Volume Fraction Of Glass Research Articles

Nacreous Glass Composites with Superior Performance Engineered through Mechanical Vibration and Silanization

AbstractBioinspiration offers alternative solutions to overcome the inherent drawbacks of glass, such as low fracture toughness, strength, and impact resistance. Synthetic composites inspired by natural materials, such as nacre, have been recently introduced as an alternative to glasses. However, these have all suffered from trade‐offs between rigidity, optical clarity, fabrication scalability, and complexity. Here, two wave‐based fabrication techniques are presented to create a nacreous structure from glass flakes and polymethyl methacrylate. The glass's surface energy is controlled by adjusting the silane coverage on the glass surface, enabling high levels of structural compactness, mechanical properties, and optical clarity. The scalable glass composite, with a ≈60% glass volume fraction, possesses strength, fracture toughness, and impact resistance values, outperforming annealed glass by 4300%, 350%, and 400%, respectively. It also has a haze level of ≈18%, almost 60% less than that of the similar centrifuged‐based glass composite. This composite is proposed as a potential glass alternative in diverse applications.

A two-phase analysis of the use of water-aluminum nanofluid in a solar still with a layer of phase change materials

This study employed the finite element method to simulate a solar still three-dimensionally. Aluminum nanoparticles were used in the still's tank, at the bottom of which was a layer of the N-auxin Phase Change Material (PCM). The variables of the problem included the degree of solar radiation for 12 different hours a day, the 10–45˚ angle of the front glass plate of the still, and the ambient temperature ranging from 293˚K to 330˚K. The effects of these variables on the air temperature, glass, PCM, and PCM volume fraction were examined. A two-phase method was used to analyze the nanofluid in the tank. The results showed that solar radiation generally had the highest effect on the maximum PCM temperature, maximum air temperature, and PCM volume fraction. However, the drop in the ambient temperature had the maximum impact on the maximum glass temperature. The PCM inside the solar still made the maximum air temperature slightly higher in the evenings than in the mornings. As a result, the maximum glass temperature could reach 330˚K at the ambient temperature of 330˚K and maximum solar radiation. In the last hours of the study, a decline in the angle of the solar still's front plate reduced the volume fraction of the molten PCM. Besides, at the 10˚ angle of the still's front plate, a drop in the outside temperature led the PCM to freeze faster.

Influence of adding steel – glass – polypropylene fibers on the strength and flexural behaviour of hybrid fiber reinforced concrete

This experimental research investigates the strength and load deflection characteristics of hybrid fiber reinforced concrete. Two or more types of fibers are combined to improve the overall properties of concrete. Grade of concrete chosen for study is M40 and the specimens were incorporated with 0.75% volume fraction of Steel, Glass and polypropylene fibers in equal proportions and in different combinations. This study primarily focused on compressive strength, split tensile strength and flexural tensile strength of composite with two types of fiber combinations. Results were compared with non-fibrous control concrete and strength effectiveness was observed to be more in Steel- Polypropylene fibers combination. Negative results were produced by Glass- polypropylene hybrid fiber composites. Based on the best strength results reinforced concrete beam specimen is made with Steel – polypropylene hybrid fiber combinations as a secondary reinforcement and it is tested under flexural loading conditions. Load deflection behaviour and crack studies were carried out on tested beam specimens. Finally experimental results were compared with Finite element software results and close agreement was observed between them.

A Statistical Analysis on Tensile behaviour of Single Edge Notched Jute Hybrid Composites

In this work, a statistical model was developed using Taguchi technique to study the factors influencing the tensile strength of single edge notched jute hybrid composites. Standard uniaxial tensile tests were conducted to evaluate tensile strength of single edge notched jute hybrid composite specimens, with different fiber orientations, glass volume fractions and notch sizes, in accordance with ASTM D3039 standards. It is observed that as glass volume fraction increases, tensile strength increases. As notch size increases, tensile strength decreases. The tensile strengths of specimens in fiber direction (0°/90°) were higher than those in off fiber direction (±45°). The forecast model indicates that the major parameters that impact the tensile strength were glass volume fraction and fiber orientation. Notch size had lesser impact on tensile strength. The optimum value of the tensile strength is observed for specimen with 0/90 fiber orientation, 45% glass volume fraction, 2mm notch size and from the confirmation test, the model results were observed to be near to the experimental values.

