Glass Layer Research Articles

Investigation of the Flexural Behavior and Damage Mechanisms of Flax/Cork Sandwich Panels Manufactured by Liquid Thermoplastic Resin

This study investigates the flexural behavior of three sandwich panels composed of an agglomerated cork core and skins made up of cross-ply [0,90]2 flax or glass layers with areal densities of 100 and 300 g/m2. They are designated by SF100, SF300, and SG300, where S, F, and G stand for sandwich material, flax fiber, and glass fiber, respectively. The three sandwich materials were fabricated in a single step using vacuum infusion with the liquid thermoplastic resin Elium®. Specimens of these sandwich materials were subjected to three-point bending tests at five span lengths (80, 100, 150, 200, and 250 mm). Each specimen was equipped with two piezoelectric sensors to record acoustic activity during the bending, facilitating the identification of the main damage mechanisms leading to flexural failure. The acoustic signals were analyzed to first track the initiation and propagation of damage and, second, to correlate these signals with the mechanical behavior of the sandwich materials. The obtained results indicate that SF300 exhibits 60% and 49% higher flexural and shear stiffness, respectively, than SG300. Moreover, a comparison of the specific mechanical properties reveals that SF300 offers the best compromise in terms of the flexural properties. Moreover, the acoustic emission (AE) analysis allowed the identification of the main damage mechanisms, including matrix cracking, fiber failure, fiber/matrix, and core/skin debonding, as well as their chronology during the flexural tests. Three-dimensional micro-tomography reconstructions and scanning electron microscope (SEM) observations were performed to confirm the identified damage mechanisms. Finally, a correlation between these observations and the AE signals is proposed to classify the damage mechanisms according to their corresponding amplitude ranges.

Design Optimization for Hydrostatic Pressure in Hybrid Composite Cylinders

AbstractThis study explores an optimization system to achieve the highest collapse pressure on glass-carbon hybrid composite cylinders under hydrostatic loading conditions. This work evaluates and validates previously established composite buckling solutions for cylindrical composite structures under hydrostatic pressure with experimental results of hybrid composite shells. It utilizes the validated analytical solution to optimize the buckling pressure by varying layup configuration, optimum layup angle, material content, and thickness of each lamina. The optimization is performed on asymmetric and symmetric layup cases to evaluate the influence of the hybrid layup construction on the buckling performance of the structure. Results show that the thicker glass fiber plies are preferred for inner layers and the stiffer carbon fiber plies for the outermost layers to achieve maximum buckling collapse pressure for all the optimization cases, as this configuration provides superior flexural rigidity. For hybrid composite structures with asymmetric configurations, the collapse pressure can be higher when most layers are made of glass fiber if the glass layers are at least twice as thick as the carbon layers. Similarly, axial-load-resistant layers (0°) should be located around the geometric center of the laminate with the hoop-load-resistant layers (90°) on or near the outermost layers and shear-resistant layers (45°) between these layers for both symmetric and asymmetric hybrid structures. Moreover, long tubes with small diameters (L/D > 10) favor hoop bending stiffnesses (90°) for all layers in the laminate due to less influence of boundary conditions at endcap locations.

Influence of layering variation with addition of bio-fillers on mechanical and thermal performances of hybrid polyester composites

The extensive application of composites reinforced with synthetic or natural fibers and bio-fillers represents a recent advanced trend in research. This research seeks to assess the optimal ratio of wood dust (WD) and fish scale powder (FSP) for forming a hybrid filler mix to reinforce Palmyra Palm leaf stalk (P)/Glass (G) polyester laminate, aiming to improve its mechanical and thermal properties. The ideal ratio is identified by evaluating the mechanical properties of various weight fraction combinations of WD and FSP filler in polyester. The test results showed that the optimal filler hybridization ratio is 5 wt.% WD and 10 wt.% FSP. Hybrid laminates are then produced by combining equal layers of glass and palm leaf stalk fiber in different stacking configurations, incorporating an optimal mixture of hybrid fillers. The experimental findings revealed that, the inclusion of an optimal blend of WD and FSP filler results in improvements in mechanical properties, with a 51.93% increase in tensile strength, a 36.27% boost in flexural strength, a 20.48% rise in impact resistance, and a 10.08% enhancement in micro-hardness. Additionally, the findings revealed that the laminate with GPPG stacking order shows the highest mechanical properties compared to other stacking sequences. To further examine the thermal degradation and various failure mechanisms, Thermo-gravimetric analysis (TGA) and fractography study using a Scanning Electron Microscope (SEM) are conducted.

