Advanced Fiber Research Articles

Numerical prediction and experimental validation of free vibration responses of hybrid composite (Glass/Carbon/Kevlar) curved panel structure

This research reveals the effect of hybridisation numerically for different advanced fibre (Glass/Carbon/Kevlar) reinforcement in polymer matrix composite on the eigen-characteristics. The higher-order displacement polynomial kinematics and curvature effect have been utilized for the modelling of the hybrid composite component including the necessary shear deformation. The adequate solution accuracy of the derived hybrid composite mathematical formulation has been examined by comparing with the first-five modal data considering the effect of aspect ratios, numbers of layers and the fibre types with the experimental data. The eigen-frequency solutions are obtained using an isoparametric linear finite element formulation in association with experimental properties for the hybrid composite. Also, the modal responses are obtained via a simulation model considering the individual layer effects of each fibre through the static-structural module of the commercial package (ANSYS). Finally, the influential structural design parameters (thickness ratio and constraint conditions) affecting the frequency characteristics including the geometrical shape are examined using the present numerical model. The computational results reveal that the numbers of layer and type of fibre affect the frequency parameter due to the variation in their stiffness.

TGF-β3 Loaded Electrospun Polycaprolacton Fibre Scaffolds for Rotator Cuff Tear Repair: An in Vivo Study in Rats.

Biological factors such as TGF–β3 are possible supporters of the healing process in chronic rotator cuff tears. In the present study, electrospun chitosan coated polycaprolacton (CS–g–PCL) fibre scaffolds were loaded with TGF–β3 and their effect on tendon healing was compared biomechanically and histologically to unloaded fibre scaffolds in a chronic tendon defect rat model. The biomechanical analysis revealed that tendon–bone constructs with unloaded scaffolds had significantly lower values for maximum force compared to native tendons. Tendon-bone constructs with TGF–β3-loaded fibre scaffolds showed only slightly lower values. In histological evaluation minor differences could be observed. Both groups showed advanced fibre scaffold degradation driven partly by foreign body giant cell accumulation and high cellular numbers in the reconstructed area. Normal levels of neutrophils indicate that present mast cells mediated rather phagocytosis than inflammation. Fibrosis as sign of foreign body encapsulation and scar formation was only minorly present. In conclusion, TGF–β3-loading of electrospun PCL fibre scaffolds resulted in more robust constructs without causing significant advantages on a cellular level. A deeper investigation with special focus on macrophages and foreign body giant cells interactions is one of the major foci in further investigations.

Astronomical Applications of Multi-Core Fiber Technology

Optical fibers have altered astronomical instrument design by allowing for a complex, often large instrument to be mounted in a remote and stable location with respect to the telescope. The fibers also enable the possibility to rearrange the signal from a focal plane to form a psuedo-slit at the entrance to a spectrograph, optimizing the detector usage and enabling the study of hundreds of thousands of stars or galaxies simultaneously. Multi-core fibers in particular offer several favorable properties with respect to traditional fibers: 1) the separation between single-mode cores is greatly reduced and highly regular with respect to free standing fibers, 2) they offer a monolithic package with multi-fiber capabilities and 3) they operate at the diffraction limit. These properties have enabled the realization of single component photonic lanterns, highly simplified fiber Bragg gratings, and advanced fiber mode scramblers. In addition, the precise grid of cores has enabled the design of efficient single-mode fiber integral field units for spectroscopy. In this paper, we provide an overview of the broad range of applications enabled by multi-core fiber technology in astronomy and outline future areas of development.

