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Fiberglass and Glass Technology

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Chapters (11)

Continuous glass fibers can be formed from melts with a wide range of compositions and viscosities. This chapter reviews pure silica fibers which are formed from highly viscous melts, silicate glass fibers with 50–70% SiO 2 which are formed from moderately viscous melts, aluminate glass fibers with 50–80% Al 2 O 3 , as well as yttria-alumina-garnet (YAG) glass fibers which are formed from invis-cid (literally non-viscous) melts. Commercial glass fibers are made for a variety of applications from pure silica rods and from silicate melts containing 50–70% SiO 2 and 10–25% Al 2 O 3 . Boron-free, essentially boron-free, and borosilicate E-glass are general-purpose fibers. ERC-glass offers high corrosion resistance, HS-glass offers high-strength composites, D-glass offers a low dielectric constant, and A-glass offers the possibility of using waste container glass for less demanding applications. Keywords Continuous glass fibers · Viscous and inviscid fiberglass melts · Glass melting and fiber formation · Experimental and commercial glass fibers · Commercial E-glass · ECR-glass · D-glass · HS-glass and A-glass fibers · Structures and properties 1.1 Overview: Glass Melt and Fiber Formation The viscosity of glass melts depends on the SiO 2 content, the crystallization resis-tance at the liquidus temperature of these melts depends, at the same Al 2 O 3 level, on the SiO 2 :RO ratio (RO = CaO + MgO), and the modulus of the resulting glass fibers depends on the Al 2 O 3 content at the same SiO 2 content.
Incumbent fiberglass compositions rely on decades of commercial experience. From a compositional point of view, many of these melts require more energy than needed in their production, or emit toxic effluents into the environment. This chapter reviews the design of energy- and/or environmentally friendly E-glass, HT-glass, ECR-glass, A-glass, and C-glass compositions, which have lower viscosities or fiber-forming temperatures and therefore require less energy in a commercial furnace than the respective incumbent compositions and/or do not contain ingredients which are of environmental concern.
Fiberglass is a versatile and cost-effective reinforcement for composites. Many processes, resins, and forms of fiberglass facilitate this versatility. The design, engineering, manufacture, and properties of fiberglass-reinforced composite products from diverse thermoset and thermoplastic resins are described. The attributes of fiberglass-reinforced composites include its mechanical and chemical properties, lightweight, corrosion resistance, longevity, low total system cost, and Class A surface properties. Specific examples illustrate the importance of the form of the fiberglass reinforcement and of the interfacial bond between the glass fibers and the matrix resin in optimizing composite properties. In addition, recent advances are described with regard to the fabrication of fiberglass-reinforced wind turbine blades.
Fiberglass imparts numerous positive benefits to modern printed circuit boards. Reinforced laminate composites have an excellent cost-performance relationship that makes sense for most applications. At the leading edge of the technology, new glass fibers with improved properties, in combination with the best resin systems available, are able to meet very challenging performance, cost, and regulatory demands while remaining manufacturable.
High-strength glass fibers play a crucial role in composite applications requiring combinations of strength, modulus, and high-temperature stability. Compositions in the high-strength glass group include S-glass and R-glass, which are used for applications requiring physical properties that cannot be satisfied by conventional E-glass. Additional compositions are also available for specialized applications requiring extreme performance in any one area. The main competition for high-strength glasses in the marketplace comes from carbon and polymer fibers. Ultimately, the product of choice is based on a compromise between cost and performance and will vary depending on the application.
The principles behind commercial glass manufacture are discussed in terms of production-related considerations: meltability, workability, refining, and economics. Examples of the implementation of these principles are given to explain their importance and their technical impact. The historical development of the key commercial glasses are charted over the centuries up to the present day, providing insight into how and why we have arrived at today's commercial glass compositions and detailing their strengths, weaknesses, and variations.
In order to be energy efficient, environmentally friendly and sustainable, commercial glass production in the 21st century must evolve and some of the technologies and methodologies that will make this possible are discussed. Development and implementation of energy-efficient and environmentally friendly soda-lime-silica glass compositions are discussed in terms of environmental and legislative requirements; the reduction of melting energies and atmospheric emissions; glass properties and the effects of individual glass components and raw materials; and technologies that can help glassmakers to meet new requirements. This in-depth treatment provides detailed step-by-step analysis, with appropriate examples, of the opportunities for compositional reformulation, new raw materials, new melting and abatement technologies, and some of the practical and economic effects that such changes will provide.
The energy/enthalpy functions of solids and melts are investigated as a function of temperature. Several thermal effects can be understood on an atomic scale surprisingly well by energy levels and wave functions of the bonding electrons and their interaction with the oscillating atoms. Among these effects are the melting transition, the glass transformation, the thermal expansion, structural phase transitions, and relaxation effects occurring near the glass transition temperature, Tg. Glass formation is favored if sufficient strong directed bonds are present between the constituents and the melting entropy per particle is sufficiently small.
First, a model based on linear algebra is described by which the thermodynamic properties of industrial multi-component glasses and glass melts can be accurately predicted from their chemical composition. The model is applied to calculate the heat content of glass melts at high temperatures, the standard heat of formation of glasses from the elements, and the vapor pressures of individual oxides above the melt. An E-fiber glass composition is depicted as an example. Second, the role of individual raw materials in the melting process of E-glass is addressed, with a special focus on the decomposition kinetics and energetic situation of alkaline earth carriers. Finally, the heat of the batch-to-melt conversion is calculated. A simplified reaction path model comprising heat turnover, content of residual solid matter, and an approach to batch viscosity is outlined.
The employment of sensors during glass melting represents a major prerequisite for an improved process control leading to higher production yields. In situ sensoring techniques can be divided into two groups: on the one hand, techniques which extract information of glass melt properties, e.g., oxidation state and concentrations of relevant polyvalent species (such as iron, sulfur, chromium) and on the other hand, techniques which monitor the furnace atmosphere with respect to toxic emissions (e.g., SO2, NOx ) and combustion species (e.g., CO, CO2, H2O). Nowadays it is feasible not only to install early warning systems indicating deviations from target glass properties, but also to implement process control systems which enforce a stable and reproducible glass melting. Examples are given for the redox control of green glass melting utilizing high portions of recycled cullet and the redox control of amber glass melting.
A plasma arc melter is a modular high-intensity skull melter capable of rapidly melting a wide variety of materials, both conductive and nonconductive. Although its commercial use to melt and process metals is well known, the method is less well known as a method of melting glass. Extensive research has been conducted by several organizations into the use of skull melting of glass using plasma arcs. This research has shown plasma melting to be a promising technology that can achieve high efficiencies, high temperatures, extreme flexibility, low capital cost, rapid changeovers of glass formulas, and minimal scrap. Plasma melting lends itself to modular melting in which each step of the glass melting process is partitioned into functional modules, which can greatly improve melting efficiency and throughput. Also, plasma arc melting has been shown to be a promising technology for rapidly and inexpensively producing "synthetic minerals" melted from common commercial oxides.
... The most important melt properties are: the fibre-forming viscosity (η) that is quoted between 10 1.8 to 10 2.5 Pa·s and its corresponding temperature, the liquidus temperature at which crystals can form within hours and remain in equilibrium in melt and the processing temperature range, that is the difference between fibre-forming and liquidus temperature. To ensure a stable fibre spinning process, the processing window (∆T) should be at least 70 K [20,21]. Finally, a chemical coating, or sizing, is applied. ...
