Glass Fiber Mat Research Articles

Out-of-plane performance of structurally and energy retrofitted masonry walls: geopolymer versus cement-based textile-reinforced mortar combined with thermal insulation.

This paper examines the out-of-plane performance of masonry walls (representative of infills in reinforced concrete frames) which have been upgraded with an outer skin of integrated structural and an energy retrofitting system. The benefits of such an integrated system are mainly cost-related. Nevertheless, before moving to full-scale applications, additional benefits to the structural performance need to be investigated. In this study, the examined configurations of this composite system comprised either thermal insulation boards bonded directly to the wall followed by layers of textile-reinforced mortar (TRM), or thermal insulation boards bonded in-between two TRM layers. Other than the retrofitting layers configuration, the following parameters were also investigated: a) the binder type (cement-based versus geopolymer-based mortars), and b) the textile type (open mesh glass fibre textile versus basalt fibre textile). The results of this experimental study are discussed in terms of failure modes, post-cracking stiffness and ultimate capacities. Overall, this study highlights the mechanical benefits of the TRM plus thermal insulation system while providing insights on the bond performance between the different materials selected. An important finding is that the integrated system is even more effective than a standard TRM application. Finally, the geopolymer mortar seems to be equivalent in terms of performance to the commercially available cement-based mortars.

Modulation of piezoelectricity and mechanical strength in piezoelectric composites based on N0.5B0.51T-BNT nanocubes towards human-machine interfaces

Perceiving mechanical stimuli via piezoelectric nanogenerator (PENG) is attractive for constructing the self-powered sensing system in the field of human-machine interaction. However, the inferior piezoelectricity of the lead-free piezoelectric materials leads to the relatively low sensitivity of PENG. Herein, a 90 nm lead-free off-stoichiometric 0.95Na0.5Bi0.51TiO3-0.05Ba(Ti0.5Ni0.5)O3-δ (N0.5B0.51T-BNT) single crystal was facilely synthesized by hydrothermal method. Compared to stoichiometric 0.95Na0.5Bi0.5TiO3-0.05Ba(Ti0.5Ni0.5)O3–δ, the piezoelectric coefficient presents four folds enhancement, which is associated with the enhanced local structural heterogeneity. By using glass fiber fabric (GFF) as the reinforcing matrix, a mechanically robust PENG based on N0.5B0.51T-BNT is obtained, which delivers a short-circuit current of ∼1.8 μA, and an open-circuit voltage of ∼33.8 V. Meanwhile, the composite film exhibits excellent mechanical strength which can lift the object over 10,000 folds heavier than its own weight successfully. By virtue of the high sensitivity (1.94 V/N, 95.99 nA/N), we assembled the PENG into a 3 * 3 wireless sensing array for the function of the long-distance smart switch and gesture interaction system, which commendably broadens the application scope of the piezoelectric arrays as intelligent sensors.

Efficient and rapid control of Eurasian watermilfoil (Myriophyllum spicatum) by combining benthic mats and hand pulling

AbstractEurasian watermilfoil (Myriophyllum spicatum L.) is an aquatic vascular plant that forms extensive dense beds in lakes. This invader competes with native plants, interferes with aquatic activities, and decreases riparian property values. In Canada, the use of aquatic herbicides is highly restricted. Environmental managers must therefore rely on physical methods such as hand pulling or benthic matting for control. Although these methods are not new, there has been little scientific investigation regarding their effectiveness and cost over multiple years. Benthic matting and hand pulling were used in Lac des Abénaquis (area: 1.2 km2) to control 3.6 ha of M. spicatum beds. Initiated by citizens in 2016, control procedures were scientifically studied in 2020 and 2021. Benthic fiberglass mats were deployed on dense M. spicatum patches for 10 wk. Isolated plants and patches <100 m2 were hand pulled by divers, and the harvested material surfaced via a suction hose or in hand-filled bags. By August 2021, all the M. spicatum patches had been eliminated, and only 560 widely scattered plants remained. Over the last 2 yr of control, hand pulling required 243 person-hours and removed 2,245 kg of biomass. The biomass brought to the surface was 2.4 times higher per person-hour with the suction system than with bags. The use of 1,000 m2 of benthic mats required 47 to 51 person-hours per summer season, including installation, removal, and maintenance. Intensive management (years 1 to 5) using benthic mats and hand pulling cost an estimated Can$185,000 (US$140,000) ha−1 of M. spicatum bed. Hand pulling of scattered individuals (years 6+), estimated at Can$20,000 (US$15,000) per summer, is essential to avoid reinfestation. An invasion of M. spicatum can successfully be managed in small lakes without herbicides, but control remains a costly and long-term endeavor.