Modification of glass screen printed electrodes with graphene quantum dots for enhanced power output in miniaturized microbial fuel cells

This paper demonstrates screen-printing technique, Glass Screen printed (GSP) on glass layer with Graphene Quantum Dots (GQDs) via drop casting approach to manufacture electrodes for Miniaturized Microbial Fuel Cells (MMFCs). MMFCs are viable options to sustainably operate low-power devices such as sensors, implantable medical devices, etc. However, the technology is still not fully mature for practical applications due to limitations of output power. Materials and design improvements are required for decreasing internal resistance for better electron transfer and improving overall performance. In this work the electrodes manufactured by GSP technique, and anode modified by GQD was tested in MMFC using RO wastewater. It was found that the GQDs increased the surface area to improve electron transfer kinetics at the anode. As a result, GQDs-based GSPEs showed 7.4 times higher power output 332 nW/cm2 compared to its unaltered electrode which displayed a power output of 44.8 nW/cm2. Electrodes made by GSP technique are more durable and less susceptible to biofouling and corrosion compared to conventional methods. The modified anodes further showed sustained output for long term operation.

Finite prism approach for stability analysis of laminated glass fins

The use of laminated glass (LG) as a structural material for load-bearing components within buildings has been growing over the last decades. LG can be obtained by bonding two or more pieces of glass by means of polymeric interlayers (e.g., poly vinyl butyral – PVB). This building process gives LG elements a huge advantage over the same ones made of fully monolithic glass with respect to safety, since after breakage the fragments usually remain attached to the interlayer, reducing the risk of injuries. As LG members usually present a high slenderness, they are susceptible to flexural buckling under compression, requiring specific calculation methods and verification procedures in order to guarantee appropriate and safe structural performance. Compared to literature, this work presents a novel approach that is focused on the prediction of the elastic critical buckling load of LG columns without any lateral restraints at the tensioned edges. The buckling loads of LG columns have been determined using Finite Element Method, generally using shell elements, or analytical models. Usually, such approaches make use of the concept of effective thickness, in which the thickness of a monolithic element with equivalent bending properties in terms of stress and deflection is employed. However, the effective thickness approach is either difficult to apply or inaccurate. Therefore, this work presents an efficient and accurate approach to evaluate elastic critical buckling loads of LG columns applying Finite Prism Method (FPM). The accuracy of the proposed approach is assessed comparing the results obtained using solid finite element and analytical models for fully monolithic glass columns, as well as LG columns composed by multiple glass layers.

Slag rim structure and phase formation mechanism in molds during the continuous casting of high-Mn high-Al steel

The slag–steel reaction between low basicity mold flux and high-Mn and high-Al steel results in changes to the composition and properties of the mold flux, forming a slag rim at the meniscus of the mold during continuous casting. In this study, the slag rim was divided into five layers comprising the glass, columnar crystals, fine crystals, coarse crystals, and sinter layers from mold to molten steel based on their morphological features. Compared to the original slag, the Al2O3 content in the slag rim significantly increased and the SiO2 content decreased, thereby increasing the Al2O3/SiO2 mass ratio from 0.05 to 5.52. Phases with high melting points, such as Na2O·CaO·2Al2O3 and LiAlO2, were identified in the slag rim. According to crystallization process calculations using FactSage, these phases were the primary causes of slag rim formation. Thus, new slags with a low O/F mass ratio were subsequently designed to mitigate the generation and growth of Na2O·CaO·2Al2O3. These new compositions reduced the melting point and viscosity, thereby ensuring sufficient fluidity in slags with a high Al2O3/SiO2 mass ratio.