Experimental and finite element analysis of push-out shear test for adhesive joints between pultruded GFRP and concrete

Adhesively bonded joints have expanded widely in recent years as more and more advanced glass fibre reinforced materials are being utilized in the civil engineering applications. Hybrid pultruded GFRP concrete bonded beams have been proposed as an economical structural solution for building and footbridge applications due to their favourable properties. Evaluation of shear strength for the adhesive joint is considered as the most important parameter for the design of these hybrid beams. However, the absence of standard method for testing GFRP/concrete bonded joints makes the application of this technology in construction work far from being achieved. There is then a need to make more effort to improve design procedure and to understand the behaviour of this assembly. In this context, the present paper aims to characterize the shear test “Push out” in order to provide more information about the influence of the different geometrical parameters on the shear strength of the adhesive joint. For this purpose, experimental and numerical investigations were carried out to investigate the effect of various parameters on the failure load and the failure mode of the specimens such as surfaces treatment, shape of GFRP profile, adherents’ dimensions (width and thickness), adhesive thickness, bonded length and free height. The numerical investigations were performed by three-dimensional (3D) nonlinear Finite Element (FE) model. The constitutive relationship of the pultruded GFRP is modelled by means of a linear orthotropic law, while the concrete behaviour is defined by means of an elastic plastic damage model with a non-local formulation. In order to reduce computing time, interface elements with zero thickness were used to model the adhesive joint with a linear constitutive law. Using this model, stress distributions along the interface were investigated and the effects of different geometrical parameters were discussed.

Application of Advanced Fiber Material for Athletic Sports Shoes

Application of Advanced Fiber Material for Athletic Sports Shoes

Void‐Free Layered Polymeric Architectures via Capillary‐Action of Nanoporous Films

AbstractHere, a nanomaterial with morphology‐controlled nanoscale capillaries is utilized to overcome manufacturing challenges in layered polymeric architectures. It is demonstrated that the capillary pressure from a nanoporous film replaces the need for applied pressure to manufacture void‐free layered polymeric architectures. Manufacturing of aerospace‐grade advanced carbon fiber composites is performed for the first time without utilizing pressure from an autoclave. Combined with a conductive curing approach, this work allows advanced composites to be manufactured without costly oven or pressure vessel infrastructure. The nanomaterial‐enabled capillary pressure is quantified as 50% greater than typical pressures used in such processing, and is anticipated to overcome the limitations imposed by the requirement of high applied pressure in many other applications such as adhesive joining of various bulk materials including metals, press forming, and closed‐mold infusion processing of layered composites and polymers.

Daily Intake of Advanced Glycation End Products, Fibers and Vitamin C: Their Relationship with Nutrition Status in Adolescent Girls

Introduction: Eating habits including food choice are responsible formalnutrition problem in Indonesia. For example, fast foods are very popular in adolescent life, especially who lives in urban areas. The objective of this research is to analyze the relationship of daily intake of Advanced Glycation End products (AGEs), fibers and vitamin C with nutrition status in adolescent girls.Methods: This cross sectional study was conducted in 150 adolescent girls of senior high schools who were in grade X and XI in Kediri city, East Java Province. Data of AGEs, fibers and vitamin C intake were determined using a 24h food recall questionnaire for two alternating days.Nutrition status was based on body mass index for age based on the z-score issued by the Indonesian Ministry of Health. The chi square and multiple logistic regression test was used to analyze the relationship of those variables with nutrition status. The significant level was set up at p value < 0.05.Results: The prevalence of overweight and obese was 26% in adolescent girls. Inadequate daily intake of fibers and vitamin C was commonly found in adolescent girls whilst AGEs were highly consumed by adolescent girls. AGEs intake (OR=1.85; 95% CI: 0.88-3.85; p=0.101), fiber intake (OR=0.92; 95% CI: 0.43-1.99; p= 0.839) and vitamin C intake (OR=0.85; 95% CI: 0.36-1.99; p=0.710) were positively related to nutrition status but it was not statistically significant.Discussion: High intake of AGEs and low intake of fiber and vitamin Cincreases the risk of overweight and obese in adolescent girls, compared to those who have low intake of AGEs and high intake of fibers and vitamin C but it was not statistically significant.International Journal of Human and Health Sciences Vol. 04 No. 02 April’20 Page : 109-113