... This shows that BG with high contents of sodium, such as 45S5, are less favourable for processing, while glasses with low contents, such as 13-93 (53SiO 2 -6Na 2 O-12K 2 O-5MgO-20CaO-4P 2 O 5 wt%) [26], show reduced tendency to crystallise and are therefore easier to process. To be able to form bioactive glass fibres into textiles, they should be as thin as the technical glass fibres (4-20 µm) and must have sufficient tensile strength, which, for example, is quoted as about 2000 MPa for unsized and between 2500 to 4000 MPa for sized E-glass fibres [21,27]. ...
... With the help of these determined parameters, the fibres for all glass compositions except S53P4 were drawn from previously produced glass blocks using the nozzle drawing method and fibres of diameters below 15 µm were obtained. These diameters correspond to technical glass fibres, for which a range of 4 to 20 µm is reported [21]. ...
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Bioactive glasses have been used for many years in the human body as bone substitute. Since bioactive glasses are not readily available in the form of endless thin fibres with diameters below 20 µm, their use is limited to mainly non-load-bearing applications in the form of particles or granules. In this study, the spinnability of four bioactive silicate glasses was evaluated in terms of crystallisation behaviour, characteristic processing temperatures and viscosity determined by thermal analysis. The glass melts were drawn into fibres and their mechanical strength was measured by single fibre tensile tests before and after the surface treatment with different silanes. The degradation of the bioactive glasses was observed in simulated body fluid and pure water by recording the changes of the pH value and the ion concentration by inductively coupled plasma optical emission spectrometry; further, the glass degradation process was monitored by scanning electron microscopy. Additionally, first in vitro experiments using murine pre-osteoblast cell line MC3T3E1 were carried out in order to evaluate the interaction with the glass fibre surface. The results achieved in this work show up the potential of the manufacturing of endless bioactive glass fibres with appropriate mechanical strength to be applied as reinforcing fibres in new innovative medical implants.
... The plain weave woven composite is assumed to be composed of S-2 glass fiber and SC-15 epoxy, for which various fiber properties are given in [44,45] and matrix properties in [46]. The constitutive behavior of both fiber and matrix phases are modeled by a small strain isotropic linear elastic model given as ...
... FE analysis of the RVEs are conducted under multi-axial loading, by perturbing one of the material parameter values, while keeping the other parameters at the values given in Table 2. The corresponding values are: Variants of the Young's modulus in Set A for S-2 glass fiber are obtained from [44,45], while variants for the S-15 epoxy matrix modulus in Set B are obtained from [46]. Fig. 10 shows the homogenized strain-stress responses in the 2 direction (perpendicular to the plane of the yarns) of the RVEs with different material parameters. ...
Article
This is the first of a two-part paper that develops a validated 2-level parametrically-upscaled continuum damage mechanics (PUCDM) model for multiscale modeling of damage evolution in plain weave woven composites, characterized by multiple levels of hierarchy. The two-level PUCDM models, viz. PUCDM-1 and PUCDM-2, bridge three levels of composite hierarchy. The PUCDM-1 model corresponds to the constitutive model for yarns in the mesoscopic woven RVE with representation of the morphology and mechanisms of underlying unidirectional fibers in level-1 of the hierarchy. The PUCDM-2 model is used for modeling the structural scale composite behavior with morphological and mechanisms representation from the underlying levels 2 and 1. Functional forms of constitutive coefficients in the PUCDM-1 and PUCDM-2 models, in terms of representative aggregated micro- and meso-structural parameters (RAMPs), material properties, and damage states, are generated by machine learning (ML) methods. The ML algorithms operate on databases of volume-averaged response variables, obtained from the simulation of lower-level RVEs. The validation tests, comparing PUCDM model results with homogenized variables from lower scale analysis demonstrate very good accuracy. The two-level PUCDM models are capable of predicting the stress–strain and damage evolution with high computational efficiency and accuracy.
... Without the reinforcement phase, the structural integrity of PCBs is rather ineffective. Nevertheless, the ultimate strength of PCBs is not only dependent on the intrinsic strength of glass fibre; factors such as weaving patterns and the number of fabric layers also influence the composite strength of PCBs [34]. ...
... In addition, the thermal strain that is trapped in the PCBs during PCB manufacturing can also lead to PCBs deformation [54]. A multitude of other studies also corroborated this finding and highlighted the failure of the PCBs during alternating adoption of heating and cooling due to the creation of thermal residual stress [34,37,55,56] Liu et al. [37] surmised that the thermal shock pre-treatment is a potential alternative for metal recovery without undergoing comminution, as copper foil can be easily separated from the substrate by using a hand, though this is not reported or recommended at the industrial scale. . Thermo-gravimetric analysis (TGA) curve of WPCBs for thermal shock (Region 1, [14]) and pyrolysis (Region 2, [57]). ...
Article
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Waste electrical and electronic equipment or e-waste generation has been skyrocketing over the last decades. This poses waste management and value recovery challenges, especially in developing countries. Printed circuit boards (PCBs) are mainly employed in value recovery operations. Despite the high energy costs of generating crushed and milled particles of the order of several microns, those are employed in conventional hydrometallurgical techniques. Coarse PCB pieces (of order a few centimetres) based value recovery operations are not reported at the industrial scale as the complexities of the internal structure of PCBs limit efficient metal and non-metal separation. Since coarse PCB particles’ pre-treatment is of paramount importance to enhance metal and non-metal separations, thermal, mechanical, chemical and electrical pre-treatment techniques were extensively studied. It is quite evident that a single pre-treatment technique does not result in complete metal liberation and therefore several pre-treatment flowsheets were formulated for coarse PCB particles. Thermal, mechanical and chemical pre-treatments integrated flowsheets were derived and such flowsheets are seldom reported in the e-waste literature. The potential flowsheets need to be assessed considering socio-techno-economic considerations to yield the best available technologies (BAT). In the wider context, the results of this work could be useful for achieving the United Nations sustainable development goals.
... High dielectric constant and selectivity of chemical modification put silica among the most widely used substrates in the design of micro-and nano-electronic devices [1][2][3][4]. It is a major component in optical fibers used in telecommunications and glass fibers used in fiber reinforced composite applications [5][6][7][8]. ...
Conference Paper
In this paper, a silica (SiO 2) surface in the presence of water has been studied using molecular dynamics (MD) simulations. Water and silica models have been created separately, relaxed and then put side by side to study the silica-water interface. All the intra-and inter-molecular interactions have been described by the reactive force field ReaxFF. From the molecular simulations, structural properties of water and silica, silica surface reactivity, diffusion of water molecule into silica have been investigated. For molecular simulations, open source MD code LAMMPS has been used.
... As the estimation of viscosity in the low-temperature range was significant for determining the drawing temperature, the former was estimated using the MYEGA equation in the present study. During the down-drawing process, the fiber-forming temperatures of typical glass fibers have viscosities ranging from log 2.5 to 3.0 dPa s (Wallenberger, 2010). The corresponding viscosity in the present study was observed in the temperature range 1466e1503 K. ...
Article
Increasing concerns about environmental issues have led to more attention being paid to the recycling of mining wastes and smelting byproducts. In the present study, the utilization of gold tailings, waste limestone, red mud, and ferronickel slag was investigated for producing continuous glass fibers. To verify the applicability of the down-drawing process, the viscosity of the present mixture was measured in the molten state at a high temperature. The viscosity in the low temperature range was estimated using the Mauro–Yue–Ellison–Gupta–Allan equation. Compared to other commercially used basalt fiber systems, a similar fiber-forming temperature in the range of 1466 K–1503 K with viscosities ranging from log 2.5 to log 3.0 dPa s, was observed, which indicates the applicability of the down-drawing process. Measurements of the tensile strength and the Young's modulus of a single filament were carried out following standard test methods. In spite of the thick diameter of the present filament, the fiber produced in the present study exhibited a Young's modulus of 60 GPa–80 GPa, which was found similar to those of other commercial fibers. It is expected that a higher tensile strength will be achieved by reducing the diameter of the filament lower than 10 μm by increasing the drawing speed. Therefore, utilization of the present mixture; mining wastes and smelting byproducts, is feasible for producing continuous glass fibers.