Kinetics of thermal and photoinduced diffusion of Ag into thin layers of chalcogenide glasses

This study examines the kinetics of thermal diffusion of silver in Ag-GeSe2 and Ag- As10Ge30S60 thin film structures during prolonged storage in the dark at room temperature, as well as the effects of plasmon-enhanced photostimulated diffusion of silver into As10Ge30S60 films. Ag diffraction gratings with a period of 519 nm were used to excite surface plasmon-polaritons (SPP) at the silver-chalcogenide glass interface. It was found that the thermal diffusion coefficient of silver into GeSe2 is significantly higher than into As10Ge30S60. For Ag– As10Ge30S60, photostimulated silver diffusion coefficients were measured with and without SPP excitation. SPP excitation triples the photostimulated Ag flux into As10Ge30S60. Although photosensitivity decreases over time, the plasmon-stimulated increase in Ag flux remains stable. Additionally, As10Ge30S60 thermally doped with silver shows much higher optical absorption at the probing wavelength compared to the photodoped layer with the same silver concentration. Possible mechanisms of these layers formation are discussed.

A novel prediction model for the solar radiation absorptivity and reflectivity of cooling photovoltaic panels with water layer

Water cooling of photovoltaic(PV) panels is a cost-effective technique for increasing electrical efficiency. However, there is a lack of a calculation method to accurately predict the solar radiation absorptivity and reflectivity of the double-layer transparent structure consisting of water and glass layers. In this study, based on the analysis of direct radiation light rays in the structure, an equivalent energy model was presented. Thereafter, according to the isotropic radiation within a hemispherical space, the absorptivity and reflectivity of the diffuse radiation were calculated. The effectiveness of the model is verified by the measured transmitted radiation through the horizontal and inclined glass panels in Xiamen city (117°57'E, 24°25'N) of China. The accuracy of simulation is better than that of the calculation methods in the literature. The model is capable of accurately predicting the absorptivity and reflectivity of solar radiation for a diverse range of application contexts and panel types. The simulated results reveal that when the incidence angle exceeds 60°, the absorptivity of PV cell layer decreases markedly. The direct radiation absorptivity of the glass and water layers increases gradually within an incidence angle of 60°, and then decreases as the angle increases. The reflectivity increases slowly when the incidence angle varies from 0° to 50°. The water layer minimally affects the glass layer's solar absorptivity and slightly decreases the reflectivity. But a 1 mm thick water layer can reduce the absorptivity of the PV cell layer by about 0.05, which corresponds to a 7.4 % decrease. The reduction is more pronounced with an increase in the water layer thickness. The prediction model can provide solar radiation absorptivity and reflectivity parameters of PV panels for water cooling simulations.

Application of Triple Glazing Thickness Optimization Based on Artificial Fish Swarm Algorithm

In response to the growing demand for energy-efficient building designs in cold northern regions, this study explores the optimization of triple glazing thickness to maximize the transmission of solar energy within the wavelength range of 300-2000 nm. The optimization employs the Artificial Fish Swarm Algorithm (AFSA), which is used to iteratively determine the optimal combination of glass thicknesses. A transmittance model of solar radiation through triple glazing is established, where the thicknesses of the three glass layers are treated as variables. The study shows that the optimized thickness combination significantly enhances the indoor heating effect by maximizing solar energy incidence, offering theoretical support and practical guidance for energy-saving building designs in cold climates. Parameter settings of the AFSA, including perception range, step size, and crowding factor, are analyzed to understand their influence on optimization performance. The results suggest that AFSA efficiently addresses complex optimization problems, demonstrating its potential in optimizing material properties for energy-efficient applications. Future directions include multi-objective optimization considering additional factors such as thermal insulation and cost, algorithmic improvements to enhance search accuracy, and experimental validation of the results in real-world conditions. This research provides a scientific foundation for integrating advanced optimization algorithms into the sustainable design of building materials.

