CNT) on the carbon fiber has been developed. In this study, the bending properties of CFRTP laminates using CNT grafted plain woven carbon fiber fabric were clarified. Bending strength of CFRTP laminates using CNT grafted plain woven carbon fiber fabric were higher than that using as-received plain woven carbon fiber fabric.

Cryogenic machining of carbon fiber reinforced plastic (CFRP) composites and the effects of cryogenic treatment on tensile properties: A comparative study

Abstract Carbon fiber reinforced plastics (CFRPs) are prone to damage locally during machining due to the applied cutting forced and generated heat. Cryogenic machining can reduce the heat generated damages of CFRPs by utilizing cryogenic liquids instead of conventional cutting fluids. The goal of this study is to investigate milling performance of CFRPs in cryogenic medium. For this, a new cryogenic machining approach was adopted to slot milling of CFRPs by submerging the workpiece within a cryogenic liquid. The CFRPs were fabricated via vacuum assisted resin transfer method by using woven carbon fiber fabric as a reinforcement and epoxy as a matrix. Machining performance was evaluated based on the resulting cutting force, delamination factor, surface roughness, and surface damage. Moreover, the influences of cryogenic coolant on the tensile properties, fracture surface microstructure, and machined surface of the CFRP laminates were analyzed with scanning electron microscopy (SEM). SEM analysis revealed that combination of different damage modes such as debonding, micro matrix crack, fiber pull out, and bundle pull out, delamination, and fiber breakage were observed. The results showed that cryogenic machining approach provided less damage formation on the machined surface, reduced delamination factor and surface roughness but increased resulting cutting force during machining of the CFRPs. On the other hand, there was a slight improvement (about 3%) of the tensile properties for the CFRPs exposed to cryogenic coolant due to matrix hardening and increasing in the fiber strength and shear strength.

A complete carbon counter electrode for high performance quasi solid state dye sensitized solar cell

Abstract The proposed research describes the design and fabrication of a quasi-solid state dye sensitized solar cells (Q-DSSCs) with a complete carbon based counter electrode (CC-CE) and gel infused membrane electrolyte. For CE, the platinized fluorinated tin oxide glass (Pt/FTO) was replaced by the soft cationic functioned multiwall carbon nanotubes (SCF-MWCNT) catalytic layer coated on woven carbon fiber fabric (CFF) prepared on handloom by interlacing of carbon filament tapes. SCF-MWCNT were synthesized by functionalization of cationised lipase from Candida Ragusa. Cationised enzyme solution was prepared at pH ∼3 by using acetic acid. The cationic enzyme functionalization of MWCNT causes the minimum damage to the tubular morphology and assist in fast anchoring of negative iodide ions present in membrane electrolyte. The high electrocatalytic activity and low charge transfer resistance (RCT = 2.12 Ω) of our proposed system of CC-CE shows that the woven CFF coated with cationised lipase treated carbon nanotubes enriched with positive surface ions. The Q-DSSCs fabricated with CC-CE and 5 wt% PEO gel infused PVDF-HFP membrane electrolyte exhibit power conversion efficiency of 8.90% under masking. Our suggested low cost and highly efficient system of CC-CE helps the proposed quasi-solid state DSSCs structure to stand out as sustainable next generation solar cells.

Barium Titanate Film Interfaces for Hybrid Composite Energy Harvesters.

Energy harvesting utilizing piezoelectric materials has become an attractive approach for converting mechanical energy into electrical power for low-power electronics. Structural composites are ideally suited for energy scavenging due to the large amount of mechanical energy they are subjected to. Here, a multifunctional composite with embedded sensing and energy harvesting is developed by integrating an active interface into carbon fiber reinforced polymer composites. By modifying the composite matrix, both rigid and flexible multifunctional composites are fabricated. Through electromechanical testing of a cantilever beam of the rigid composite, it reveals a power density of 217 pW/cc from only 1 g root-mean-square acceleration when excited at its resonant frequency of 47 Hz. Electromechanical sensor testing of the flexible multifunctional composite reveals an average voltage generation of 23.5 mV/g at its resonant frequency of 96 Hz. This research introduces a route for integrating nonstructural functionality into structural fiber composites by utilizing BaTiO3 coated woven carbon fiber fabrics with power scavenging and passive sensing capabilities.