Web Stiffening of Additive Manufactured Polylactide (PLA) Railroad Tracks Using Fiberglass Wrapping

Three-dimensional (3D) printed railroad tracks can properly address the rendering of a variety of topographic profiles of naturally occurring landscapes and reduce construction costs. Load tests of PLA railroad tracks found that web failure is a dominant failure mode. This paper evaluates the web stiffening strategies of additively fabricated PLA railroad tracks for rail-guided, micro-people movers (MPMs). To strengthen the track web, web-widening with additional PLA material and stiffening using composite reinforcement using glass fiber reinforced polymer (GFRP) wrap have been investigated. The composite wrapping technique was conducted by bonding fiberglass cloth to both sides of the web using a polymeric resin. Flexural load tests were conducted on the specimens with different infill volume percentages. A linear trend was observed on the peak bending capacities of specimens with PLA infill fiber contents ranging between 20% to 100%. Different failure modes were observed for the different percentage specimens during the tests. When compared to their unreinforced counterparts, the 60% infill specimen had the largest increase in strength about 1,500 N in bending with the addition of GFRP wrap. The tangent stiffnesses of all samples were calculated which showed the 100% infill specimen had the highest increase of approximately 50%. The wrapping reinforcement was found to significantly modify the failure mechanisms of the 3D-printed tracks with different infill volume percentages. The strengthening of the 3D-printed tracks using GFRP wrapping is also shown to be similar to the widening of web sections of the additively printed railroad tracks.

TECHNICAL REQUIREMENTS FOR FIBERGLASS HULLS IN OFFSHORE OIL AND GAS OPERATIONS

This article notes the operation of auxiliary vessels in harsh, aggressive offshore oil and gas field conditions. These vessels transport the necessary equipment and tools, etc. to the oil and gas field trestles. That is, there is wear and tear and ageing of hull structures after a long period of time. As a rule, ship hull structures are made of steel and metals of a certain grade. The aggressive sea water causes corrosion which leads to hull deterioration and gradual destruction. To prevent corrosion, fiberglass material or fiberglass plastics are used. This material is known to be the basic construction material created by scientists and technologists. Fiberglass material, as described in the article, must meet the technical requirements for the operation of auxiliary vessels with hulls made of this material. It is noted that fiberglass material is used in order to save metal and steel. Which is of scientific and practical importance. This material is also used in other areas of engineering and technology. The weight of the material is relatively small compared to metal and steel. According to the technical requirements for the operation of auxiliary vessels, an example is given for increasing the strength of fiberglass material by treatment with a reinforcing agent. The hulls of vessels when transporting the necessary equipment and tools to the trestles of offshore oil and gas fields, are subjected to shock loads of sea waves, as well as the load from the weight of the transported cargo. Consequently, the article notes that hull structures made of fiberglass material, can be one or two or three layers. This gives the ship's hull shock resistance. In this case, the requirement for durability during operation of auxiliary vessels is observed. The scheme of these hulls in cross-sectional view is given. It is noted that repair of hulls made of fiberglass material is easier in comparison with other materials. Deck coating is described, which increases the strength of the running surface of the deck and ensures its durability and carrying capacity. In general, the article describes all the technical requirements for fiberglass hulls and their advantages over materials like metals and steel. It is said that the operation of auxiliary vessels with fiberglass hulls in adverse oil and gas field conditions with the technical requirements for these hulls described in the article, will be of high quality and economical. Keywords: technical requirements, vessel hulls, offshore oil and gas field conditions, fiberglass material.