Enhancing Greenhouse Efficiency: A Quantum Genetic Algorithm Approach to Optimal Glass Thickness

Greenhouses are pivotal in extending the growing season for various crops by creating conducive environments that enhance plant growth. A critical factor in maximizing the efficiency of greenhouses is the optimization of light transmittance through multi-layer glass structures. This not only supports plant health but also conserves energy by maintaining a warmer internal climate. The application of quantum genetic algorithms (QGAs) to this context represents a significant advancement, as these algorithms excel in handling multi-objective optimization challenges. By targeting the precise calibration of glass thickness, QGAs can substantially influence the amount of solar energy harnessed within the greenhouse, especially when the sun is directly overhead at noon. This paper presents an in-depth study on the use of quantum genetic algorithms to optimize the thickness of three distinct layers of glass in greenhouse settings. Our findings reveal that QGAs are capable of generating various combinations of glass thickness that not only maximize the total energy transmitted but also ensure stability in the energy output across different scenarios. The robustness of QGAs in consistently deriving optimal solutions underscores their potential as a superior technique in architectural design for agricultural applications. Comparative analysis with classical genetic algorithms and random number optimization techniques further demonstrates the superiority of quantum genetic algorithms.

Enhancing oxygen‐blocking properties of HfB2‐MoSi2‐SiC coating by CeO2 modification

AbstractTo alleviate the destructive alteration of the glass layer surface caused by gas evolution during the oxygen‐blocking process of the HfB2‐MoSi2‐SiC coating, CeO2 was incorporated to modify HfB2‐MoSi2‐SiC coating, and the anti‐oxidation mechanism at 1700°C in air was investigated. Compared with the unmodified HfB2‐MoSi2‐SiC coating, the addition of the refractory CeO2 to the Hf‐B‐Si‐O system leads to the formation of a stable Hf‐Ce‐B‐Si‐O complex phase glass, which substantially enhances the viscosity, stability, and self‐healing sealing properties of the glass layer. The introduction of 0.75 vol.% CeO2 significantly lowers the oxidative activity of the HfB2‐MoSi2‐SiC coating, boosting its average protective efficiency to 99.96% and reducing the maximal oxygen permeability by 43.48%, thus exhibiting superior oxygen‐blocking performance. However, excessive addition of CeO2 leads to an overabundance of oxygen release through its distinctive oxygen vacancy mechanism, which accelerates the formation of Hf‐oxides, resulting in excessive viscosity on the coating surface and leaving oxidation defects unrepaired.

Macro/micro failure mechanism of transparent armour subjected to multiple impacts of 7.62mm bullets

Transparent armor is widely used in military and civilian impact protection fields due to its excellent light transmittance and ballistic performance. This work focused on the macro/micro failure mechanisms of transparent armor for vehicles subjected to multiple impacts. Results showed that the penetration depth after the first impact by a 7.62 mm bullet is about 14 mm, regardless of the impact position. Based on the cavity expansion theory, the penetration depth under multiple projectile impacts was predicted, relating it to the distance between the impact points, the distance from the projectile hole to the edge of the target plate, and the damage radius caused by the first impact. In the thickness direction, observation of the glass layer damage modes revealed that the interlayer adhesive could hinder the propagation of vertical cracks between different glass layers, with delamination primarily caused by insufficient shear strength. In the in-plane direction, the size of the fractured glass gradually increases outward from the impact point because circumferential cracks can prevent the propagation of radial cracks. Finally, the micro failure analysis of glass fragments showed that the radial cracks are dominated by numerous irregular microcracks and river-like textures, while the circumferential cracks consist of the mirror region, mist region, hackle region, and river-like texture region.

Effect of Triple Glass Layers on the Thermal Performance of Windows

This study introduces the application of software simulations to evaluate the performance of triple-pane glass windows to meet the requirements for energy-efficient thermal insulation. Using Therm 7.8.55 and Window 7.8.55 software, structural and physical heat transfer models for various single-frame plastic windows were developed. Numerical simulation methods were employed to calculate and analyse the impact of the number of glass layers on the windows' thermal performance, including the heat transfer coefficient and solar heat gain coefficient, to elucidate the energy-saving mechanisms. These simulations examined the physical properties of single-frame triple-glazed plastic windows, such as wind pressure resistance, airtightness, watertightness, and potential condensation on the inner surface. The results indicate that, under identical conditions, the heat transfer coefficient of single-frame triple-glazed plastic windows is reduced by 7.08%, and the solar heat gain coefficient is decreased by 4.18% compared to single-frame double-glazed plastic windows. Additionally, these windows' physical and economic performance meets the necessary standards. Furthermore, incorporating new materials such as Low-E glass can further enhance the thermal performance of the windows, significantly contributing to the reduction of overall building energy consumption.