Experimental investigation on mechanical properties and free vibration characteristics of epoxy‐based glass/flax laminates

AbstractIn the present study, an attempt is made to replace the synthetic glass fiber used in the FRP structures in terms of natural flax fibers without much sacrifice on static and dynamic stability of the structure. Three types of glass/flax hybrid composite laminates were prepared with different fiber volume fraction of glass and flax fibers. For better understanding purpose, a dedicated glass and dedicated flax laminates were also fabricated. All the laminates were fabricated by vacuum bag molding method with uniform laminate thickness. The mechanical properties of the fabricated laminates, such as tensile strength and flexural strength, were evaluated in accordance with ASTM standards. The impulse excitation technique was used to assess the free vibration characteristics of glass/flax laminates such as modal frequency and material damping. Based on experimentally evaluated mechanical and vibration characteristics a suitable fiber volume fraction for the preferred laminate thickness was suggested to achieve optimum static and dynamic stability.

Decoupling Microstructural and Residual Stress Effects on Glass-Ceramic Toughening

Barium disilicate (BaO.2SiO 2 = BS2) is one of the very few stoichiometric glasses that allows for accurate control of the desired microstructure via thermal treatment, making it a (scarcely studied) model system for microstructure-property studies. Here, we performed a systematic research work on the variation in hardness, elastic modulus, fracture strength, and toughness as a function of the crystalline volumetric fraction, crystal size, and residual stresses in BS2 glass-ceramics (GC). These microstructural features were independently modified; the average crystal diameter varied from 5 to 100 μm and the crystallized volumetric fraction from 0 to 68%. The internal residual stresses in the crystals, are tensile in this system . Samples with an average spherulite size above 30 µm showed spontaneously fractured crystals due to the residual stresses. The samples with 5 and 10 µm spherulites have not cracked because the spherulites have a high volume fraction of residual glass (74%) and moderate internal stresses (40-70 GPa). The fracture toughness, K IC , increased with the spherulite size and volume fraction. However, the residual glass inside the spherulites rendered crack bowing, bridging, and trapping ineffective. The variation of K IC with the crystallized volume fraction is similar for GCs with different crystal sizes. Also, a comparison with a lithium silicate glass-ceramic showing compressive residual stresses yielded similar results. These combined findings indicate that the crystallization of a tougher phase is the crucial parameter controlling fracture toughness in these materials. The results with this model material can be extended to design novel strong and tough glass-ceramics.

Design, Analysis and Manufacturing Polymer Fiber Reinforced Composite Helical Spring

In this work it had been focused on the possibility of replacement of steel spring in suspension system by fiber reinforced polymer composite that is responsible for light weight of spring which leads to reduces the weight of vehicle and improve fuel efficiency. This type of spring used in motor cycles, light weight vehicle. The design will be simulated by ANSYS workbench. Then, E-Glass fiber has been used to fabricate helical compression spring of 40% fiber volume fraction of glass. with polyester resin. The deflection of glass reinforced composite spring is more than steel spring but within permissible limit. weight of composite spring is reduced by 57% than of steel.

Mechanical properties obtained by nanoindentation of sintered zircon–glass matrix composites

This study was undertaken to determine the effect of zircon content and firing temperature on the hardness and indentation modulus of zircon–glass composites obtained by sintering. A standard non-devitrified borosilicate glass (SRM 717a) powder and an industrial micrometric zircon powder were used to prepare mixtures with a zircon volume/solids volume between 0 and 0.63, by the wet method. The values of these mechanical properties were determined by nanoindentation and related to the most important microstructural characteristics of the composites, such as porosity, zircon volume fraction, glass volume fraction, and average zircon grain size. Composite mechanical performance was interpreted and determined by statistically analysing the results of a large number of indentations using two maximum loads. An empirical model was developed that describes the effect of these microstructural characteristics on composite hardness and modulus of indentation. Composites of high hardness (11.3 ± 2.5 GPa) and low porosity (ε = 0.07) were obtained at 1100 °C from a mixture with a zircon volume/solids volume of 0.43.