Installation of geosynthetic interlayers during overlay construction: Case study of Texas State Highway 21

Geosynthetic interlayers in the form of geotextiles, geogrids, and geocomposites have been used to minimize reflective cracks and enhance overlay performance through functions such as stress relief, reinforcement and moisture barrier. However, proper geosynthetic installation and asphalt overlay construction practices are essential to the adequate performance of geosynthetic-reinforced asphalt overlays. In this study, various factors determining the successful construction of a geosynthetic-reinforced asphalt overlay are discussed in light of experiences during the construction of experimental test sections constructed in Texas State Highway 21. The project included nine different types of geosynthetic interlayers including four polymeric geogrid composites, three fiberglass geogrid composites, one fiberglass grid, and a fiberglass paving mat. The experimental test section included both sensor- and non-instrumented sections. The constructability evaluation of such experimental sections revealed that the primary factors influencing tack coat type and application rates include the pre-existing surface condition, geosynthetic type and their asphalt retention capacities. The geosynthetic installation procedures adopted in the experimental sections were proficient and comprised a specialized installation equipment that is capable of pre-tensioning the geosynthetics during the installation to minimize wrinkles and irregularities. Additionally, particularly high temperature of the pre-existing asphalt surface resulted in blistering of geotextile backing and subsequently leading into an excessive bleeding of tack coat through the geosynthetic apertures that resulted in tracking of construction equipment wheels. Recommendations on efficient geosynthetic installation and overlay construction techniques include adopting the tack coat type and application rates based on project-specific conditions, and using such tack coat to determine the asphalt retention capacity of the geosynthetic interlayer to be used in the project. Additional recommendations include minimizing the movement of construction vehicles on top of the geosynthetic interlayer, and adopting asphalt sanding technique to restore the friction between the paver and surface to minimize possible damage to the geosynthetic interlayer.

Numerical simulation to investigate the stealth behaviour of polymer composite

Radar signals expose objects that are present in their vicinity. To avoid being detected by these signals, stealth technology provides an aid. This work focuses on the simulation of the radar-absorbing structure (RAS). A study on the effect of polyvinylidene difluoride (PVDF) and carbon nanotubes (CNT) in glass fiber mats has been done. Spin coating is utilized to increase the β phase in that material. Simulation results showed that at a particular frequency, the composite mat containing PVDF and CNT has the ability to reflect the minimum rays that come from radar, thus providing stealth behavior.

Damage Detection in a Polymer Matrix Composite from 4D Displacement Field Measurements.

Standard Digital Volume Correlation (DVC) approaches enable quantitative analyses of specimen deformation to be performed by measuring displacement fields between discrete states. Such frameworks are thus limited by the number of scans (due to acquisition duration). Considering only one projection per loading step, Projection-based Digital Volume Correlation (P-DVC) allows 4D (i.e., space and time) full-field measurements to be carried out over entire loading histories. The sought displacement field is decomposed over a basis of separated variables, namely, temporal and spatial modes. In the present work, the spatial modes are constructed via scan-wise DVC, and only the temporal amplitudes are sought via P-DVC. The proposed method is applied to a glass fiber mat reinforced polymer specimen containing a machined notch, subjected to in situ cyclic tension and imaged via X-ray Computed Tomography. The P-DVC enhanced DVC method employed herein enables for the quantification of damage growth over the entire loading history up to failure.

