High-cycle Fatigue Life Extension of Glass Fiber/Polymer Composites with Carbon Nanotubes

The present work shows that the addition of small volume fractions of multi-walled carbon nanotubes （CNTs） to the matrix results in a significant increase in the high-cycle fatigue life. It is proposed that carbon nanotubes tend to inhibit the formation of large cracks by nucleating nano-scale damage zones. In addition, the contribution to energy absorption from the fracture of nanotubes bridging across nano-scale cracks and from nanotube pull-out from the matrix are mechanisms that can improve the fatigue life. An energy-based model was proposed to estimate the additional strain energy absorbed in fatigue. The distributed nanotubes in the matrix appear to both distribute damage as well as inhibit damage propagation resulting in an overall improvement in the fatigue strength of glass fiber composites.

Enhancement of Dimensional Stability of Rigid PVC Foams Using E-Glass Fibers

Short cut E-glass fibers of two different lengths were used to determine the effect of glass fiber length on the dimensional stability of rigid Polyvinyl Chloride (PVC) foam in this study. Glass fibers measuring, 1/16" and 1/32" at different concentrations (0 wt% - 20 wt%) were used to reinforce rigid PVC foams;the PVC foam-glass fiber (PVC-GF) composites were extruded using a single screw profile extruder. The extruded PVC-GF composites were characterized for their dimensional stability, structural, thermal, and mechanical properties. Experimental results show that the dimensional stability, heat resistance, and storage modulus were enhanced without compromising the tensile and flexural strengths of the composites. Thermal shrinkage decreased by almost 55% in composites reinforced with 1/32" GF and by 60% in composites reinforced with 1/16" GFs, with visible improvements to the shape distortion. Overall, foam composites which were prepared with longer (1/16") glass fibers exhibited better mechanical and thermal properties than those prepared with shorter (1/32") glass fibers. Microstructural observations suggest that this is due to better interlocking between the long fibers and the foam cells, which result in better load distribution in the matrix.

Study of the Diffusion Behavior of Seawater Absorption in Multi-Walled Carbon Nanotubes/Halloysite Nanotubes Hybrid Nanofillers Modified Epoxy-Based Glass/Carbon Fiber Composites

In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.

Fabrication and Characterization of Glass Fiber with SiC Reinforced Polymer Composites

Glass Fiber Reinforced Polymeric (GFRP) Composites are most commonly used as bumpers for vehicles, electrical equipment panels, and medical devices enclosures. These materials are also widely used for structural applications in aerospace, automotive, and in providing alternatives to traditional metallic materials. The paper fabricated epoxy and polyester resin composites by using silicon carbide in various proportions along with GFRP. The hand lay-up technique was used to fabricate the laminates. To determine the properties of fabricated composites, the tensile, impact, and flexural tests were conducted. This method of fabrication was very simple and cost-effective. Their mechanical properties like yield strength, yield strain, Young’s modulus, flexural modulus, and impact energy were investigated. The mechanical properties of the GFRP composites were also compared with the fiber volume fraction. The fiber volume fraction plays a major role in the mechanical properties of GFRP composites. Young’s modulus and tensile strength of fabricated composites were modelled and compared with measured values. The results show that composites with epoxy resin demonstrate higher strength and modulus compared to composites with polyester resin.

Production and Properties of Short Jute and Short E-Glass Fiber Reinforced Polypropylene-Based Composites

Short jute fiber (2 - 3 mm) reinforced polypropylene PP-based composites (20% fiber by weight) were fabricated using compression molding and the mechanical properties were evaluated. Tensile strength (TS), tensile modulus (TM), elongation at break (Eb%), flexural strength (FS), flexural modulus (FM), impact strength (IS), and hardness of the composites were found to be 32 MPa, 850 MPa, 12%, 38 MPa, 1685 MPa, 18 kJ/m2 and 96 shore-A, respectively. Then short E-glass fiber (2 - 3 mm) reinforced PP-based composites (20% fiber by weight) were fabricated and mechanical properties were compared with short jute-based composites. Short jute-based composites showed excellent mechanical properties and comparable to short E-glass-based composites. Soil degradation test of both types of composites indi-cated that jute/PP composites significantly lost much of its mechanical properties but E-glass/PP composites retained major portion of its original integrity. Interfaces of the degraded composites were investigated by scanning electron microscopy and supported the biodegradation properties of jute/PP composites.

