Lining Materials Research Articles

Structural improvement of 3D woven honeycomb composite liner for enhanced energy absorption and impact performance in aircrew helmet

This study aims to enhance the performance of aircrew helmet liners made of 3D woven honeycomb composites through structural improvements. To achieve this, an optimization of the honeycomb design was carried out using a statistical tool by varying its geometrical parameters. A Box Behnken design was employed, using three independent factors: cell height, cell size, and cell wall thickness to assess its impact and their interactions on responses. The performance was evaluated using a multiobjective response to maximize impact energy absorption, achieve the target cushion factor, and balance relative density for lightweight design. Since the liner materials were subjected to flatwise compression and dynamic impact tests to assess the performance. Their behavior. The results revealed that the honeycomb core with a cell height of 15 mm, a cell size of 10 mm, and a cell wall thickness of 0.6 mm exhibited good behavior. The response surface analysis and contour plots were used to analyze the interactions and combined effects of variables on each response. It was observed that lesser cell size shows significant improvement in impact energy with higher wall thickness. However, the cushion factor implies inadequate energy mitigation. The analysis comparing desirability and confirmatory experiments highlighted the potential for the aircrew helmet liner to achieve its maximum performance. This study provides valuable insights into the structural design of 3D woven honeycomb composite liners for aircrew helmets and its findings signify the potential for applications in the aerospace and defense industries.

Estimating seepage losses from lined irrigation canals using nonlinear regression and artificial neural network models

The Slide2 model was used to estimate seepage losses from canals after validation considering different canal geometries, lining thicknesses, and lining materials. SPSS was used to develop three models: NLR, MLP-ANN, and RBF-ANN. MATLAB software was used to write down the script code for the ANNs. Results showed that seepage losses were highly increased when the liner had high hydraulic conductivity, while with the increase of lining thickness, a noticeable reduction in seepage losses was obtained. The canal's side slope had a minimal effect on the seepage losses. Moreover, the MLP-ANN and RBF-ANN models performed better than the NLR model with determination coefficient (R2) of 0.996 and 0.965; Root-Mean-Square-Error (RMSE) of 1.172 and 0.699; Mean-Absolute-Error (MAE) of 0.139 and 0.528; index of agreement (d) = 0.999 and 0.991, respectively. The NLR model had lower values of R2 = 0.906, RMSE = 1.198, MAE = 0.942, and d = 0.971. Thus, ANNs are recommended as a robust, easy, simple, and rapid tool for estimating seepage losses from lined trapezoidal irrigation canals.

Utilization of Rubber Wood Ash–Clay Mixes as Bottom Liner Material in Solid Waste Landfills: Engineering Properties and Microstructural Characteristics

Utilization of Rubber Wood Ash–Clay Mixes as Bottom Liner Material in Solid Waste Landfills: Engineering Properties and Microstructural Characteristics

Molecular Simulation Study on the Hydrogen Permeation Behavior and Mechanism of Common Polymers.

This research aimed to provide an understanding of the selection and safe application of pipeline liner materials for hydrogen transport by examining the permeation properties and mechanisms of hydrogen within polymers commonly used for this purpose, such as high-density polyethylene (HDPE) and ethylene-vinyl alcohol copolymer (EVOH), through molecular simulation. The study was carried out within defined operational parameters of temperature (ranging from room temperature to 80 °C) and pressure (from 2.5 to 10 MPa) that are pertinent to hydrogen pipeline infrastructures. The results reveal that with an increase in temperature from 30 °C to 80 °C, the solubility, diffusion, and permeability coefficients of hydrogen in HDPE increase by 18.7%, 92.9%, and 129.0%, respectively. Similarly, in EVOH, these coefficients experience increments of 15.9%, 81.6%, and 112.7%. Conversely, pressure variations have a negligible effect on permeability in both polymers. HDPE exhibits significantly higher hydrogen permeability compared to EVOH. The unique chain segment configuration of EVOH leads to the formation of robust hydrogen bonds among the hydroxyl groups, thereby impeding the permeation of hydrogen. The process by which hydrogen is adsorbed in polymers involves aggregation at low potential energy levels. During diffusion, the hydrogen molecule primarily vibrates within a limited range, with intermittent occurrences of significant hole-to-hole transitions over larger distances. Hydrogen exhibits a stronger interaction with HDPE compared to EVOH, leading to a higher number of adsorption sites and increased hydrogen adsorption capacity in HDPE. Hydrogen molecules move more actively in HDPE than in EVOH, exhibiting greater hole amplitude and more holes in transition during the diffusion process.