Vibration-Damping Factor of Glass/Kenaf/Polyester Hybrid Composite

The study of vibration-damping factor on unsaturated polyester resin reinforced glass and kenaf fiber has been performed. Two variations of glass and kenaf fibers were made based on fiber volume fraction (Vf) and ratio of glass to kenaf fiber at Vf of 25 %. The measurement of the samples was to obtain the value of the vibration-damping factor and the elastic modulus. The result shows that the vibration-damping factor decreases proportionally to the addition of fiber. Increased stiffness is evidenced by an increase in elastic modulus along with an increase in fiber content. According ratio of glass to kenaf fiber, the vibration-damping factor decreases proportionally with the increasing of glass fiber content. Increased kenaf fiber content causes an increase in vibration-damping factor, a decrease in elastic modulus, and lead to decreased in stiffness of the hybrid composite.

Thermal Diffusivity and Thermal Conductivity of Dispersed Glass Sphere Composites Over a Range of Volume Fractions

Glass spheres are often used as filler materials for composites. Comparatively few articles in the literature have been devoted to the measurement or modelling of thermal properties of composites containing glass spheres, and there does not appear to be any reported data on the measurement of thermal diffusivities over a range of filler volume fractions. In this study, the thermal diffusivities of guar-gel/glass sphere composites were measured using a transient comparative method. The addition of the glass beads to the gel increased the thermal diffusivity of the composite, more than doubling the thermal diffusivity of the composite relative to the diffusivity of the gel at the maximum glass volume fraction of approximately 0.57. Thermal conductivities of the composites were derived from the thermal diffusivity measurements, measured densities and estimated specific heat capacities of the composites. Two approaches to modelling the effective thermal diffusivity were considered.

Numerical and Experimental Investigation on I-type Damage Evolution in Glass Fiber Reinforced Laminates Subjected to Quasi Static Loading

Glass fiber reinforced polymer composites has become more popular material used in aerospace and marine structural applications due to their specific strength and anti-corrosion properties. The present work discusses the numerical and experimental investigation on I-type damage evaluation in glass fiber reinforced laminates under quasi-static loading is presented. Three volume fraction of glass and resin (40/60, 50/50 and 60/40) plies were selected for both numerical and experimental damage analysis. The damage analysis was conducted for double cantilever beam as per ASTM standard using a universal testing machine. The J-integral method of numerical investigation carried out by virtual crack closure technique and cohesive zone modelling. The fracture toughness has increased with the resin content and dependent on the ductility caused at the crack tip due to the plastic zone around the crack tip. The numerical results were found to possess good agreement with the experimental values. Cite this Article Nikhil Rangaswamy, Shivakumar S, Kallol Anupama N. Numerical and Experimental Investigation on I-Type Damage Evolution in Glass Fiber Reinforced Laminates Subjected to Quasi Static Loading. Emerging Trends in Chemical Engineering. 2017; 4(3): 27–33p.

Quasi- static indentation properties of damaged glass/epoxy composite laminates repaired by the application of intra-ply hybrid patches

The main objective of this paper is to investigate the effect of intra-ply hybrid patches based on glass and Kevlar woven fabrics on the local bending response of adhesive bonded external patch repairs in damaged glass/epoxy composite laminates. In intra ply hybrid patches glass and Kevlar fibre reinforcements are combined in the same layer. The intention, in using these hybrid patches, is to combine the excellent mechanical properties of glass fiber as a brittle reinforcement with the superior high elongation to failure property of Kevlar fiber as a ductile reinforcement. Five different kinds of plain weave woven fabrics with different ratios between glass and Kevlar fibers (100/0, 75/25, 50/50, 25/75 and 0/100) were used as the external patches. The undamaged virgin specimens were taken as a reference for the comparison of residual mechanical properties. Multiple quasi-static indentation tests were carried out on repaired glass/epoxy specimens, and their ultimate indentation load, stiffness and permanent deformation were estimated. Failure mechanisms of repaired glass/epoxy specimens under indentation loads were investigated using online Acoustic Emission (AE) monitoring technique. The indentation loads required for the occurrence of various failure modes were measured to illustrate the chronology of progression of different damage modes with increasing load and the kinetics of the various damage modes individually defined in real time. The use of different hybrid patches had a significant effect on the local bending response of the repaired glass/epoxy specimens. In practice, specimens repaired with patches including equal volume fraction of glass and Kevlar fibers presented a more favorable indentation response than virgin ones and other repaired specimens by exhibiting balanced mechanical properties (i.e., high deflection to ultimate failure associated with superior patch-parent laminate bond strength).