Effects of Content of Chopped Glass Fibers on the Properties of Silica Filled PTFE Composites

In this work, the polytetrafluoroethylene (PTFE)-based composite substrates were manufactured by mixing, calendering, hot-pressing sintering. The composition of all the samples was PTFE, SiO2 and chopped E-glass fibers. The effects of content of E-glass fibers on the properties of the SiO2 filled PTFE composites were investigated, including density, water absorption, dielectric properties (εr, tanδ), coefficient of thermal expansion (CTE) and temperature coefficient of dielectric constant (τε). The compositions of inorganic materials mixture are (62 ? x) % SiO2 + x % E-glass fiber (x: mass ratio to composites, x = 0, 1, 1.5, 2, 2.5, 3). The results show that as the content of E-glass fibers is 2.5 wt.%, this composite obtains optimal properties, including excellent dielectric properties (εr^2.9123, tanδ~0.0011), acceptable water absorption of 0.075%, temperature coefficient of dielectric constant of 10 ppm/?C and coefficient of thermal expansion of 15.87 ppm/?C.

Static Bending Creep Properties of Glass Fiber Surface Composite Wood

To study the static bending creep properties of glass fiber reinforced wood,glass fiber reinforced poplar(GFRP)specimens were obtained by pasting glass fiber on the upper and lower surfaces of Poplar(Populus euramevicana,P),the performance of Normal Creep(NC)and Mechanical Sorptive Creep(MSC)of GFRP and their influencing factors were tested and analyzed.The test results and analysis show that:(1)The MOE and MOR of Poplar were increased by 17.06%and 10.00%respectively by the glass fiber surface reinforced composite.(2)The surface reinforced P with glass fiber cloth only exhibits the NC pattern of wood and loses the MSC characteristics of wood,regardless of the constant or alternating changes in relative humidity.(3)The instantaneous elastic deformation,viscoelastic deformation,viscous deformation and total creep deflection of GFRP are positively correlated with the stress level of the external load applied to the specimen.Still,the specimen’s creep recovery rate is negatively correlated with the stress level of the external load applied to the specimen.The static creep deflection and viscous deformation of GFRP increase with the increase of the relative humidity of the environment.(4)The MSC maximum creep deflection of GFRP increased by only 7.41%over the NC maximum creep deflection,but the MSC maximum creep deflection of P increased by 199.25%over the NC maximum creep deflection.(5)The Burgers 4-factor model and the Weibull distribution equation can fit the NC and NC recovery processes of GFRP well.

BFRP条带-PVC管材复合加固纤维再生混凝土短柱轴压性能

为了研究BFRP条带-PVC管材复合加固纤维再生混凝土短柱的轴心抗压性能,对13组再生混凝土短柱进行了轴压试验和理论分析。主要研究变量为BFRP条带层数(0层、1层、3层)、BFRP间距(25 mm、37.5 mm和50 mm)和加固方式(无侧向约束、BFRP条带加固和BFRP条带-PVC管材复合加固)。研究结果表明:BFRP条带-PVC管复合加固不仅可以提高试件的极限承载力,还可以改善纤维再生混凝土短柱的破坏形态。在应力-应变曲线的非线性强化阶段,加固方式对试件刚度的影响更为显著。随着BFRP包裹量的增加,试件的峰值应力和极限应变均明显增加。依据试验数据建立的软化段的应力-应变计算模型具有较好的适用性。

Thermally Conductive and Insulating Epoxy Composites by Synchronously Incorporating Si-sol Functionalized Glass Fibers and Boron Nitride Fillers