Study of the Influence of Plasma Modification on the Characteristics of Glass Fiber Materials

Study of the Influence of Plasma Modification on the Characteristics of Glass Fiber Materials

Rheological characterization and macroscopic modeling and simulation of the molding process of a PA6 Glass Mat Thermoplastic (GMT)

This study targets the characterization and modeling of GMT press molding. The targeted material is TEPEX® flowcore, a long glass fiber mat reinforced polyamide (PA6/GF) manufactured by Lanxess. Press molding of flowcore comprises the sequential stages of material forming and material flow, including challenges like local wrinkling and incomplete mold filling, respectively. Therefore, a sequential modeling approach using a Lagrangian and an Eulerian discretization is pursued. Rheological characterization using rheometer setups and in-mold viscosity measurements reveals a significant anisotropy of viscosity resulting from the predominantly in-plane fiber alignment. Anisotropy of viscosity is successfully modeled and parameterized, enabling a unified material modeling for material forming and material flow. Good predictions are observed for both wrinkling and flow. In summary, molding simulation results reveal that the isotropic modeling of viscosity is sufficient for flow simulation, whereas considering the anisotropic viscosity is essential for the accurate prediction of material forming.

Electro-mechanical behavior of multi-functional glass fiber composites under dynamic Mode-I fracture loading

An experimental study was performed to investigate damage sensing and fracture toughness of multifunctional conductive glass fiber composites under dynamic mode-I fracture loading. Carbon nanotubes (CNTs) were dispersed within the epoxy matrix using a shear mixing and sonicating process. An electrostatic wet flocking process was used to reinforce milled short PAN-based carbon fibers onto each of the layers of glass fiber fabric along the thickness direction in the composites. These layers of flocked fabric were stacked, and a vacuum infusion process was employed to fabricate the composites. The parametric study consisted of two carbon fiber lengths (80 μm and 150 μm) and two fiber densities (1000 fibers/mm2 and 2000 fibers/mm2) and was performed to investigate the damage sensing capabilities of a three-dimensional conductive network generated through CNTs and carbon fibers. A double cantilever beam (DCB) configuration was considered, and a modified Hopkinson pressure bar setup along with a high-speed camera was used to investigate dynamic fracture toughness of the composites. The piezo-resistance response of the composites during dynamic fracture was measured using a modified system of four probes. For comparison, composites were also characterized for fracture toughness and piezo-resistance under quasi-static fracture loading conditions. The addition of short, milled PAN-based carbon fibers significantly increased the fracture toughness of glass/epoxy composites. The piezo-resistance response of the composites was easily correlated with instances of sudden crack growth during static fracture loading.

Composite material with enhanced recyclability as encapsulant for photovoltaic modules

Encapsulation of photovoltaic cells was carried out using a transparent glass fiber reinforced composite with enhanced chemical recyclability based on a matrix of an epoxy resin containing cleavable functional groups. The current-voltage curves showed a decrease of 6.3% on the short-circuit current (Isc) after encapsulation of the cell, lower than the one observed for the reference non-recyclable standard epoxy composite. Its performance stability under thermal cycling, ultraviolet (UV), and damp-heat exposure was evaluated and compared with the one of the reference standard epoxy. Both resins showed good stability performance under UV exposure and thermal cycling accelerated aging. Moreover, a power loss below the 5% allowed by the photovoltaic standard was observed for the recyclable resin after 1000 h of damp-heat exposure, even the pronounced loss of 4.7% in power remains a concern. Regarding the recyclability, the composite was dissolved in acetic acid dissolution and glass fiber fabrics were successfully recovered. A new module was manufactured with these fabrics, showing this time a loss of 12% in Isc comparing with the non-encapsulated cell. Further work will consider improving the moisture barrier properties of the composite, and adjusting the recycling conditions to allow component recovery valid for new modules.