In-situ synthesis of novel Al-Fe-Si metallic glass coating by arc spraying

A novel in situ forming Al-Fe-Si metallic glass coating comprising partial nanoscale particles embedded in Al-based metallic glass matrix was synthesized by arc spraying process. The coating is adhering well and very compact with porosity of less than 2%. The volume fraction of metallic glass is 74.9% approximately. The onset crystallization temperature of the coating is 359 °C. The coating exhibits a high hardness (H = 4.25 GPa) and reduced Young's modulus (E = 235 GPa), together with good H/E, H2/2E and elastic recovery (η value). Dry sliding wear testing of the coating shows that the relative wear resistance of the coating is about 2.9 times that of the Al-6061 alloy under the same testing conditions. The dominating wear mechanism of the coating is a combination of brittle fracture delamination coupled with oxidative wear under dry sliding conditions. Meanwhile, potentiodynamic studies of the metallic glass coating in 0.6 M NaCl solution displays better corrosion resistance than that of Al alloyed coatings and EQ70 marine steel. In addition, the reasons actualizing the enhancement of the mechanical properties and corrosion resistance were elucidated.

Effect of patch hybridization on the tensile behavior of patch repaired glass/epoxy composite laminates using acoustic emission monitoring

This paper investigates the tensile response of damaged glass/epoxy composite laminates repaired using hybrid external patches. Hybrid external patches based on glass and Kevlar woven fabrics bonded on both faces of the damaged parent laminate were considered. Five different kinds of plain weave woven fabrics with a different ratio between glass and Kevlar fibers (100/0, 75/25, 50/50, 25/75 and 0/100) were used as the external patches. The intention of using these hybrid patches was to combine the excellent tensile stiffness of Kevlar fiber with the superior resin adhesion property of glass fiber. The virgin and damaged specimens were taken as the reference specimens for comparison of residual mechanical properties and damage mechanisms. Damage evolution and the failure progression of the repaired glass/epoxy specimens were monitored using real-time Acoustic Emission (AE) monitoring technique. The Acoustic Emission (AE) results depict different damage profiles and link them with mechanical test results to reveal the load to a change in failure mechanisms during mechanical loading concerning the influence of each hybrid patches on the performance of repaired glass/epoxy specimens. Good correlation of the acoustic emission results with the photographic images of fractured specimens was obtained. Specimens repaired with the equal volume fraction of glass and Kevlar fibers in the external patches presented the most favorable residual tensile response by effectively releasing the stress concentration in the damaged area.

Effect of patch hybridization on the compression behavior of patch repaired glass/epoxy composite laminates using acoustic emission monitoring

This article investigates the compressive response of damaged glass/epoxy composite laminates repaired using hybrid external patches. Hybrid external patches based on glass and Kevlar woven fabrics bonded on both faces of the damaged parent laminate were considered. Five different kinds of plain weave woven fabrics with a different ratio between glass and Kevlar fibers (100/0, 75/25, 50/50, 25/75, and 0/100) were used as the external patches. The intention of using these hybrid patches is to build up a patch of optimum stiffness that facilitate to restrict the critical adhesive or cohesive failure on the joints unlike high stiff glass fibers or extensive fiber micro‐buckling of the external patches unlike low stiff Kevlar fibers under compression loading and consequently to produce repaired laminates with a strain to failure and residual strength nearly close or similar as that of virgin or normal components. The virgin and damaged specimens were taken as the reference specimens for comparison of residual mechanical properties and damage mechanisms. Damage evolution and the failure progression of the repaired glass/epoxy specimens were monitored using real‐time Acoustic Emission (AE) monitoring technique. Specimens repaired with the equal volume fraction of glass and Kevlar fibers in the external patches presented the most favorable residual compressive response by effectively releasing the stress concentration in the damaged area. POLYM. COMPOS., 39:1922–1935, 2018. © 2016 Society of Plastics Engineers