Glass fibers(GFs)/epoxy laminated composites always present weak interlaminar shear strength(ILSS)and low cross-plane thermal conductivity coefficient(λ⊥).In this work,silica-sol,synthesized from tetraethyl orthosilicate(TEOS)and KH-560 via sol-gel method,was employed to functionalize the surface of GFs(Si-GFs).Together with a spherical boron nitride(BNN-30),the thermally conductive BNN-30/Si-GFs/epoxy laminated composites were then fabricated.Results demonstrate that Si-sol is beneficial to the improvement of mechanical properties for epoxy laminated composites(especially for ILSS).The BNN-30/Si-GFs/epoxy laminated composites with 15 wt%BNN-30 fillers display the optimal comprehensive properties.In-planeλ(λ//)andλ⊥reach the maximum of 2.37 and 1.07 W.m-1.K-1,146.9%and 132.6%higher than those of SiGFs/epoxy laminated composites(λ//=0.96 W.m-1.K-1 andλ⊥=0.46 W.m-1K-1),respectively,and also about 10.8 and 4.9 times those of pure epoxy resin(λ//=λ⊥,0.22 W.m-1.K-1).And the heat-resistance index(THRI),dielectric constant(ε),dielectric loss(tanδ),breakdown strength(E0),surface resistivity(ρs)as well as volume resistivity(ρv)are 197.3℃,4.95,0.0046,22.3 kV.mm-1,1.8×1014Ω,and 2.1×1014Ω.cm,respectively.

THE PHYSICAL SIMULATION ON EXTRUSION PROCESS OF GLASS FIBER COMPOSITE WIRE COATED BY LEAD

The method of manufacturing the composite wire by extruding lead to coated glass fiber is described. The different composite wire that diameter is from 0.5 to 1.0mm has been produced by two kinds of different extruding technology (getting wire along horizontal direction and getting wire along perpendicular direction). The optimal extruding techno- logical parameter has been given in different extruding technology by the physical simulation (H: 300℃, 550kN, 0.16mm. P: 300℃, 215kN, 0.16mm). The effect on the coating speed by other extruding technological parameters in the different extruding technology has been discussed. The extruding temperature and extruding force is higher, the coating speed is faster. It has been pointed, that the affection on the extruding technology by the extruding temperature has also behaved as the extruding temperature rising up spontaneously. The reason for exiting the minimum extruding force and maximum extruding force also has been discussion in this paper. It is also important to the extruding process and coating speed that is the coating clearance.

Influence of Non-smooth Surface on Tribological Properties of Glass Fiber-epoxy Resin Composite Sliding against Stainless Steel under Natural Seawater Lubrication

With the development of bionics, the bionic non-smooth surfaces are introduced to the field of tribology. Although non-smooth surface has been studied widely, the studies of non-smooth surface under the natural seawater lubrication are still very fewer, especially experimental research. The influences of smooth and non-smooth surface on the frictional properties of the glass fiber-epoxy resin composite（GF/EPR） coupled with stainless steel 316 L are investigated under natural seawater lubrication in this paper. The tested non-smooth surfaces include the surfaces with semi-spherical pits, the conical pits, the cone-cylinder combined pits, the cylindrical pits and through holes. The friction and wear tests are performed using a ring-on-disc test rig under 60 N load and 1000 r/min rotational speed. The tests results show that GF/EPR with bionic non-smooth surface has quite lower friction coefficient and better wear resistance than GF/EPR with smooth surface without pits. The average friction coefficient of GF/EPR with semi-spherical pits is 0.088, which shows the largest reduction is approximately 63.18% of GF/EPR with smooth surface. In addition, the wear debris on the worn surfaces of GF/EPR are observed by a confocal scanning laser microscope. It is shown that the primary wear mechanism is the abrasive wear. The research results provide some design parameters for non-smooth surface, and the experiment results can serve as a beneficial supplement to non-smooth surface study.