Design and comparative analysis of alternative mooring systems for offshore floating photovoltaics arrays in ultra-shallow water with significant tidal range

Large-scale floating photovoltaics (FPV) are garnering increased attention as a sustainable solution for renewable energy production and efficient utilization of ocean spaces. These FPV arrays are predominantly deployed in shallow water environments, which present significant challenges in mooring system design due to substantial tidal fluctuations. In such settings, mooring systems may become slack and lose functionality at low tide or risk damage from excessive stiffness at high tide. The primary aim of this study is to develop a mooring system tailored to FPV arrays, capable of withstanding extensive tidal variations without causing damage to the floating modules due to high mooring line tension. Employing HydroD, a hydrodynamic analysis tool based on potential flow theory, alongside OrcaFlex, a time-domain coupled analysis tool predicated on the lumped mass method, we conducted a comparative assessment of six distinct mooring configurations. These configurations, varying in mooring line materials and components, were evaluated from static, dynamic, and fatigue analysis standpoints across a range of tidal levels. The results indicate that taut mooring systems integrated with buoys or clumps consistently exhibit superior performance in all test scenarios. Accordingly, these systems are highly recommended for securing FPV arrays in shallow water environments characterized by severe tidal variations, offering optimal stability and resilience.

Radiopacity evaluations of the novel calcium-silicate and glass-Ionomer-based materials

Aims: Radiopacity is a crucial property for a liner or base material, and these materials should provide an optimal contrast for detecting secondary caries in radiographic examinations. The purpose of this study was to assess the radiopacity characteristics of four calcium-silicate-based and two glass-ionomer-based materials used as a liner or base in direct or indirect vital pulp therapy.
 Methods: A total of 60 cylindrical-shaped and 1 mm thick specimens were prepared from a calcium-silicate (Biodentine, Septodont), a calcium-silicate (MTA, Angelus), a light-cured resin-modified calcium silicate (TheraCal LC, Bisco), a dual-cured resin-modified calcium silicate (TheraCal PT, Bisco), a glass hybrid glass-ionomer (Equia Forte HT, GC), and a resin-modified glass ionomer (Glass Liner, Wp Dental) material (n=10). Digital radiographic images of the specimens, a molar tooth section with 1 mm thickness, and an aluminum step wedge were obtained by a digital radiography system (Heliodent Plus, 
 Dentsply Sirona) with 60 kV voltage, 7 mA current, and 0.25 seconds exposure time. The mean gray values (MGV) of digital images were determined using the ImageJ software program (National Institute of Health, Bethesda, MD, USA). Kruskal-Wallis and Mann-Whitney tests (pBiodentine>Equia Forte HT>Theracal PT>Theracal LC>Glass Liner, respectively. All the tested liner or base materials exhibited significantly greater radiopacity values when compared to those of dentin (p

Vulnerability of Thermal Energy Storage Lining Material to Erosion Induced by Particulate Flow in Concentrated Solar Power Tower Systems.

Researchers from all around the world have been paying close attention to particle-based power tower technologies. On the King Saud University campus in the Kingdom of Saudi Arabia, the first integrated gas turbine-solar particle heating hybrid system has been realized. In this study, two different types of experiments were carried out to examine how susceptible prospective liner materials for thermal energy storage tanks were to erosion. An accelerated direct-impact test with high particulate temperature was the first experiment. A low-velocity mass-flow test was the second experiment, and it closely mimicked the flow circumstances in a real thermal energy storage tank. The tests were conducted on bare insulating fire bricks (IFBs) and IFBs coated with Tuffcrete 47, Matrigun 25 ACX, and Tuffcrete 60 M. The latter three lining materials were high-temperature-resilient materials made by Allied Mineral Products Inc. (AMP) (Columbus, OH, USA). The results showed that although IFBs coated with AMP materials worked well in this test, the accelerated direct-impact test significantly reduced the bulk of the bare IFB. As a result, lining substances must be added to the surface of IFBs to increase their strength and protection because they cannot be used in situations where particles directly impact their surface. On the other hand, the findings of the 60 h cold-particle mass-flow test revealed that the IFBs were not significantly eroded. Additionally, it was discovered that the degree of erosion on the samples of bare IFB was unaffected by the height of the particle bed.

Column percolation leaching test for rare-earth processed residue: Standard laboratory column elution experiments towards development permanent disposal facility (PDF)

The rare-earth industry in Malaysia primarily produces two main by-products in vast quantities: Water Leach Purification (WLP) and Neutralisation Underflow (NUF) residue. The average total concentration of rare earth elements (TREE) in WLP and NUF was discovered to be 54.2 g/kg and 29.5 g/kg, respectively. The heavy metal (HM) concentration for both was below the Malaysian soil intervention threshold except for arsenic and lead. The average thorium (Th) concentration of WLP exceeded the 1 Bq/g regulatory threshold. Such Th concentration prompted the need for WLP residues to be stored in a permanent disposal facility (PDF). The proposed PDF intends to take advantage of the gypsum properties of the NUF by deploying it as a liner material. It was discovered that the repurposing of NUF increases the pH of a single composition of WLP from 3.6 to a less acidic condition. The three different layer mixes of composition ratio NUF to WLP (PC3, PC4, PC5) of the study lead the pH of the effluent to range between 5 and 6, as compared to the pH range of 9.8–10.2 for NUF composition solely. The optimum composition ratio of NUF to WLP proposed by the study for the PDF is 1:19 (PC5), as the leaching of Th, HM, and REE in this condition is shown to be insignificant.