Creation of a Water-Resistant Electrical Insulation on the Basis of Woven-Glass Tapes and Fiberglass Fabrics

Creation of a Water-Resistant Electrical Insulation on the Basis of Woven-Glass Tapes and Fiberglass Fabrics

Upcycling of plastic wastes and biomass to mechanically robust yet recyclable energy-harvesting materials

Plastic pollution is a growing global concern. From the perspective of decarbonization throughout entire lifecycle, the development of mechanically robust yet recyclable materials from sustainable building blocks is highly desirable but remains challenging. Here, we propose a supramolecular in situ assembly strategy to fabricate sustainable materials by integrating reclaimed glass fiber fabric (RGFF, from wind turbine blades wastes) and bio-based epoxidized soybean oil (ESO) vitrimer. The key principle of the design is the construction of supramolecular interface with densely aggregated hydrogen bonds between the resin residual on RGFF and ESO vitrimer, which facilitates the in situ assembly process to form a homogeneous and dense cartilage-like interwoven structure. The resulted materials show not only excellent mechanical properties during service (tensile strength of 152.9 MPa and toughness of 33.9 MJ m−3), but also desirable recyclability in terms of end-of-life options. Furthermore, the favorable dielectric modulation (promote 11.6 times in surface potential) allows the materials to be used in efficient and durable triboelectric energy harvesting. This upcycling strategy to integrate plastic wastes with biomass exhibits 44 %－49 % reduction in carbon footprint, opening up an avenue for sustainable materials as promising alternatives to petrochemical plastics.

Improved ballistic limit velocity from filament-wound fibres as composite cover on ceramic tiles

Hard armour plates are used in body armour for protection against high-velocity threats. The strike face often consists of a single ceramic tile that is covered by a sheet material made of a high-tenacity fibre-composite material. During impact, the ceramic will fracture but at the same time cause erosion and fragmentation of the hard core of the projectile. The composite cover is there to improve the ballistic performance by partly maintaining the integrity of the fracturing ceramic. In this study, a new production method where glass fibre yarns were filament-wound around an alumina tile in a unidirectional 0°/90°lay-up, was investigated. Ballistic testing was conducted with a 7.62 mm armour piercing projectile. The new target design gave a remarkable increase in the V50ballistic limit velocity by as much as 16% compared to a traditional design where a glass fibre fabric was wrapped around the tile. A higher degree of fragmentation of the projectile steel core after perforation was also observed. The high degree of fibre alignment in the filament-wound composite, as opposed to the more wavy fibres in the fabric, is believed to be the main reason for the higher ballistic performance.

The European Commission's Glass Fibre Fabrics Investigation and the Boundaries Between Investment and Trade

AbstractIn a 2020 anti-subsidy investigation concerning glass fibre fabric (GFF) products from Egypt, the European Commission (EC) attributed the Chinese government's conduct to the government of Egypt in a way that raised a systemic question about the boundary between trade and investment. This article argues that despite some overlap between the boundaries of these legal disciplines, the notions of trade and investment remain conceptually distinct. Customary rules of interpretation dictate that World Trade Organization (WTO) covered agreements are construed as facilitating trade relations and no further. Hence, an extension of WTO subsidy rules to cover outward investment promotion measures using the principles of state responsibility is untenable. Such a unilateral approach disproportionately affects the interests of developing countries, harming their efforts to draw green investments. This article recommends that new, balanced rules be designed to promote outward investments while limiting adverse trade impacts.

MWCNT-Coated Glass Fabric/Phenol Composite Heating Panel Fabricated by Resin Infusion Process.

MWCNTs (multiwalled carbon nanotubes) were applied to fiber-reinforced composite materials with phenolic resin having flame retardance for the composite heating panels of railroad vehicles. Instead of dispersing MWCNTs in the matrix, the surface of a pristine plain-weave glass fiber fabric was coated with MWCNTs through a series of dip-coating and drying processes, followed by the resin infusion of the phenolic resin to make the composite heating panel. Before and after the resin infusion process, low percolation thresholds of 0.00216 wt%MWCNT (weight percent of MWCNTs) and 0.001 wt%MWCNT, respectively, were achieved, as were very high electrical conductivities of 47.5 S/m at 0.210 wt%MWCNT and 26.7 S/m at 0.116 wt%, respectively. The low threshold and high conductivity can be attributed to the formation of electrical pathways directly onto the glass fabrics. It was confirmed that mechanical properties such as modulus, strength, and maximum strain were at the same level as those of the pristine glass fabric composite. The heating performance with temperature uniformity, as well as the electrical and mechanical properties, indicates that the resin-infused glass fabric composite having MWCNTs directly coated onto the fabric surface can be a solution for lightweight structural composite heating panels for railway vehicles.