... 14 Nylon is used because of their high tensile strength, elasticity, luster, excellent scratch resistance, highly resistant to abrasion and chemicals. They are also not affected by insects, fungi, animals, and rots [15][16][17] and hence used for fishing purpose. Glass fibers, the utmost common reinforcement material for manufacturing polymer matrix composites, gained its way by their high tensile strength, high chemical resistance, and insulating properties. ...
Article
Composite partition sheets were prepared by vacuum infusion process using noncombustible glass fiber and waste nylon along with polyester matrix. The waste nylon materials obtained in the form of discarded fishing nets were reinforced in sheets with T90° orientation. They were then coated using two types of fumed silica nanopowders mixed in polyester resin. Two types of coated and corresponding bare hybrid composite samples were examined for their various properties. Appreciable values for mechanical properties were obtained for all the hybrid sheets which are more pronounced for the nanocoated sheets. Furthermore, horizontal flammability tests proved that the fumed silica-coated sheets have better flame-retardant characteristics. With constant heat flux of 50 W/m², the specimens were investigated for the peak heat release rate (HRR) and fire reaction properties like total oxygen consumed, average specific mass loss rate, total smoke release, and average HRR which gave good results for the nanocoated sheets. Moreover, water-absorbing properties of the hybrid sheets were generally less and it was better in the case of hydrophobic fumed silica-coated samples. These low cost and less weight composite sheets were successfully developed and the results obtained were encouraging, which can be used as partition sheets in the construction of affordable buildings.
... Those matrices may be polyester, vinylester, epoxy or polypropylene. The compositional range for each element of the glass fibre determines its significant characteristics, including the presence of inorganic oxides during the manufacturing process of the glasses [11]. Different glass fibres may be distinguished by letter designation, as compliant with ASTM specifications. ...
Article
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The aim of this work was to analyze the effects of hybridizing kenaf and glass fibre to develop hybrid composites with varying weight ratios on the low velocity impact response and the post-impact properties of the obtained composites. Four main process had been carried out in this study, which were the fabrication of composites, the low velocity impact testing, the dye penetrant evaluation on the impacted composites and the compression testing on the impacted samples after the dye penetrant evaluation. This research was motivated by the increasing demand for lightweight, cost-effective and environmentally friendly materials to be applied at an industrial level. In this paper, natural kenaf fibre was hybridized with synthetic glass fibre in an attempt to create an attractive material for the composite industries. The materials were fabricated in seven samples with varying weight percentage ratios of the fibres, while the glass fibre was used as the outermost layer for each formulation. A sample made entirely from kenaf fibre and another one entirely from glass fibre were also included for comparison. The formulation that demonstrated the best tensile performance – that with the weight percentage ratio of 25% kenaf fibre and 75% glass fibre – was then subjected to low velocity impact tests. Four impact energy levels of 10 J, 20 J, 30 J and 40 J were applied to study the propagation of impact in the composite with the optimum formulation. The closed curve on the graph plotting force versus displacement indicated the success of the specimen in absorbing the dissipated energy up to 40 J. The dye penetrant test was performed to investigate the damage area progression, and it revealed that a higher energy level will produce greater damage. Compression after impact tests indicated that the compression damage decreased as the impact energy was increased. Considering that the hybrid composite with the weight ratio of 25% kenaf fibre and 75% glass fibre approached the performance of the material made entirely from glass fibre, it may be concluded that it can be employed for product development in environmentally friendly technologies. Keywords: Kenaf, Glass, Hybrid composites, Low velocity impact, Compression after impact, Dye-penetrant test, Non-destructive testing
... It contains SiO 2 as major constitute (65 wt%) which imparts low thermal expansion and stable performance at elevated temperatures to the fibers 3 . Virgin S-glass fiber has properties such as density (2.49 g/cm 3 ) and stiffness (70-80 GPa) that are equivalent to pure aluminum, it's tensile strength (UTS 4700 MPa) fifteen times greater than heat-treated aluminum alloys such as AA6061-T6 (UTS 310 MPa) [4][5][6] . ...
... For instance, Pt-10%Ir has a young modulus of around 202 GPa, 28 MP-35N is 234 GPa (Fort Wayne Metals), 29 and typical glass fibers are ∼72 GPa. 30 Furthermore, the same waveguide for power delivery can also be utilized for optical data transfer between the implant and the external electronics within a much wider bandwidth than most other methods of signal telemetry. ...
Article
Neural electrodes and associated electronics are powered either through percutaneous wires or transcutaneous powering schemes with energy harvesting devices implanted underneath the skin. For electrodes implanted in the spinal cord and the brain stem that experience large displacements, wireless powering may be an option to eliminate device failure by the breakage of wires and the tethering of forces on the electrodes. We tested the feasibility of using optically clear polydimethylsiloxane (PDMS) as a waveguide to collect the light in a subcutaneous location and deliver to deeper regions inside the body, thereby replacing brittle metal wires tethered to the electrodes with PDMS-based optical waveguides that can transmit energy without being attached to the targeted electrode. We determined the attenuation of light along the PDMS waveguides as 0.36 ± 0.03 dB/cm and the transcutaneous light collection efficiency of cylindrical waveguides as 44% ± 11% by transmitting a laser beam through the thenar skin of human hands. We then implanted the waveguides in rats for a month to demonstrate the feasibility of optical transmission. The collection efficiency and longitudinal attenuation values reported here can help others design their own waveguides and make estimations of the waveguide cross-sectional area required to deliver sufficient power to a certain depth in tissue.
... Glass fibers are the most dominant fibers used in reinforcing polymers due to their low cost. Glass fibers are widely used in defence, aerospace, automotive, and other industry domains [36]. Proper orientation of continuous glass fibers provides the properties offered by steel with almost 75% less specific weight than aluminium [37] [38]. ...
Thesis
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The latest trends are encouraging the reinforcement of Fused Deposition Modeling (FDM) using several methods. Recently continuous fibers were taken into consideration due to their unique properties when integrated with FDM. Several manufacturers started giving notable attention for continuous fibers 3D (CF3D) printing. In this paper, an overview of FDM and its fiber reinforcement techniques is presented, focusing on the use of the three main fiber materials, Carbon, Glass and Kevlar fibers. Those techniques are presented together with the available commercial desktop CF3D printers. The review comprises an evaluation and comparison between the following CF3D printers: Mark II by Markforged, FiberTM by Desktop Metal and Composer by Anisoprint. The main objective of the paper is to introduce, assess and compare the available desktop CF3D printers.
... The inclusion of nearly 2-mol% Li 2 O in each glass composition was found to be necessary to reduce the viscosity sufficiently to enable reproducible forming of the 7 × 7 cm plates that were needed for solar performance testing. Although this compositional change represents a slight departure from current float glass compositions, 100 manufacture of similar glass compositions has been successfully trialled and demonstrated at commercial scale100 ...