Covalent functionalization of aramid fibers with zinc oxide nano-interphase for improved UV resistance and interfacial strength in composites

Improving the resistances of organic high-performance fibers to harsh environments and enhancing the interfacial interactions of fiber-reinforced composites have become crucial in various applications. In this report, ZnO nanoparticles (NPs) and ZnO nanowires (NWs) were successfully “grown” on the surfaces of aramid fibers (AFs) by grafting with γ-aminopropyl triethoxysilane (KH550) followed by the growth of nano-ZnO. The surface functionalized AFs exhibited improved UV-resistances. After 168 h of ultraviolet exposure, the tensile retention rates of the ZnO-NP- and ZnO-NW-grafted AFs reached 95.6% and 97.7%, respectively, which were significantly higher than the value of 79.1% of the bare fiber. Meanwhile, the introduction of the KH500 and ZnO formed a nano-interphase, enhancing the interfacial strength of the fiber-reinforced epoxy resin composites. The interfacial shear strengths (IFSSs) of the composites with AF-g-ZnO NPs and AF-g-ZnO NWs were 42.9 and 47.8 MPa, respectively, whereas that of bare AF-reinforced epoxy resin was only 31.2 MPa. Nano-ZnO was physically deposited on the AF surfaces without KH550. The IFSS was 36.4 MPa for the AF-ZnO NP and 38.8 MPa for the AF-ZnO NW, which were lower than those of the grafted composites. Therefore, the chemical grafting nano-ZnO on high-performance fibers provides a new strategy for improving the UV-resistances of advanced fibers and to enhance the mechanical properties of fiber-reinforced composites.

A self-healing, Na+ sensitive and neuron-compatible fiber

A stretchable, self-healing and deformable fiber has the potential to use in artificial intelligence products, such as implantable electronic devices, intelligent adaptive interface system and bionic robots. Advanced fibrous electronics with additional functions including bio-responsive, biocompatibility, and biological tissue reconfiguration remains a great challenge on advanced fiber engineering technology. Herein, we use functionalized single-walled carbon nanotubes (SWCNTs) and poly(sodium acrylate) (PAAS) to fabricate the multifunctional fiber through a hydrogel spinning process. The SWCNTs in fiber exhibit a uniaxial alignment under the fluid shear force in the microchannel. This fiber shows outstanding features: (i) elastic, extremely stretchable (could be stretched up to 1000%), and rapidly self-healing (93% healing efficiency within 5 min), (ii) Na+ ion responsive and deformable, and (iii) favoring nerve tissue reconfiguration.

Development Strategies for China’s Advanced Fiber Materials Industry

China’s chemical fiber volume ranks first in the world and is a pillar industry of the national economy. However, there are still prominent problems regarding the development of the chemical fiber industry and promoting the advanced fundamental fiber materials has become the key to the high-quality development of the chemical fiber and textile industries. This study focuses on three types of advanced fiber materials: differential fiber, high-performance fiber, and bio-based fiber. The status, challenges, and development trends of the advanced fiber materials in China are analyzed. On this basis, the key tasks for the future development of the advanced fiber materials are summarized, including developing key technologies to form representative products, improving the intelligent manufacturing level, strengthening the independent innovation capacity, and enhancing the training of scientific and technological talents. This study also proposes development suggestions from the aspects of industrial development strategy, scientific and technological innovation system, the role of science and technology, internationalization of key enterprises, and coordinated development, hoping to provide a theoretical reference for the high-quality development of China’s fiber materials industry.