The Reinforcement Effect of Nanoclay on the Damping Characteristics of Hybrid Laminated Composites

The Hybrid Nanocomposite (HNC) laminates are processed by reinforcing the chopped strand mat glass fiber and organically modified montmorillonite clay (OMT) in the polyester matrix. The different percentage by weight (1, 2, 3, and 5% ) of OMT are mixed by high speed shear mixer into the polyester matrix and then the HNC laminates are fabricated by introducing pre-mixed polyester-clay into the CSM by hand lay-up technique. A tensile test result reveals that nanoclay in polyester matrix significantly improves the tensile modulus and strength of HNC. The results also indicate that increasing the amount of nanoclay beyond 2% by weight reduces the mechanical properties but surpassing the basic glass fiber filled system. The reinforcing effect of clay enhances the flexural modulus and strength. Considerable improvement in impact energy absorption is seen from the impact test. Dynamic mechanical analysis shows that incorporation of nanoclay improves the storage modulus and Loss tangent of HNC. Free vibration tests and logarithmic decrement methods are used to predict the dynamic characteristics such as natural frequency, and damping factor for the first four modes of different clay concentrations. Dynamic results show that second phase nanoscale dispersion between the matrix and E-glass fiber significantly enhances the internal damping of hybrid composites.

Decomposition of light hydrocarbons on a Ni-containing glass fiber catalyst

The work is devoted to the study of the novel process of catalytic decomposition of light hydrocarbons on a catalyst at temperatures of 550 °С and 600 °C at various pressures. The CVD process is a new COx-free approach for hydrogen production. A glass fiber fabric was used as a catalyst, which was preliminarily modified by the application of additional outer layers of NiO and porous silica. A technical mixture of propane and butane was used as feedstock. The main purpose is to investigate the effects of pressure and temperature on the production of hydrogen and carbon nanofibers over a glass-based catalyst. As a result of the decomposition of the mixture, the yield of hydrogen was 266–848 L/gcat, and that of carbon nanofibers was 3–10 g/gcat. Increasing the pressure of propane-butane mixture decomposition led to an increase of the catalyst lifetime. The highest yield of hydrogen and carbon nanofibers was achieved at 1 bar and 600 °C.

Synthesis and characterization of cyano-terminated bisphenol AF-type polyarylene ether nitrile

Four novel phthalonitrile-capped polyarylene ether nitrile oligomers containing trifluoromethyl groups (FPEN-Ph) with different molecular weight were designed and synthesized by adjusting the ratio of bisphenol AF (BPAF) and 2,6-dicholorobenzonitrile (DCBN). The molecular structure of FPEN-Ph oligomers were characterized and analyzed by FTIR, 1HNMR and Gel permeation chromatography. Their curing behaviors were studied by Differential scanning calorimetry and rheological tests, and curing kinetics were also discussed by gel method in detail. The glass fiber cloth reinforced FPEN-Ph composites (FPEN-Ph/GF) had flexural strengths of 415.9–497.5 MPa, shear strengths of 34.5–50.5 MPa, and glass transition temperatures ( Tgs) in the range of 211.3°C–416.6°C. The initial thermal decomposition temperatures ( T5%) of various FPEN-Ph cured products were higher than 500°C under nitrogen. Meanwhile, Fracture morphologies showed that the GF/FPEN-Ph composites had excellent interfacial adhesion between FPEN-Ph matrix and GF reinforcement. Herein, the FPEN-Ph resin could be a good candidate for high-performance polymeric composites and the advanced FPEN-Ph/GF composites can be used under high temperature environment.