Article
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For the solar energy industry to increase its competitiveness, there is a global drive to lower the cost of solar‐generated electricity. Photovoltaic (PV) module assembly is material‐demanding, and the cover glass constitutes a significant proportion of the cost. Currently, 3‐mm‐thick glass is the predominant cover material for PV modules, accounting for 10%–25% of the total cost. Here, we review the state‐of‐the‐art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re‐emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies and (iii) successful laboratory‐scale demonstration of proof of concept, with increases of 1%–6% in Isc and 1%–8% in Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints.
... 14 Nylon is used because of their high tensile strength, elasticity, luster, excellent scratch resistance, highly resistant to abrasion and chemicals. They are also not affected by insects, fungi, animals, and rots [15][16][17] and hence used for fishing purpose. Glass fibers, the utmost common reinforcement material for manufacturing polymer matrix composites, gained its way by their high tensile strength, high chemical resistance, and insulating properties. ...
Article
Full-text available
This paper involves the utilization of waste fishing nets as one of the reinforcements in the manufacturing of fumed silica coated composite partition sheets. Hybrid Fishing Net Reinforced Plastic (HFNRP) composite sheets developed by sandwiching various layers of used fishing net between the two glass fiber layers and in-situ coated with the AEROSIL ® 200 nano powder, were tested for mechanical properties. Appreciable values for mechanical properties were seen for all the HFNRP sheets; more pronounced when the number of fishing net layers was increased. On the contrary, the light transmission through the sheets decreases. The nylon content of the fishing nets in the sheets increased the linear thermal expansion with highest value of 2.01 inches/100 feet (0.168%). Moreover, water absorbing properties of the coated HFNRP sheets revealed to be moisture resistant due to the coating of polyester/nano powder resin mixture. Thermogravimetric Analysis and Differential Thermal Analysis revealed the mass change and phase change for the various manufactured specimens. The wear analysis with the pin on disk experiment revealed the wear resistance through the allied action of the flexible fishing net nylon and the friction resistant nano coating over the specimens. These, low cost and less weight composite sheets were successfully developed and implemented as the partition sheets for affordable buildings and fishing nets were efficiently reused.
... Despite this, Nahmias (1933) remarkably stated the presence of tridymite in devitrified glasses with 78% SiO 2 , 12% CaO and 10% Na 2 O. Later on, Garofalini and Miller (1986) showed that with an increased sodium content in silica glasses, the rate of tridymite formation significantly increases. Accordingly, a mixed type of glass waste can be categorized as soda-lime-silica (SLS) with different amounts of impurities, and possibly the devitrification was avoided during manufacturing to achieve pure glassy material by using annealing stage (Wallenberger and Bingham, 2010). To date, there has been no study on the effect of devitrified glass waste and the possible formation of tridymite and cristobalite on the geopolymerization process, despite the high dissolution rate of tridymite and cristobalite in alkaline conditions. ...
Article
The low solubility of glass powder is one of the important elements hindering the large volume recycling of glass waste (GW) in structural geopolymer materials. The current study aims to investigate an enhancement process of GW to be reused in improved performance geopolymer binders. The method relies on the devitrification of GW powder through heat treatment at below and above the transition temperature of quartz in order to develop new phases of tridymite formation. The devitrified glass waste (DGW) was incorporated in optimized combinations with metakaolin using an algorithmic mixture design approach of pre-targeted ratios of SiO2/Al2O3, Na2O/SiO2 and liquid/solid. Mixtures of raw GW and metakaolin were used as control geopolymers. Mechanical strengths of the developed binders were assessed up to 90 days of ambient curing. In addition to the X-ray diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR) used to characterize the formation of tridymite in DGW powder, comprehensive analysis, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and FTIR, was completed to inspect the microstructural change based on oxide ratios and DGW contents. Sustainability analysis was also performed to assess the energy consumption and CO2 emission of the produced geopolymer binders. The results indicated that the maximum tridymite formation occurred under 1-h heating at a temperature of 900 °C. The existence of higher tridymite content caused a significant increase in the compressive strengths of geopolymers made of 75% DGW compared to control mixtures with raw GW. The creation of more silanol (Si–OH) groups and generation of accelerated and greater degree of geopolymerization were shown as the outcomes of DGW in the geopolymer reaction process of binders.
... Polymer matrix composites using epoxy resins are commonly used for armor applications due to their high specific stiffness, strength, and capability to dissipate energy [1]. Epoxy resins provide a good balance of properties ranging from mechanical properties and environmental degradation resistance and offer ease of processability (favorable viscosity, pressures, and cure temperatures) and compatibility with a wide range of glass fiber sizing that allows tailoring of interphase properties. ...
Conference Paper
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Epoxy resin-based composite panels used for armors may be subjected to a wide range of operating temperatures (-55°C to 76°C) and high strain rates on the order of 103-104 s-1. Over the life cycle, various environmental factors also affect the resin properties and hence influence the performance of the composites. Therefore, it is critical to determine the stress-strain behavior of the epoxy resin over a wide range of strain rates and temperatures for accurate multi-scale modeling of composites and to investigate the influence of environmental aging on the resin properties. Additionally, the characterization of key mechanical properties such as yield stress, modulus, and energy absorption (i.e. area under the stress-strain curve) at varying temperatures and moisture can provide critical data to calculate the material operating limits. In this study, we characterize mechanical properties of neat epoxy resin, SC-15 (currently used in structural armor) and RDL-RDC using uniaxial compression testing. RDL-RDC, developed by Huntsman Corporation, has a glass transition temperature of ~ 120°C, compared to ~ 85°C of SC-15. A split Hopkinson pressure bar is used for high strain rate testing. Quasistatic testing is conducted using a screw-driven testing machine (Instron 4484) at 10-3 s-1 and 10-1 s-1 strain rates and varying temperatures. The yield stress is fit to a modified Eyring model over the varying strain rates at room temperature. For rapid investigation of resistance to environmental aging, accelerated aging tests are conducted by immersing the specimens in 100°C water for 48 hours. Specimens are conditioned in an environmental chamber at 76 °C and 88% RH until they reach equilibrium. Tests are then conducted at five different temperatures from 0°C to 95°C, and key mechanical properties are then plotted vs. temperature. The results presented are an important step towards developing a methodology to identify environmental operating conditions for composite ground vehicle applications.
... Nm/kg) [5,6], thus often used in high strain rate ballistic applications. S-glass composition (weight percent) consists of 60-67% SiO 2 , 23-25% Al 2 O 3 , and 8-12% MgO, and it can be categorized as MAS (Magnesium Aluminosilicate) glass [5,7,8]. In this study, the properties of S-glass are compared to silica consisting of 100% SiO 2 . ...
Article
Glass fibers are widely used as reinforcements in composites for applications ranging from lightweight and damage tolerant structures to protective materials providing high levels of energy absorption during ballistic impact. Understanding the atomistic origin of mechanical response and damage modes under various strain rate loading conditions is important to improve the properties of glass fibers. In this paper, molecular dynamics (MD) simulations with a reactive potential relate the composition of S-glass fiber to the mechanical properties and progressive damage mechanisms. Stress-strain response of Magnesium Aluminosilicate S-glass fiber using our newly developed Mg/Al/Si/O ReaxFF interatomic potential is predicted from 1e7/s to 1e15/s. Overall strain rate dependent modulus and strength data exhibit a characteristic S-shaped curve on a semi-log plot indicating strain rate dependent properties followed by a steep rise in properties at approximately 1e12/s to a strain rate-independent plateau. Detailed analysis of the atomic structure during high strain rate tensile loading provides insight into the dependency of properties on the rate of atomistic reconstruction, suggesting that the characteristic time-to-reconstruct is an important factor governing strain rate-dependent progressive damage. The origin of the higher modulus of S-glass over silica arises from electrostatic interactions associated with Al-O and Mg-O bonds in S-glass. Investigation on Al-O-Mg, Mg-BO/NBO interaction, and Al/Si-O ring structure indicates that the reconstruction of local structure leads to a more ductile-type response and progressive damage evolution in S-glass fiber than silica glass. In addition, we introduce a methodology to construct stress-strain response for low strain rates (1E-3/s) from a series of high strain rate loading to prescribed strain levels followed by stress-relaxation to an equilibrium stress level. The method is computationally efficient, and the results agree with the quasi-static modulus of both S-glass and silica.