Experimental Measurement of the Resistant Load in Injection Pultrusion Processes

Injection pultrusion (IP) process is a manufacturing technique for producing advanced fiber reinforced polymers having constant cross-section. Unlike the traditional pultrusion process, in which fibers are impregnated passing through an open bath of liquid resin, in IP the uncured polymer is directly injected within the advancing reinforcement in a close chamber generally connected to the die. This paper investigates the resistant forces evolution in IP process at different pulling speeds. Resistant loads are mainly due to the interaction between the advancing material and the die cavity walls, inducing residual stress and, eventually, internal defects. These loads are typically classified in three main contributes, namely fiber collimation, viscous drag and solid friction. The latter two are directly related to the resin degree of cure, and, therefore, the overall resistant load is dramatically sensitive to the changes in operative parameters. In this paper, the resistant force acting along the die cavity has been measured using a dedicated experimental setup. Measurements were performed during the pultrusion of glass-reinforced polyester with different pulling speeds to evidence the variations in resistant load as a function of the process velocity.

Deformation measurement within adhesive bonds of aluminium and CFRP using advanced fibre optic sensors

Monitoring the deformation within an adhesive joint during the curing cycle provides valuable information regarding the build-up of thermal strain and stress. Distributed fibre optic sensors are very useful for spatial continuous measurements of deformation or temperature. Integrated into a hybrid joint, the thermal curing process of the adhesive can be monitored. This detailed insight into the joint helps to understand the deformation and thereby also the resulting stress. Analysing the deformation process establishes the foundation to adapt techniques to reduce the thermally induced deformation and thereby the resulting stress.

The Low Cost, High Performance Material for Automotive Application

Recently, composite materials are used in various automotive applications. The reasons for composite materials are low weight and can withstand high strength. The present work focuses on the preparation and characterization of some advanced Fiber metal laminate (FML) like Al/BF with epoxy, Al/CF with epoxy, Al/GF with epoxy and its automotive application. Fiber metal laminate is the arrangement of metal fiber, resin in required stacking order. The required fiber metal laminate was fabricated using compression moulding process and the samples were subjected to wide range of mechanical and thermo mechanical characterizations such as tensile strength, impact, erosion wear and flammability test respectively. All the tests are done as per ASTM standards. The applicability and replaceability of the material with conventional automotive materials were studied and results were tabulated

Stability monitoring of surrounding rock mass on a forked tunnel using both strain gauges and FBG sensors

A geo-mechanical physical model test is conducted to study the structural stability of the surrounding rock mass of a forked tunnel during excavations in this paper. The excavations of the tunnel would result in the redistributions of the stress field and even have significant impacts on the structural stability. To measure the variations of the real-time stress state of surrounding rock mass during excavations, two strain measuring techniques have been utilized to the geo-mechanical physical model test. One is the conventional static resistive strain measuring technique, and the other is the advanced Fiber Bragg Grating (FBG) sensing technique. The methods and working principles how to apply the two techniques on the stress field monitoring in the geo-mechanical physical model test are also introduced. The whole variation process of the stress field during excavations has been collected and analyzed. Then, the testing measuring results are compared with those obtained by numerical simulations, which are found to be in a good agreement. It is finally concluded that better experimental results for the stress field during excavations could only be obtained by the combination of the static resistive stain measuring technique and the FBG sensing technique.

Probabilistic damage evolution in masonry strengthened with FRCM subjected to aggressive environment

This paper concerns the applications of advanced Fibre Reinforced Cementitious Matrix (FRCM) systems on existing masonry structures. At the state of the art, it shows that the FRCM-to-masonry bond is affected significantly by substrate properties and environmental conditions. For this purpose, an experimental campaign was realised recreating different experimental scenarios, and the results thereby achieved were critically and comparatively discussed. In particular, specimens constituted of two types of fired-clay bricks (either with a single brick or a running bond masonry) were reinforced with a carbon fibre grid, externally glued by means of a cementitious or a lime-based matrix, and then exposed to salt crystallisation induced by capillarity over several months. Visual observation combined with laser profilometer measurements revealed a progressive deterioration of the surface with material loss and signs of bulging between the composite - masonry interface. Pull-off tests on deteriorated samples confirmed the progressive weakening of the bond in terms of nominal strength. To interpret the amount of data, a novel probabilistic model was proposed, apt to predict possible damaging effects on the surface of reinforced masonry elements.