Research on the destroy characteristics of PTFE/Cu composite liner to explosive reactive armor

The jet generated through PTFE based inert material liner has the characteristics of low energy, low density, and large aspect ratio, which can effectively achieve the “penetration without explosion” of explosive reactive armor. PTFE/Cu composite material liner with various densities is prepared, to research the roles of preparation procedure and density in the destroy effect of jet on reactive armor. Through numerical simulation research, it was found that there was no reaction at all in the explosive layer penetrated by the jet generated by the sinter liner molded, while the explosive layer penetrated by the jet generated through the hot-pressing sintering and extrusion molding liner experienced local reactions on the jet impact channel, and the overall explosive layer did not undergo any reaction. Through experimental verification, it has been proven that all three types of jets have achieved “penetration without explosion” on explosive reactive armor.

Comparison of performance and tribological properties of electromechanical brake with magnetorheological fluid and magnetic powder

Brakes, which are the safety component of any automobile used to control the motion of the vehicle as per the driver's choice. In conventional brakes, friction lining materials are used, which affect the health of human beings and pollute the environment. Hence, there is a need to look for new types of brake systems. In the present work, a new type of electromechanical (EM) drum brake is designed that does not use friction lining materials for brake application. It can use magnetorheological (MR) fluid as well as magnetic powder (MP) for brake application. The presented brake has been designed to operate in hybrid mode that is, shear plus compression mode. When MR fluid is used, these brakes face the problem of the leakage of MR fluid which motivates to use of MP. In addition to the design of the new brake, the performance of the new brake has been tested with MR fluid and MP separately on a full-scale brake inertia dynamometer. The performance test results have been compared for both MR fluid and MP and compared with conventional friction brakes. 14.56% and 11.38% more braking torque have been observed for MP compared to that of MR fluid in shear and hybrid mode respectively. In addition to the performance study, the effect of MR fluid and MP on brake shoe surface properties has been studied.

Enhanced interfacial and tribological properties of fabric liner by constructing a MXene/HNTs/PAMAM hierarchical coating

AbstractA special “hard‐soft” MXene/Halloysite nanotube (HNTs)/ poly(amidoamine) (PAMAM) structure was constructed to improve the interfacial and tribological performances of fabric liner (FL) materials. Thereinto, the MXene/HNTs coating were successfully grafted onto fabric surface by electrostatic self‐assembly strategy, and a novel PAMAM dendrimer polymer terminated by amino groups was prepared via condensation reaction. The mechanical and tribological performances of MXene/HNTs/PAMAM@FL as well as wear mechanism were systematically evaluated. Specifically, the incorporation of MXene/HNTs/PAMAM coating enhanced the bonding strength by 62.4%, and declined the wear rate by 27.7% in comparison with pure FL. The splendid performance was ascribed to the synergistic effect of “soft” toughening PAMAM polymer and “hard” lubricating MXene/HNTs hybrids. The introduction of MXene/HNTs hybrids could enhance mechanical interlocking and bearing capacity. Then PAMAM polymer ameliorated interfacial adhesion and compatibility with resin via forming chemical bonds, which further reducing stress concentration through increased crack deflections due to the steric hindrance.Highlights MXene/HNTs/PAMAM coating was prepared via electrostatic self‐assembly and condensation reaction. Interfacial adhesion of fabric liner achieved effective promotion. High‐quality tribofilm was constructed by the synergistic enhancement effect between MXene/HNTs particles and PAMAM polymer. The tribo‐chemical reactions participate in improving the lubricity and durability of tribofilm.

Effect of ladle-lining materials on inclusion evolution in Al-killed steel during LF refining

Abstract The effect of lining materials (Al2O3 and Al2O3–MgO·Al2O3) of ladle on evolution of non-metallic inclusions in aluminum-killed (Al-killed) steel during ladle furnace refining without Ca treatment was investigated through industrial experiments. The results showed that non-metallic inclusions experienced the changes from Al2O3 → MgO–Al2O3 → CaO–Al2O3. During the refining process using either of the two ladle lining materials, for all non-metallic inclusions, the vast majority are distributed in the high Al2O3 area of the CaO–Al2O3–MgO phase diagram, with very little or none in the low melting point zone. Non-metallic inclusions are mainly smaller than 3 μm, while those larger than 3 μm consisted primarily of MgO·Al2O3 and CaO–Al2O3 inclusions. The use of an Al2O3–MgO·Al2O3-lining ladle is more effective in reducing the number density of inclusions in the steel. However, during the refining process, the Al2O3-lining ladle does not have a significant impact on the presence of MgO–Al2O3 and CaO–Al2O3 inclusions in the molten steel. The Al2O3–MgO·Al2O3-lining ladle does not have a significant effect on MgO–Al2O3 inclusions, but it does promote the formation of CaO–Al2O3 and CaS inclusions in the molten steel.