... The boundary layer flow has been broadly deliberated in the literature and plays a vital role in fluid dynamics. The investigation of boundary-layer flowing past a horizontal plate had countless manufacturing implementations, such as food manufacturing, glass fibers production, manufacturing of rubber sheets, extrusion, metal spinning, wire drawing, and cooling of massive metallic plates such as an electrolyte [2][3][4] . Makinde and Onyejekwe 5 presented the numerical computations for the boundary-layer flowing model results in the stretching sheet with variable electrical conductivity and variable viscosity using a shooting technique and a sixth-order RK integration algorithm. ...
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Controlled incorporation of dopants into the structure of metal oxide catalysts can be used to fine-tune their topological, chemical, and electronic properties. Conventional preparation methods (co-precipitation and impregnation) tend to produce materials with a limited extent of chemical interaction between metal oxide and dopant, small pore volume, and disconnected pore structure. Here, we describe a combustion method to optimize both the porous structure of metal oxides and the chemical interaction with dopants. By exploiting the differences in melting points between metal oxide (MgO) and dopant (B), it is possible to create hierarchical mixed oxides with tailored chemical structure. As a model reaction, we have employed the aldol-condensation of acetaldehyde to crotyl alcohol, a key intermediate step in the conversion of bioethanol to 1,3-butadiene, to show the unique characteristics of these materials. The B-Mg mixed oxide prepared by combustion exhibits an order of magnitude higher in productivity of C4 compared to conventional MgO and B-MgO. We anticipate that our approach could be extended to the development of other dual oxides with open structure for unrestricted diffusion and enhanced chemical interaction of acid and basic metal oxides.
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Experimental investigation of the effect of strain rate and temperature on large inelastic deformation of an epoxy resin is presented. Uniaxial compression tests were conducted on DER 353 epoxy resin at strain rates ranging from 0.001 to 12,000/s. Experimental results showed significant rate sensitivity in yield stress, which increased from 85 MPa at 0.001/s to 220 MPa at 12,000/s strain rate. Thermal softening became more prominent as the strain rate was increased, resulting in complete absence of strain hardening at high strain rates. Rise in temperature under high strain rate, due to adiabatic heating, was estimated to increase above glass transition temperature (Tg ). A series of compression tests carried out at temperatures ranging from ambient to Tg + 80 °C showed yield stress vanishing at Tg . Above Tg , the epoxy became completely rubbery elastic at quasi-static loading rate. Epoxy became less sensitive to strain rate as the temperature was increased further above Tg . The strain rate and temperature dependent yield behavior of the epoxy resin is predicted using Ree–Eyring model.
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A large number of metallic glasses (MGs) with high mechanical and functional performance that cannot be achieved by traditional metals in various alloy systems have been developed. At the same time, people realized that micro- and nanoscale wires can improve properties and extend functionality of bulk materials. Therefore, intensive effort has been made to fabricate micro- and nanoscale MG wires, and study their mechanical and physical behavior to achieve high performance. This article reviews fabrication, properties and applications of the wires, and presents technical and theoretical challenges, which must be tackled to achieve high-performance MG wire devices and understand physical mechanisms of mechanical and functional behaviors of the wires.
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The elastic properties of quaternary glass-forming systems within the CaO–MgO–Al2O3–SiO2 composition were evaluated. Their compositions differed by not more than 3 mol% for each component from each other. After melting, the exact chemical compositions were determined using X-ray fluorescence, and the densities were measured by Archimedes method and pycnometer. This property and its dependency upon small variations in the composition are the main focuses of this paper. Experimental elastic properties such as Poisson’s ratio and Young’s modulus were calculated by measured ultrasound wave velocities (longitudinal and shear) at room temperature. Model calculations of the Poisson’s ratios were not in satisfying agreement with the measured results. The experimentally determined data of the Young’s modulus values ranging between 87 and 91 GPa were compared to different model calculations, which were mostly smaller than the measured ones, ranging—depending on the model—between 70 and 93 GPa. The effect of MgO was also studied by comparing the glasses with similar compositions without any MgO.
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The thermal properties of the quaternary glass-forming CaO–MgO–Al2O3–SiO2 system were evaluated. Different glass compositions with an expected liquidus temperature—the lowest temperature at which both the crystal phase and the melt are thermodynamically stable—below 1300 °C were melted from pure raw materials. Each oxide concentration did not deviate by more than ±3 mol% from that of the centre glass composition of 61.2 SiO2, 26.3 CaO, 8.6 Al2O3 and 3.8 MgO. Viscosity data and the liquidus temperatures were determined, as well as the exact compositions of the respective glasses by X-ray fluorescence. It was of special interest for this study, whether small compositional changes have a stronger influence on TLiq or T3. The T3-values, which are the temperatures attributed to a viscosity of 10³ dPa s—showed a much larger variation and are in the range from 1263 to 1363 °C. An exchange of the network formers Al2O3 or SiO2 by network modifiers CaO and MgO resulted in a decrease in viscosity. The effect of MgO was also shown by a comparison with glasses of similar compositions but without any MgO. The exchange between Al2O3 and SiO2 did not show a significant difference in viscosity whereas the substitution of CaO by MgO increased the viscosity. The liquidus temperature varied between 1137 and 1192 °C—less than expected for a composition close to an eutectic system.
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Fiber- reinforced shells manufactured by winding bands of fiber rovings and a revision of the basic problems connected with their design are addressed in the article. The importance of fiber type and matrix properties for the damage process of such laminar shells and for establishing criteria of their design is investigated. Particular attention is given to the mechanism of shearing of their matrix layers, which leads to delamination. Practical recommendations for the design and manufacture of wound shells are formulated.
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Bioactive glasses are able to chemically bond to hard and soft tissues and have been proposed and used for tissue regeneration in several dentistry and medical applications. However, the majority of bioactive glass compositions do not support prolonged or repeated heat treatments, since these procedures often result in uncontrolled crystallization, which usually degrade their mechanical properties and, in most instances, substantially diminish their bioactivity. Therefore, the manufacturing of 3D devices, fibers or scaffolds, which aim to expand the usage of these materials, is a challenging task. To overcome this phenomenon, a new bioactive glass composition was recently developed at the Vitreous Materials Laboratory (LaMaV—UFSCar, Brazil) and licensed to the start-up company VETRA. This new bioactive glass composition shows high stability against crystallization coupled with high bioactivity, which allows the development of bioactive fibers, meshes and other complex 3D shapes. In addition, this bioactive glass has an elevated bioactivity, is bioresorbable and flexible (in fiber form), which makes this glass a potential alternative for soft and hard tissue regeneration. In this article, we discuss this recent development and summarize the latest advances in testing the effectiveness of this new material in in vitro and in vivo tests. To date, the results indicate that this new glass composition presents a larger workability window, which allows the development of numerous medical devices. This feature combined with the high bioactivity of this new glass delivers a promising broad spectrum of applications as a material for tissue engineering.