Experimental Study on Influence of Dimples on Lubrication Performance of Glass Fiber-epoxy Resin Composite under Natural Seawater Lubrication

Bionic non-smooth surface is widely applied in metal and ceramics materials. In order to introduce this technology to high pressure seawater pump, the influence of bionic non-smooth surface on the engineering plastics used in pump should be investigated. The comparative tests are carried out with a ring-on-disc configuration under 800, 1000, 1200 and 1400 r/min in order to research the influence of the bionic non-smooth surface on glass fiber-epoxy resin composite（GF/EPR） under natural seawater lubrication. The disc surfaces are textured with five kinds of pits, which are semi-spherical, conical, cone-cylinder combined, cylindrical pits and through holes, respectively. A smooth surface is tested as reference. The results show that the lubrication performance of dimpled GF/EPR sample is much better than that of the smooth sample under all rotational speeds. The semi-spherical pits surface has more obvious friction reduction than the others, which shows that the least reduction is approximately 43.29% of smooth surface under 1200 r/rain. However, the wear level is only marginally influenced by dimples. The surface morphology investigations disclose severe modifications caused by abrasive wear primarily. The results are helpful to vary friction properties of GF/EPR by non-smooth surface, or provide references to the design of non-smooth surfaces under certain condition.

Performance of Photoluminescence Glass Fiber in Eu^(3+) Doped ZMCB and ZMLB

The photoluminescence glass fiber in Eu^(3+) doped ZnO-MgO-CdO-B_2O_3 isdrawn artificially by high-temperature solid state reaction and glass stream hauling method inhandling of photoluminecent waste material . Its diameter is 0 .01 approx 0.30 mm and its length ismore than 10 m. The strong emission band of Eu^(3+) at 613 nm belongs to ~5D_0- >~7F_2 electricdipole transition, and the emission intensity at 591 nm is 40 percent of that at 613 nm andintensity belongs to ~5D_0- >~7F_2 magnetic dipole transition . It is known to all that Eu^(3+)mainly hold asymmetrical center lattice in local ambient and also possesses symmetrical centerlattice. By fitting decay curves of Eu^(3+) of different concentrations, it is discovered that theluminescence changes from the first order decay to the second order decay while the concentrationsof Eu^(3+) are increased . It is observed by SEM that glass fiber shows smooth surface , low crystalgrowing rate , high density of fracture and shellfish veins of fracture obviously submits ditchform. Meanwhile, a series of mechanics parameters were measured and the spectral behaviors of theglass fiber in Eu doped ZnO-MgO-CdO-B_2O_3 were studied.

Effect of Stacking Sequences on the Mechanical and Damping Properties of Flax Glass Fiber Hybrid

The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites.Therefore,various staking sequences of glass-flax hybrid composites were manufactured and tested in free vibrations.The damping coefficients were identified by fitting the experimental responses of free-free bending vibrations.The obtained results show that the staking sequences and the position of flax fiber layers in the hybrid composites changed the properties,so a classification of different stacking sequences was established.In fact,the hybrid laminate made of two glass external layers placed on both sides of four flax layers is very interesting in term of its mechanical and damping properties.Indeed,it showed better specific bending modulus and loss factor than glass composites with proportions of 31 and 39%,respectively.A study of a structure of this composite has been made to validate the obtained results.

Mechanical Properties of Glass Fiber/Unsaturated Polyester Resin Composite Water Collector

The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize the material of the water collector and improve its mechanical properties.Polyester,a general term of polymer obtained from polyols and polyacids,is a kind of engineering plastics with excellent properties and wide applications.Glass fiber is a reinforced plastic reinforcement material,and the biggest characteristic of it is the high tensile strength and good heat resistance.In this paper,glass fiber reinforced polyester resin composite material is prepared,its tensile properties and bending properties are tested,and the performance of the imported material JK2020B is compared and analyzed.The results show that the elastic modulus along the fiber direction is relatively high,but the interlayer force in the direction of thickness and width is very small.This review provides a guidance for production process.