Dynamic properties of polyurea-milled glass composites Part I: Experimental characterization

Polyurea (PU) is an elastomer, which exhibits unique thermo-mechanical properties. It is synthesized from a di-functional amine, e.g. Versalink P-1000 and a diisocyanate, e.g. Isonate143L. In this study, various volume fractions milled glass (MG) was added to create polyuria-milled glass composites (PU-MG). Milled glass is a micro fiber with cylindrical shape. The distribution of the milled glass in the polyurea matrix was observed under the scanning electron microscope. The dynamic properties of pure polyurea and the PU-MG composites were measured by dynamic mechanical analysis (DMA) in the low frequency range (1–20 Hz) and by ultrasonic wave measurement in the high frequency range (0.5–1.5 MHz). Both experiments show that increasing the milled glass volume fraction drastically increases both the storage and loss moduli of the composites. DMA results show that dynamic Young’s modulus increases with increasing frequency. However, longitudinal and shear moduli from ultrasonic wave measurement appears to be insensitive to frequency within the range of 0.5–1.5 MHz. The experimental dynamic moduli master curves of PU and PU-MG composites were constructed and compared. The relaxation function or creep compliance are generally useful than dynamic moduli for modeling of material response under complex histories. It is of practical use to convert dynamic mechanical data from the frequency domain into the time domain. The discrete relaxation spectra of the composites were calculated by fitting Prony series to the master curves, using least square nonlinear regression. Retardation spectra were then calculated using the interrelation between relaxation modulus and creep compliance in Laplace domain. Finally, the time domain relaxation modulus and creep compliance for each composite were obtained from the two spectra. In order to extend our understanding of the dynamic behavior of the PU-MG composite, micromechanical models have been created and are discussed in the accompanying paper Nantasetphong (2016a).

Dynamic properties of polyurea-milled glass composites part II: Micromechanical modeling

In Part I, the results of experimental evaluation of the mechanical properties of pure polyurea (PU) and polyurea with milled glass composites (PU-MG) in low (1–20 Hz) and high (0.5–1.5 MHz) frequency ranges (Nantasetphong et al., 2016a) have been reported, focusing on the dependence of these properties on frequency, temperature, and the milled glass volume fraction. Here, we report the results of the corresponding micromechanical modeling. The models are developed, based on three different approximations: (1) dilute random, (2) non-dilute random, and (3) non-dilute periodic distributions of inclusions. Different orientation distributions of fibers, e.g., uniaxial parallel, in-plane random, and 3D random are considered and their results are compared with experimentally measured data presented in (Nantasetphong et al., 2016a). Moreover, the computational results are used to construct master curves of dynamic Young’s storage and loss moduli and compare these with those constructed from experimental data. The 3D random and in-plane random calculation results are compared with the dynamic longitudinal and shear moduli of PU-MG composites obtained from ultrasonic wave measurements. These comparisons demonstrated that, as expected, the orientation distribution of the short fibers was affected by the thickness of the composite sample, and this effect was manifested in overall elasticity tensor of the composite.

Toughness behaviour of high‐performance lightweight foamed concrete reinforced with hybrid fibres