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Fibrous reinforcements, specifically those derived from agricultural sources, instead of steel make concrete more sustainable and provide unique properties to structures. Organic, inorganic and metallic fibers have been extensively studied as reinforcement and as aggregates for concrete. Steel, glass and carbon in fibrous forms have been used as reinforcement along with concrete or as a separate structure to improve performance or buttress dilapidated structures. Although these traditional materials provide good improvement in properties, they are derived from non-renewable and unsustainable sources. Recent focus has been to use renewable and sustainable materials in concrete instead of the traditional materials such as glass, carbon and steel. A plethora of fibers and fibrous materials, especially those derived from agricultural residues, have the potential to be used in concrete and make concrete structure more sustainable and environmentally friendly. In addition to the different types of fibers, various forms of the same fibers have also been used as reinforcement. Fibers, fabrics, tubes, rods and other structures have been used as reinforcement. In this review, we summarize the various types of fibers used in concrete and discuss the potential of using biofibers derived from agricultural residues as reinforcement and aggregates in concrete. We have broadly grouped the fibers into eight categories and further divided into sub-groups depending on the form of the reinforcement. Major focus has been to cover literature on natural fibers and agricultural residue-based reinforcements. Advantages of using fibrous materials including increase in performance properties have been reviewed. Limitations of the reinforcements and approaches to overcome the limitations have also been discussed.
Chapter
This chapter gives the details of various synthetic fibres (both organic and inorganic such as glass, carbon, aramides, polyolefins, ceramic fibres, etc.) used to reinforce composite materials for conventional as well as very high-tech applications. Production and properties of these fibres and also the most common applications in fibre reinforced composites are included in this chapter.
Chapter
Most wood products include additives. They may be preservatives to protect the wood against biological degradation or against fire, coatings for protection or to give the wood a more favourable aesthetic appearance, non-wood materials to improve the performance of the product and overcome weaknesses in the wood material, or plastics in combinations with wood residues to create new types of wood–plastic combinations. The global wood industry is, for example the largest user of adhesives; about 80 % of all wood and wood-based products involve some form of bonding and 70 % of the total volume of adhesives produced is consumed in the woodworking industry. Wood can thus be regarded as a composite consisting of wood-based materials combined with other materials to form an aggregate material. An example is plywood, in which veneers are joined with adhesive to form a flat panel. Other types of wood composites include various board products, structural composite timber and, furniture and joinery components, all including some form of bonding with adhesive. This situation obviously influences the way in which we should relate to wood products and their environmental impacts. This chapter gives a state-of-the-art presentation of different additives currently being used in wood products. This information is necessary for further studies on the influence that these additives have on the service life and on environmental aspects, and the limitations which they may impose on the reuse, recycling and upgrading of wood products.
Conference Paper
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There is much consideration of roof selection as a protector of a building against the outside weather, such as lightweight, strong stiff, corrosion resistant and guarantee for the availability of products. Based on these considerations, glass fiber reinforced polymer (GFRP) roof is a roof which can fulfill the requirement. The objective of this research is to investigate the degradation of physical and mechanical properties of GFRP roof exposed in outside weather. This GFRP roof composite was produced using a sheet molding compound (SMC) supplied by PT Intec Persada, Tangerang, Indonesia. There are two kinds GFRP roofs evaluated in this research that are GFRP roof exposed within 7 years and new GFRP roof that has not been exposed. The GFRP roofs were cut manually for preparing the specimens for hardness test, tensile test, SEM and FTIR test. The results show that the GFRP roof exposed within 7 years had the degradation of properties compared to the new GFRP roof. The exposed GFRP roof had lower strength and hardness compared to the new GFRP roof. The SEM observation indicates that exposed GFRP roof had the debonding of fiber on the surface, and in contrast, there are no debonding of fiber in the new GFRP roof surface. It can be recommended that the exposed GFRP roof may be repaired to enhance its performance and can re-increase its properties using the coating.
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The present numerical study reports the chemically reacting boundary layer flow of a magnetohydrodynamic second‐grade fluid past a stretching sheet under the influence of internal heat generation or absorption with work done due to deformation in the presence of a porous medium. To distinguish the non‐Newtonian behaviour of the second‐grade fluid with those of Newtonian fluids, a very popularly known second‐grade fluid flow model is used. The fourth order momentum equation with four appropriate boundary conditions along with temperature and concentration equations governing the second‐grade fluid flow are coupled and highly nonlinear in nature. Well‐established similarity transformations are efficiently used to reduce the dimensional flow equations into a set of nondimensional ordinary differential equations with the necessary conditions. The standard bvp4c MATLAB solver is effectively used to solve the fluid flow equations to get the numerical solutions in terms of velocity, temperature, and concentration fields. Numerical results are obtained for a different set of physical parameters and their behaviour is described through graphs and tables. The viscoelastic parameter enhances the velocity field whereas the magnetic and porous parameters suppress the velocity field in the flow region. The temperature field is magnified for increasing values of the heat source/sink parameter. However, from the present numerical study, it is noticed that the flow of heat occurs from sheet to the surrounding ambient fluid. Before concluding the considered problem, our results are validated with previous results and are found to be in good agreement.
Thesis
An increasing demand for materials used for stab protection has been expressed to provide more protective, flexibility and lightweight. Researchers have mainly focused on studies about stab resistance of soft body armour based upon technical textile fibres and 2D fabrics. However, the soft protective materials based on 3D fabrics have been rarely study in recent research works, especially those revealing that 3D woven architectures can play a decisive role during stab impact. 3D warp interlock fabrics (3DWIFs) can be used in a soft vest for anti-stab applications. The overall aim of this current research has been oriented to explore different design of 3DWIFs that provide the more efficient protective solution. Hence, this thesis has been concentrated on both the manufacturing process parameters and the resulted product parameters of the 3DWIFs made with HMWPE yarns. The production process parameters have been studied to optimize the manufacturing and the mechanical properties of 3DWIFs. The product parameters of 3DWIFs have been investigated to find the optimized combination for the best protective resistance against stabbing. The four main categories of 3D warp interlock fabrics architectures as : A/T, A/L, O/T, and O/L, were woven by twisted high molecular weight polyethylene (HMWPE) yarns. The mechanical characteristics of 3DWIFs were systematically tested and compared. Besides, a dedicated experimental study has been performed on 3DWIFs submitted to low-speed impact, including single-stab and double-stab properties in terms of depth of penetration and trauma. The double-pass stabbing tests are complementary to single-pass stabbing tests. It was experimentally concluded that the orthogonal/through-the-thickness interlock fabric has a good stab resistance. Meanwhile, the links among stab resistance, physical properties, and mechanical properties of 3DWIFs have been analysed.
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In recent years, glass fiber-reinforced epoxy composites have been proven to be a promising material for use in fabricating insulator core rods for high-voltage transmission lines. Composite insulator core rods are reportedly degrading during its application due to poor interfacial bonding, brittle fracture, stress corrosion cracking, water absorption, and decay-like fracture. These key factors have affected their mechanical and electrical insulation properties during application. However, this review summarizes the effects of glass fibers, such as E-glass and electrical corrosion resistance glass fiber on the corrosion, mechanical, and electrical properties of epoxy composites for composite insulator core rods. Further, the authors concluded the review with advancement, challenges, and recommendations for future improvement of epoxy composites as a mechanical load-bearing and insulation component material in high-voltage composite insulators. As such, the review offers an intuition into the advancement and selection of glass fiber-reinforced epoxy composite materials for core rods. More so, the review will also give way for further research on insulator core rods development for high-voltage transmission lines.