Use of Pressured-Air for Cotton Lint Cleaning

Saw-type lint cleaner (STLC) was most efficient lint cleaner in cotton ginning. However, STLC damaged fiber quality. An air-bar lint cleaner (ABLC) was developed and evaluated to preserve cotton fiber quality. The ABLC used pressurized-air to remove non-lint materials from cotton fiber. During lint cleaning process, non-lint materials attached to the fiber were blown off the fiber without the fiber making aggressive mechanical contact with a grid bar in conventional saw-type lint cleaner (STLC). It was expected using this concept that the fiber quality could be preserved by reducing the damage from mechanical impact of the fiber against the grid bar. Preliminary testing of the ABLC prototype showed that ABLC generated less lint waste and had a higher turnout rate than STLC. Use of ABLC could save 2.8 kg of lint in each 225 kg bale of cotton. The High Volume Instrument (HVI) analysis indicated the fiber properties in fiber length, uniformity, short fiber content, and color were not significantly different between ABLC and STLC. However, the Advanced Fiber Information System (AFIS) tests showed STLC had better performance than ABLC in fiber length and short fiber content while the trash and dust content with ABLC was lower than the STLC. More research was necessary to further prove the concept of ABLC and improve its performance in preserving cotton fiber quality.

Experimental study on fatigue behavior of butt-welded thin-walled steel plates strengthened using CFRP sheets

Abstract Welded steel joints in structures are susceptible to fatigue failure. In this context, advanced carbon fiber reinforced polymer (CFRP) possess a demonstrated potential for the fatigue strengthening of steel structures. However, limited information is available on CFRP strengthening of butt-welded joints, which are the most common joint types in steel structures. This paper presents a study on fatigue behavior of butt-welded thin-walled steel plates strengthened using CFRP sheets. A total of 34 specimens with both single-sided and double-sided strengthening were performed via constant amplitude tensile fatigue loading, and another four specimens were employed for hot-spot stress measurement. The effect of CFRP strengthening on fatigue behavior was investigated by varying the strengthening scheme (single-sided or double-sided) and the number of CFRP sheet layers. Test results showed that the fatigue life of butt-welded steel plates with CFRP strengthening increased by approximately one to ten times when compared to the fatigue life of butt-welded steel plates without CFRP strengthening. Triple-layered double-sided specimens seemed to exhibit the best effect on fatigue life; their fatigue strength at 2 million cycles increased by 34% compared to that of specimens without CFRP strengthening. Specific fatigue design S–N curves of butt-welded thin-walled steel plates with and without CFRP strengthening were proposed directly. The fatigue test results were used to calibrate a fatigue design approach for CFRP strengthened butt-welded steel plates. In addition, the effect of CFRP strengthening on stiffness degradation was also discussed.

A Novel Facile and Green Synthesis Protocol to Prepare High Strength Regenerated Silk Fibroin/SiO2 Composite Fiber

In this work, regenerated silk fibroin (RSF) and silicon dioxide (SiO2) composite fiber was successfully extruded by wet spinning method. The effect of SiO2 addition on structure of the composite fiber at microscopic level is studied, which subsequently correlated to the mechanical performance. The best concentration ratio for composite fiber is identified by screening SiO2 concentration from 0.025 w/w% to 0.5 w/w%. The experimental results revealed that the SiO2 at a low concentration of 0.1 w/w% was well distributed. The breaking stress, breaking strain and Young’s modulus at 0.1 w/w% SiO2 addition of the RSF fibers increased considerably compared to the neat RSF fibers from 243±3 to 458±21 MPa, 51±4 % to 54±7 % and 6.34±0.55 to 11.69±1.12 GPa, respectively. To the best of our knowledge, this is the first report for RSF/SiO2 composite fiber. We believed the insight provided in this report which looks into the structural evolution should be beneficial to the future design and building of other advanced functional fibers.