Recycling of Glass Fibers from Fiberglass Polyester Waste Composite for the Manufacture of Glass-Ceramic Materials

This work presents the feasibility of reusing a glass fiber resulting from the thermolysis and gasification of waste composites to obtain glass-ceramic tiles. Polyester fiberglass (PFG) waste was treated at 550℃ for 3 h in a 9.6 dm3 thermolytic reactor. This process yielded an oil (≈24 wt%), a gas (≈8 wt%) and a solid residue (≈68 wt%). After the polymer has been removed, the solid residue is heated in air to oxidize residual char and remove surface contamination. The cleaning fibers were converted into glass-ceramic tile. A mixture consisting of 95 wt% of this solid residue and 5% Na2O was melted at 1450℃ to obtain a glass frit. Powder glass samples (<63 μm) was then sintered and crystallized at 1013℃, leading to the formation of wollastonite-plagioclase glass-ceramic materials for architectural applications. Thermal stability and crystallization mechanism have been studied by Differential Thermal Analysis. Mineralogy analyses of the glass-ceramic materials were carried out using X-ray Diffraction.

Effect of Silane Coupling Agent on the Flexural Property of Glass Fiber Reinforced Composite Film

Transparent glass fiber reinforced composites films ware fabricated by UV light induced chemical crosslinking of composite materials consisting of glass fiber and UV curable resin in film state. In order to apply film to flexible device, excellent flexural property is required, then the delamination should not occurred between glass fiber and UV curable resin when film is bent. To minimize delamination and improve the interfacial adhesion at interface between glass fiber and UV curable resin, the γ-aminopropyl triethoxy silane and γ-glycid oxypropyl trimethoxy silane were applied for the surface treatment of glass fibers. Silanization of glass fiber surface was checked by scanning electron microscopy and the degree of delamination of composite film was confirmed through the bending test, ASTEM290-96a, used by haze meter.

Fabrication of composite wire of lead coated on glass fiber by extrusion

A new technology of using lead coated on glass fiber to produce continuous wire for battery of electric vehicles (EVs) and hybrid electric vehicles (HEVs) was studied. Some new devices were made to improve the material capability, and the technological parameters were determined. The relationships among different parameters in the new technology were discussed, especially the relationship between the coating speed and other parameters. The microstructure and tensile strength of the composite wire were also analyzed.

Behavioural Modelling of Lips Seal Made with Polytetrafluoroethylene Enriched by Glass Fibers

Polytetrafluoroethylene reinforced with glass fibers is a composite material widely used in industry mainly for the manufacture of seals at the level of the rotary shafts of vehicles and stationary floor machines such as turbines and compressors. However, due to elastic and viscous-plastic properties of this material, it wears quickly under the influence of some external parameters during operation. There are therefore material loss, increased clearance and loss of sealing. This work summarises a series of tests carried out with this material in order to analyse the variation of the friction coefficient due to the roughness of the work piece brought into contact with the PTFE, the linear velocity of contact between them and material yield strength. To do this analysis, we used the method of unconventional design of experiments to model the behaviour of material and consequently make decisions to reduce this wear. The results are shown and deeply analysed in the following text as a polynomial mathematical model, graphs, contours and response surfaces illustrating the holding of this material under the effect of the three parameters mentioned above. The previous PTFE samples enriched with chopped glass fibers are not subjected to axially force this time, contrary to the force applied radially. The advantage of this method is the relative linear velocity at the contact sample-disc and the applied pressure remains constant. Under the action of the weight “P” applied on the sample, it comes into friction with the rotating disc whose roughness changes from experience to another;it is expressed by the values of Ra. Tangential friction force appears at the point of contact and is equilibrated by measured force Fm on the lever. The calculation of the moment relative bench axis caused by 2 forces gives the coefficient of friction. Knowing the values of frictional force Ft by calculation and the weight P, we determine then the friction coefficient.