Chapter
The fiber reinforced polymer composites (FRPC) are being widely used in several advanced engineering structures ranging from civil infrastructure to aircraft, spacecraft, ships, cars, sports goods and in many other outdoor and household applications. The major advantage is its high specific strength, stiffness, and durability leading to sustainable applications. However, the knowledge of the basic constituents, their roles, and failure mechanism are essential to properly understand the behaviour of the composites for design and manufacturing of FRPC components and structures. This chapter will provide an introduction of the FRPC, a brief history of FRPC and its constituents such as fibers and matrices. More detailed information on types, manufacturing, and classification of glass, carbon, and aramid fibers will also be provided. Similarly, descriptions on various polymer matrices such as epoxy resins, vinyl ester, phenolic resins, polyester resins, and polyurethane, and also emerging resins for special applications will be furnished. Different classes of FRPCs with their typical characteristics have been discussed. This chapter further describes the fracture failure mechanism of FRPCs from mechanics or fracture mechanics approach indicating the existing research gaps in different sections.
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Crystallization, mechanical properties and workability are all important for commercialization and optimization of silicate glass compositions. However, the inter‐relations of these properties as a function of glass composition have received little investigation. Soda‐lime‐silica glasses with Na2O‐MgO‐CaO‐Al2O3‐SiO2 compositions relevant to commercial glass manufacture were experimentally studied and multiple liquidus temperature and viscosity models were used to complement the experimental results. Liquidus temperatures of the fabricated glasses were measured by the temperature gradient technique, and Rietveld refinements were applied to X‐Ray powder diffraction (XRD) data for devitrified glasses, enabling quantitative determination of the crystalline and amorphous fractions and the nature of the crystals. Structural properties were investigated by Raman spectroscopy. Acoustic echography, micro‐Vicker’s indentation and single‐edge notched bend testing methods were used to measure Young’s moduli, hardness and fracture toughness, respectively. It is shown that it is possible to design lower‐melting soda‐lime‐silica glass compositions without compromising their mechanical and crystallization properties. Unlike Young’s modulus, brittleness is highly responsive to the composition in soda‐lime‐silica glasses, and notably low brittleness values can be obtained in glasses with compositions in the wollastonite primary phase field: an effect that is more pronounced in the silica primary phase field. The measured bulk crystal fractions of the glasses subjected to devitrification at the lowest possible industrial conditioning temperatures, indicate that soda‐lime‐silica glass melts can be conditioned close to their liquidus temperatures within the compositional ranges of the primary phase fields of cristobalite, wollastonite or their combinations.
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In this paper, we discussed the fiber spinnability and mixed alkaline earth effect in the aluminosilicate glasses with MgO replaced by CaO. The high-temperature viscosity, dilatometric and DSC tests were applied. Results show that Kfib shows the opposite results to that from the graphical map of (m:D), while the ΔT only picks one glass sample for fiberizing. The mixed alkaline earth effect manifests itself as minima in viscosity, and characteristic temperatures, but maxima in fragility, thermal expansion, which are related to the increased entropy, the loose network, and weak bonds, not the network connectivity. The lower values for Mg end-member would be attributed to the higher field strength that would attract the nearest oxygen and cause more disturbance to the glass structure. The free volume is not related to the mixed effects in the viscosity and characteristic temperatures but should have a relationship with the melt strength index.
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The effect of raising and lowering the temperature on the tensile properties of cristobalite spherical particle‐filled epoxy resin (CPTCL/EP) was investigated, and the fabrication of cristobalite fiber and its fiber‐reinforced plastic (FRP) was attempted. For the CPTCL/EP, the process of raising the temperature above the temperature at which the coefficient of thermal expansion of cristobalite suddenly changes (220°C) and then lowering the temperature to room temperature degraded the matrix and caused tensile residual stress in the matrix; however, interfacial adhesion between the matrix and filler improved. In other words, the tensile strength of CPTCL/EP was not reduced by this process, but rather improved. In contrast, the tensile strength of cristobalite fiber‐filled EP (CFIBER/EP) was significantly lower than the theoretical value owing to cracks in the fiber caused by dunting during fabrication of the fiber. Thus, the fabrication method needs to be further improved.
Article
As an application of composite science in the marine industry, the present paper deals with the multi-objective optimal structural design of a superstructure composite sandwich panel based on the first-order shear deformation laminated plate theory (FSDT). Several parameters including the type of fiber, matrix and core material, the amount of reinforcement, the core, lamina and laminate thickness, the laminate arrangement (stacking sequence) and the laminate construction are considered as the design parameters. A novel Multi-Objective Niching Memetic Particle Swarm Optimization (MONMPSO) algorithm is proposed and its performance is evaluated using the well-known non-dominated sorting genetic algorithm (NSGA-II). The results show that the proposed MONMPSO algorithm has a better performance in comparison to the NSGA-II algorithm in extracting the Pareto front pattern. Based on the numerical results, many useful structural rules for designing a composite sandwich panel under the out of plane pressure and buckling load have been deduced.
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Selective Laser Sintering (SLS) of ceramic powders is studied in order to understand how the initial material properties and the process conditions affect the degree of sintering/melting and the mechanical properties of the sintered material. Unimodal powder samples of different narrow particle size distributions between 16 and 184 μm were sintered with a 40 W CO2 laser, using laser scan speeds of either 50 or 100 mm s-1 and, in both cases, a scanning energy of 160 J m-1. The sintered material was studied by means of optical and SEM microphotography and characterized in terms of bulk density and tensile strength. The Rumpf approach to relate interparticle forces to the strength of powder agglomerates was used in this work to estimate the average strength of the sintered interparticle contacts starting from the tensile strength of specimens. In turn, the average strength of the neck contact was used to estimate the size of the neck of fused material between two sintered particles. These data coupled with the Frenkel model for particle sintering allowed an estimate of the sintering temperature for the different experimental conditions tested. The temperatures found are consistent with the glass transition temperature of the material used. The effect of particle size and scanning speed is assessed and discussed.
Article
This paper presented the cantilever beam experiments and the method for creep in chemically bonded ceramics reinforced with glass, carbon, and basalt unidirectional fibers. The ceramic composite samples were fabricated by mixing wollastonite powder and phosphoric acid, through the resonant acoustic mixing technique. The reinforced fibers were added via pultrusion process. The manufactured materials were exposed to high temperature creep tests at 600, 800 and 1000℃, with an annealing time of 1 h, all in air environment. Some examples of real large-scale structures made manually by a company were also included. In order to understand the microstructure, X-ray diffraction and scanning electron microscopy analysis were included. The presented method is simple and can be used in any inorganic ceramic slurry types, such as geopolymers, phosphate cements, clay-based materials, or Portland cement composites. The sample response in high temperature creep experiments was analyzed with a new but very simple technique, and modeled using finite element analysis over all compositions. Results revealed that fibers have a significant effect on the composite creep when compared to the ceramic without reinforcement, and particularly carbon fibers showed a quite interested effect in reducing the creep effects. Results show the limit of the materials under conditions typically found in fires and other extreme environments.
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During previous century, automotive industry indicated a significant improvement and becoming one of the most important parts of human life today. Glass, which was initially used for the protection of driver and passengers from outside effects, has been an important part of most researches and new properties have been added, thus its usage fields have enlarged. Moreover, through new production technologies, other materials with glassy properties have become an inevitable part of automotive industry. In the present study, the state of glass and glassy materials in automotive industry from past to present time is mentioned with some examples on their applications and developments.