Quenching of silver clusters luminescence by Eu(III) and Sm(III) ions in ion-exchanged layers of silica-based glass

Series of silica-based glasses doped with La2O3, Eu2O3, and Sm2O3 was synthesized to host luminescent silver clusters formed via Na+-Ag+ ion exchange and heat treatment. Photoluminescence spectra of the glasses with Eu3+ or Sm3+ ions consist of broad white emission from silver clusters and characteristic bands of rare-earth ions. Energy transfer between silver clusters and Eu3+ or Sm3+ ions was studied by controlling luminescence quantum yield and lifetime of silver clusters. Rare-earth doping of the studied glass decreases the amount of forming silver clusters, therefore, the quenching efficiency of Eu3+ and Sm3+ ions was calculated in comparison to the glasses doped by La3+. It was shown that quantum yield of cluster luminescence decreases faster than the fluorescence and phosphorescence lifetime in the presence of Eu3+ or Sm3+ ions. Difference in quenching efficiency of luminescence quantum yield and emission lifetime of silver clusters was explained by the coexisting of two different mechanisms of quenching.

Amended Calculation of Solar Heat Gain Coefficient Based on the Escape of Incident Solar Radiation

The solar heat gain is an important component of building cooling load, and its magnitude affects building energy consumption directly. In buildings with glass curtain walls, the window to wall rate is close to 1, so the amount of solar heat gain is huge, which directly determines the energy consumption level of a building’s air conditioning system. In fact, incident solar radiation can escape to the exterior through the transparent envelope, which cannot be ignored in buildings with glass curtain walls. This will cause changes in solar heat gain, so the solar heat gain coefficient (SHGC) needs to be corrected. In this paper, the heat transfer process of solar radiation in window shading systems is analyzed, and an amended calculation model for the SHGC is established. Multiple forms of windows and shading systems are selected and their SHGC-amended factor for rooms with different orientations under different standard calculation conditions in various countries is calculated. As the number of glass layers increases, the transmittance of the window gradually decreases, the reflectance and absorbance gradually increase, and the SHGC value decreases. The SHGC-amended factor decreases with an increasing escape rate, and the two can be approximated as a linear correlation. The weakening effect of shading on the solar heat gain of the buildings is overestimated. The SHGC-amended factor proposed in this paper can calculate building solar heat gain more accurately.

Low-velocity impact damage characteristics of flax/glass epoxy hybrid laminates on the influence of different temperatures: Experimental and numerical analysis

This study investigated the effects of different temperatures on the low-velocity impact damage behaviour of flax fibre-reinforced epoxy composites and their glass/flax hybrids. Composites reinforced with flax, glass, and hybrid flax/glass onto epoxy matrix Subjected to low-velocity drop weight impact tests at 5 J of incident impact energy at sub-zero temperatures (−10 °C and −20 °C) and at room temperature (RT) are presented. Under the different temperatures, the experimental findings showed a beneficial hybrid effect where the temperature played a significant role. At RT, the Lam-GFGFGFG exhibit improved impact resistance, with enhanced energy absorption capabilities compared to glass-only laminates (Lam-G). Besides, Lam-GFFFFG laminates exhibit a significant difference in the force–displacement curves at − 20 °C, with a maximum load of 801.95 N in contrast to RT and − 10 °C resulting in a gradual increase in force with increasing displacement. This indicates that Lam-GFFFFG laminates can resist the impact and maintain structural integrity at sub-zero temperatures. The alternation of glass and flax layers in the hybrid structure contributes to the synergistic effects, resulting in improved damage resistance and tolerance. Also, the highest impact tolerance in a laminate is achieved through the hybridisation of flax fibre-reinforced composites with glass-reinforced layers on the outer surfaces (Lam-GFFFFG) at − 10 °C. Subsequently, experimental results were compared with finite element analysis (FEA) results, derived from a model built using a VUMAT subroutine integrated with ABAQUS/Explicit for a more accurate representation of the damage characterisation of the composite laminates under low-velocity impact.