AbstractLightweight foamed concrete (LWFC) is a concrete having structural strength with lightweight density and high flowability. High‐performance lightweight foamed concrete (HPLWFC) is used in modern concrete technology and intensively in the construction of high‐rise buildings, long‐span concrete structures, road sub‐bases and other applications. The present work deals with the fresh and hardened properties of LWFC. The fresh properties of LWFC are measured with the flow and fresh density tests. The hardened properties tests include compressive strength, flexural strength, flexural toughness, static modulus of elasticity, ultrasonic pulse velocity, water absorption and oven‐dry density. In addition, the study focuses mainly on the effect of the fibres added to LWFC mixes. Two types of fibre have been used: glass fibres and polypropylene fibres, and the combination of glass fibres (GF) and polypropylene fibres (PPF) to obtain hybrid fibres (GF+PPF).This study also focuses on the effect of hybrid fibres on the flexural toughness of HPLWFC. Trial mixes have been used to choose the optimum mix. The definition for choosing the best mix depended on three parameters: oven‐dry density, flowability and compressive strength. The volume fraction of glass and polypropylene fibres are 0.06, 0.2, 0.4 and 0.6 %, and 0.2, 0.6, 1 and 1.4 % respectively. The percentages of hybrid fibres “GF + PPF” are “0.2 + 0.6”, “0.4 + 0.6”, “0.2 + 1” and “0.4 + 1” %. The results show that the greatest increments in the compressive and flexural strengths of LWFC are 51 and 21 % respectively due to the use of 0.6 % glass fibres. On the other hand, LWFC reinforced with polypropylene fibres exhibits only a minor increase in compressive, splitting tensile and flexural strengths. The best percentage of hybrid fibres yielding the highest increment in LWFC is “0.4 % GF + 0.6 % PPF”. The results of flexural toughness tests indicate that the polypropylene fibres denote a higher efficiency in the flexural toughness than is the case with glass fibres. The flexural toughness results increase with the volume fraction of the fibres. The hybridization shows the best flexural toughness values due to the cooperative work of the glass and polypropylene fibres boost the performance of flexural toughness in pre‐crack and post‐crack zones. Therefore, the use of 0.4 %GF + 1 %PPF gives the best results in this regard.

Ultra-high tunability in polycrystalline Ba1−xSrxTiO3 thin films

Ba0.7Sr0.3TiO3 thin polycrystalline films with an ultra-high capacitance tunability approaching 5:1 at 175 kV/cm were made possible by a flux-assisted synthesis approach. In this process, a small volume fraction of a low melting temperature glass is added during low-temperature sputter deposition. Subsequent annealing activates the liquid phase, which in turn provides the mass transport needed to approach full density, to increase grain size, and to improve crystallinity, and, in so doing, achieves a stronger non-linear dielectric response. Ba0.7Sr0.3TiO3 films with 0%, 1%, 4%, and 7% BaO-3B2O3 flux exhibited grain sizes of 25 nm, 28 nm, 48 nm, and 56 nm, and dielectric tunabilities of 25%, 33%, 64%, and 80% respectively. These values represent substantial improvements when compared to conventionally processed tunable dielectric films.

Effect of ion irradiation on tensile ductility, strength and fictive temperature in metallic glass nanowires

Ion irradiation of thermoplastically molded Pt57.5Cu14.3Ni5.7P22.5 metallic glass nanowires is used to study the relationship between glass structure and tensile behavior across a wide range of structural states. Starting with the as-molded state of the glass, ion fluence and irradiated volume fraction are systematically varied to rejuvenate the glass, and the resulting plastic behavior of the metallic glass nanowires probed by in situ mechanical testing in a scanning electron microscope. Whereas the as-molded nanowires exhibit high strength, brittle-like fracture and negligible inelastic deformation, ion-irradiated nanowires show tensile ductility and quasi-homogeneous plastic deformation. Signatures of changes to the glass structure owing to ion irradiation as obtained from electron diffraction are subtle, despite relatively large yield strength reductions of hundreds of megapascals relative to the as-molded condition. To reconcile changes in mechanical behavior with glass properties, we adapt previous models equating the released strain energy during shear banding to a transit through the glass transition temperature by incorporating the excess enthalpy associated with distinct structural states. Our model suggests that ion irradiation increases the fictive temperature of our glass by tens of degrees – the equivalent of many orders of magnitude change in cooling rate. We further show our analytical description of yield strength to quantitatively describe literature results showing a correlation between severe plastic deformation and hardness in a single glass system. Our results highlight not only the capacity for room temperature ductile plastic flow in nanoscaled metallic glasses, but also processing strategies capable of glass rejuvenation outside of the realm of traditional thermal treatments.