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Glass fiber lebih sering digunakan daripada polyethylene fiber sebagai komponen FRC dalam dunia kedokteran gigi. Glass fiber dental di Indonesia tersedia dalam jumlah terbatas dan memiliki harga yang relatif mahal. Tujuan dari penelitian ini adalah untuk memeriksa komposisi dari E-glass fiber dental dan glass fiber non dental menggunakan teknik XRF sehingga dapat ditentukan tipe dari masing-masing glass fiber non dental. Sampel terdiri dari 10 g E-glass fiber dental, 10 g fiberglass mats, 10 g fiberglass roving dan 10 g woven roving. Masing-masing sampel dihaluskan, selanjutnya dianalisa dengan dengan menggunakan X-Ray Fluorescence Spectrometer (XRF). Hasil analisa XRF sampel menunjukkan kandungan oksida terbesar pada E-glass fiber dental adalah SiO2 (45,47%), CaO (38,49%) dan Al2O3 (12,11%). Kandungan oksida terbesar pada fiberglass mats adalah SiO2 (56,88%), CaO (16,24%) dan Na2O (12,91%) demikian pula dengan woven roving yaitu SiO2 (55,86%), CaO (18,71%) dan Na2O (11,80%). Sedangkan fiberglass roving menunjukkan kandungan oksida terbesar antara lain SiO2 (52,56%), ZrO2 (14,64%) dan CaO (10,03%). Hal tersebut menunjukkan bahwa komposisi kandungan oksida pada sampel memiliki kemiripan dengan persentase yang berbeda. Berdasarkan pada analisis XRF disimpulkan bahwa glass fiber non dental jenis fiberglass mats dan woven roving mengarah ke tipe C-glass dan fiberglass roving mengarah ke tipe AR-glass.
Chapter
One of the challenges that architects and designers are confronted with in contemporary contexts is the need to address an ethical responsibility towards the health of the environment through understanding the energetic processes embedded in materials and their compositions. A scientific explanation of material fundamentals, including chemistry, physical structure, and embodied energy, provides the greatest insight to material property performance values and relative environmental impacts. This information aids architects in making informed decisions about building materials in the design process. This chapter addresses the book topic of reusable and sustainable building materials through the position that all matter is a form of energy, just as living systems are the transmutation of matter and energy. The seven major material groups, which include natural materials, non-technical ceramics, technical ceramics, metals, polymers, foams and elastomers, and composites, are presented with examples and applications discussed.
Article
In this second of the two-part paper, the two-level parametrically-upscaled continuum damage mechanics models (PUCDM-1 and PUCDM-2) developed in the first part Xiao et al. (2022) are applied for multiscale analysis of plain weave composite structures. The material damage response in the intra-yarn unidirectional microstructures and the woven yarn-matrix mesostructures are respectively represented by level-1 and level-2 PUCDM models. The models bridge material length scales through explicit functions of the lower-scale morphological descriptors (representative aggregated micro/mesostructural parameters or RAMPs) and material properties (Xmat) with high computational efficiency. The paper focuses on model validation with experiments and parametric studies. The model is validated with observations from tensile tests on an hourglass-shaped specimen with good agreement at multiple scales. The validated PUCDM model is then employed for the analysis of multiscale deformation and damage mechanisms in single-edge notched bending (SENB) tests on woven composite beams. Parametric studies are performed to investigate the effect of lower-scale morphology and material properties on the structural damage response of the woven composite beams.
Article
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Composite materials were created for usage as reinforcement and to protect the building envelope based on today’s global conditions such as climate change. Composite materials were manufactured using phenol-formaldehyde resin (case of resol) as a matrix, carbon fiber as reinforcement (7.5% v/v ), and perlite (10% w/w ) as a low thermal conductivity component, to combine high mechanical properties with good heat resistance and good thermal insulation properties. The structure of these new materials was examined through scanning electron microscopy (SEM) and elemental analysis (SEM-EDS). The addition of perlite (10% w/w ) in the resite matrix (without fibers) increased the flexural and shear strength of the composite materials. On the other hand, the composite materials with fiber reinforcement show that the perlite reduces the flexural and shear strength due to the additional interfaces which were created. During heat treatment at 473 K, carbon fibers had the smallest weight loss followed by perlite while the resite matrix (i.e., the cured resol) shows the greatest weight loss. It is noted that the role of perlite is to stabilize the mass of the resite matrix during heat treatment. The composite material with carbon fibers and perlite is a heat-resistant material with only 2% weight loss at 473 K for 1 hour and shows a low coefficient of thermal conductivity, making it a new material in the direction of heat-insulating materials.
Thesis
Le réchauffement climatique dû à l’augmentation des émissions de gaz à effet de serre constitue l’une des problématiques majeures actuelles. Dans ce contexte, le stockage du CO2 dans des réservoirs géologiques se présente comme un moyen susceptible de limiter les conséquences de ces émissions sur l’environnement. Pour des raisons sécuritaires, cette méthode de gestion nécessite une surveillance continue des réservoirs de stockage à l’aide de capteur IR pouvant descendre dans les puits. L’application de cette technologie nécessite également de connaître le comportement du CO2 lors des différentes étapes de stockage, notamment lorsqu’il est dans son état supercritique. C’est pourquoi la microfluidique est actuellement utilisée afin de simuler et comprendre les phénomènes liés à l’injection et au stockage du CO2 sous forme supercritique. La mise en œuvre d’une telle approche requiert : (i) le développement de nouvelles solutions compactes pour la surveillance in situ des réservoirs en continu pour sécuriser les sites de stockage et; (ii) la bonne compréhension du comportement du CO2 lors des différentes étapes de stockage.Le premier axe de recherche consiste à synthétiser des matériaux vitreux afin d’optimiser l’efficacité d’un capteur optique de CO2 pour la surveillance des sites de stockage en aquifère salin et susceptible de détecter d’autres gaz, tels le méthane ou le monoxyde de carbone. Le capteur doit pouvoir être déployé en profondeur et capable de détecter des concentrations inférieures à 1000 ppmv pour repérer rapidement d’éventuelles fuites. Les verres de chalcogénures dopés avec des ions de terres rares spécifiques, peuvent produire une luminescence qui peut ensuite être utilisée pour détecter les signatures infrarouges de toutes les molécules possédant des bandes d'absorption dans la région spectrale 3-5 µm. Les compositions vitreuses Ga5Ge20Sb10(Se,S)65 (%mol.) dopées Pr3+ et Dy3+ ont été développées en vue de réaliser un capteur environnemental de CO2. Le potentiel de ces matériaux pour la multidétection de gaz (CO2, CH4 et CO) a également été exploré.Les systèmes microfluidiques HP/HT actuels ne permettent pas de coupler simultanément la spectroscopie infrarouge et Raman à ces dispositifs. Ce problème est dû à l’utilisation du verre Pyrex associé au wafer de silicium pour la fabrication des microréacteurs. C’est pourquoi le deuxième axe de recherche développé au cours de cette thèse vise à explorer différents systèmes vitreux pour trouver une alternative au Pyrex. Le verre en question doit présenter le meilleur compromis entre les propriétés optiques, thermomécaniques et électriques visées. Ainsi, des verres à base de GeO2 ont été développés pour répondre aux spécifications attendues, telle que le procédé de collage anodique utilisé pour fixer le verre au wafer de silicium. La composition vitreuse retenue pour les tests est 70GeO2-15Al2O3-10La2O3-5Na2O (%mol.).
Article
Comparative studies of the impregnability of high-strength and basalt fibers, treated and untreated by emulsions of film-formers, by epoxy binders with different curing agents were conducted. Differences in the surface treatment of high-strength and basalt fibers were found by determining the impregnation along the height of capillary rise of the binder. The effect of surface treatment on the change in strength of the tested filaments and microplastics based on them was determined.
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