Optimization of Triple-Layer Glass Thickness for Maximizing Sunlight Incidence in Northern Winter Using Ant Colony Algorithm

Abstract. This study investigates the optimization of multilayer glass thickness to maximize solar heat gain in buildings located in cold northern climates, utilizing the Ant Colony Optimization (ACO) algorithm. The research focuses on enhancing thermal comfort and reducing energy consumption by optimizing the thickness of three glass layers, thereby improving solar energy transmission into indoor spaces. ACO, a metaheuristic inspired by the foraging behavior of ants, is employed due to its robustness in handling complex optimization problems. The study incorporates wavelength-specific considerations into the ACO framework to achieve a sophisticated optimization approach, resulting in improved solar energy transmission. The experimental results demonstrate that the optimized glass configuration significantly increases sunlight transmittance, especially within the target wavelength range, contributing to more energy-efficient and comfortable architectural designs. This research highlights the potential of ACO in optimizing building materials and suggests further refinement of the algorithm for enhanced performance in real-world applications.

Enhancing Multilayer Glass Transmittance through Particle Swarm Optimization: An Experimental Approach

Abstract. This study focuses on enhancing the solar transmittance of multilayer glass in buildings located in cold northern regions to improve natural lighting efficiency and maintain indoor warmth in harsh climates. The Particle Swarm Optimization (PSO) algorithm is utilized to optimize the glass layer thickness, and an optical model is constructed to calculate the light transmittance of the multilayer glass. Through simulations and experimental analysis, the impact of different glass thickness combinations on overall transmittance is investigated. The study examines the optical properties of gradient glass and calculates changes in light transmittance under varying thickness combinations using MATLAB software. The PSO algorithm is applied for global optimization to identify the glass thickness combination that maximizes light transmittance within the specific visible light range (400nm-800nm). The experimental results, including spectral energy distribution before and after sunlight transmission, validate the accuracy of the theoretical model. The findings demonstrate that the optimized glass thickness combination significantly improves solar transmittance, especially within the visible light band, contributing to more energy-efficient and comfortable building environments in cold regions. Additionally, the potential of the PSO algorithm in global search and local convergence is analyzed, suggesting future research directions to further enhance optimization through dynamic adjustments or combining with other algorithms.

Quantum Genetic Algorithm-Driven Optimization of Triple-Glazed Window Thickness for Enhanced Light Reduction

Abstract. Glass, a common construction material, generally lacks significant thermal properties. As technology rapidly advances, the demand for glass materials with superior heat preservation and thermal insulation capabilities increases, driven by the need to reduce building energy consumption. Multi-objective optimization problems, particularly in complex multilayered systems, require advanced numerical optimization algorithms. The quantum-inspired genetic algorithm (QIGA) offers advantages such as fast solving speed and high precision, utilizing quantum coding, variation, rotation gates, and crossing techniques. This study focuses on designing the optimal thickness of triple-layer glass to minimize sunlight penetration through windows, using QIGA to achieve this goal. The results demonstrate that triple glazing effectively reduces solar radiation entering a room, though different layer combinations lead to significant variations in total energy reduction. The study also emphasizes the importance of concurrent research in glass layer splicing technology, coating film techniques, and new glass materials to enhance overall performance. These findings contribute to the development of energy-efficient building materials that meet modern standards for thermal insulation and light control.

Quantum Genetic Algorithm-Driven Optimization of Triple-Glazed Window Thickness for Enhanced Light Reduction

Abstract. Glass, a common construction material, generally lacks significant thermal properties. As technology rapidly advances, the demand for glass materials with superior heat preservation and thermal insulation capabilities increases, driven by the need to reduce building energy consumption. Multi-objective optimization problems, particularly in complex multilayered systems, require advanced numerical optimization algorithms. The quantum-inspired genetic algorithm (QIGA) offers advantages such as fast solving speed and high precision, utilizing quantum coding, variation, rotation gates, and crossing techniques. This study focuses on designing the optimal thickness of triple-layer glass to minimize sunlight penetration through windows, using QIGA to achieve this goal. The results demonstrate that triple glazing effectively reduces solar radiation entering a room, though different layer combinations lead to significant variations in total energy reduction. The study also emphasizes the importance of concurrent research in glass layer splicing technology, coating film techniques, and new glass materials to enhance overall performance. These findings contribute to the development of energy-efficient building materials that meet modern standards for thermal insulation and light control.