Advanced Fiber Optic and Ultrasonic Sensor Systems for Structural Health Monitoring of Pipes in Nuclear Waste Sites

Abstract Nuclear waste sites across the United States and other countries store, transfer and vitrify nuclear waste. These sites often require transfer pipelines for high and low level radioactive wastes in the form of solids/slurries, fluids including chemicals. Since, these pipelines deal with harmful nuclear wastes, structural health monitoring is of utmost importance. Pipelines are continuously monitored to enhance the safety of the people and environment around the facilities. Monitoring may involve leak, crack detection and wear (in the form of corrosion or thinning). Current research builds on author's previous work on sensors for erosion and thermal monitoring in pipes and plates [1, 2, and 3]. Present work involves a) validation and monitoring of a novel advanced Fiber Optic Sensor System to detect cracks and leaks in carbon steel pipes and b) the use of Ultrasonic (UT) sensors to detect thinning in pipe sections due to erosion-corrosion using small coupons. The fiber optic sensors developed by CEL [4], are used in conducting engineering scale testing on an in-house designed and assembled erosion pipe flow loop. The loop consists of 2 and 3 inch straight and elbow sections of carbon steel replicating the pipelines at the sites. Three fiber optic sensors are placed at critical locations around the loop. The equipment also includes a communication box and a laptop device for data acquisition. The sensor system uses a combination of fiber optic and acoustic technologies to accurately identify the location of a pipeline leak or crack. Sensors capture the changes in pressure caused by the fluid/slurry flowing through the loop. A “zone” is defined as the distance between any two sensor points. When any two sensors simultaneously detect a leak, a determination can be made as to how far from each sensor the activity is occurring and “zero in” on the event. A number of zones may be linked together to manage vast expanses of pipeline. Sensors provide instantaneous event data to the hardware (the interrogator), and the interrogator may be located great distances from the actual pipeline in secure, environmentally protected areas. Multiple Interrogators may be linked together that are simultaneously streaming real-time data to the command and control software. Event notifications may then be managed from the customer's control room, or immediately “pushed” to a variety of mobile devices to alert personnel of the situation [5]. Additionally, Ultrasonic (UT) sensors are used for thickness measurements in pipes. The objective is to measure the wear in pipelines due to erosion-corrosion using small scale erosion coupons. These erosion coupons are made of carbon steel with ½ inch in diameter and 1 inch height. The method involves insertion of the coupons into holes drilled in the pipe sections of the erosion loop. This process ensures that the coupons are in contact with the flow stream and hence eroded in a minute scale over a period of time. The coupons have a slot for insertion of the sensors to measure the thickness in real-time when needed. Upon successful testing of the coupon and sensors, the method can be used to predict the erosion rates and hence the remaining useful life of the pipe sections without having to replace them unnecessarily. Hence, the present research conducts structural health monitoring of carbon steel pipes using fiber optic and UT sensors. The sensors have been validated and verified for their potential future deployment in the nuclear waste sites.

Interfacial Polymerization of Cellulose Nanocrystal Polyamide Janus Nanocomposites with Controlled Architectures

The widespread use of renewable nanomaterials has been limited due to poor integration with conventional polymer matrices. Often, chemical and physical surface modifications are implemented to improve compatibility, however, this comes with environmental and economic cost. This work demonstrates that renewable nanomaterials, specifically cellulose nanocrystals (CNCs), can be utilized in their unmodified state and presents a simple and versatile, one-step method to produce polyamide/CNC nanocomposites with unique Janus-like properties. Nanocomposites in the form of films, fibers, and capsules are prepared by dispersing as-prepared CNCs in the aqueous phase prior to the interfacial polymerization of aromatic diamines and acyl chlorides. The diamines in the aqueous phase not only serve as a monomer for polymerization, but additionally, adsorb to and promote the incorporation of CNCs into the nanocomposite. Regardless of the architecture, CNCs are only present along the surface facing the aqueous phase, resulting in materials with unique, Janus-like wetting behavior and potential applications in filtration, separations, drug delivery, and advanced fibers.