Enhancing attapulgite and cement-modified loess for effective landfill lining: A study on seepage prevention and Cu/Pb ion adsorption

Abstract This study aims to use attapulgite (ATT) and cement to modify loess as the lining material of landfills in loess areas and to exert the adsorption property of modified loess to ensure seepage prevention. It provides a safe, efficient, low-cost anti-seepage material for constructing a landfill in a loess area. For ATT-modified loess, when the content of ATT is less than 10%, the decrease rate of permeability coefficient is obvious, and when the content is more than 10%, the decrease rate becomes slow. After adding 5% cement on this basis, the permeability coefficient of ATT cement-modified loess is 8 × 10−8 cm/s, which meets the standard requirements (≤10−7 cm/s). The results show that the adsorption of Cu and Pb ions on ATT cement-modified loess is higher than that on pure loess. Cu and Pb ions’ adsorption rates are 99.2 and 98.5% in a single solution. In the mixed solution, the adsorption rates of copper and lead ions were 97.5 and 98.2%, respectively. Therefore, the study obtained the ratio of modified loess (85% loess + 10% ATT + 5% cement) that can not only meet the seepage prevention requirements of the landfill but also can adsorb heavy metal ions in the leachate, providing security for the landfill.

A feasibility study of fly ash and bentonite composite mix for assessing its suitability as landfill liner material

A feasibility study of fly ash and bentonite composite mix for assessing its suitability as landfill liner material

Effect of elastomeric filler content on the acoustic and mechanical response of natural fiber-based hybrid composites

The environmental threat of discarded tires needs to be addressed through alternative applications with the enormous increase in the global vehicle population. When tire rubber particles are combined with environmentally friendly, and biodegradable natural fibers in polymer composites, such materials have a lot of potential for use in a variety of applications of insulating structures. The current work explores the effect of adding waste tire rubber particles (TRP) to natural fiber-based hybrid composites, on mechanical and acoustic properties and investigate the possibility of a potential insulating structural material. Tire rubber particles were employed as fillers and chopped banana fibers as reinforcing fibers (particle size less than 400 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}m) with epoxy resin as the matrix in this work. Five compositions were formulated in which the TRP content was varied from 0 to 36 wt.%, compensating for the fiber wt.%. The different compositions prepared by compression molding technique were subjected to compressive, impact, and acoustic characterization. In the natural fiber composites, the compressive strength was observed to dip with increase in TRP content while impact strength was found to rise till 15 wt.% TRP content. Beyond 15 wt.% TRP fillers, the impact strength and brittleness declined. The optimal acoustic response in terms of the sound transmission loss was observed for the composition with 15 wt.% TRP fillers. Polymer composites with natural fiber reinforcing and elastomeric fillers create excellent interior lining materials for buildings, automobiles, and aircrafts, because of their superior mechanical properties and acoustic proofing.

Analysis of the Cooling Modes of the Lining of a Ferroalloy-Casting Ladle

Analysis of the Cooling Modes of the Lining of a Ferroalloy-Casting Ladle

Numerical Analysis of a High-Velocity Projectile’s Impact on Shallow Steel Tunnels in Soft Sandstone

Tunnels are underground infrastructures intended for diverse community applications as well as military applications. During impact loading due to high-velocity projectiles such as ballistic missiles, materials experience a high strain rate. Moreover, there is a superficial augmentation of the dynamic strength when geomaterials such as rock are subjected to a high strain rate. Despite this strength enhancement, tunnels can get damaged by the impact load of a projectile hitting at a high velocity if they are present at a shallow depth. The present study is an effort to comprehend the response of a shallow tunnel in soft sandstone due to the impact load by a ballistic projectile using the FEM-based software ABAQUS/CAE 6.11. The Drucker–Prager damage model and the Johnson–Cook damage model were used to define the properties of the rock mass and steel tunnel lining, respectively. The crown of the 3 m diameter tunnel was kept at different depths from 1 m to 5 m from the surface. A striking velocity of 1000 m/s at a normal position to the target was given to the projectile. The projectile caused noticeable damage to the tunnel lining up to 3 m crown depth. Increasing the crown depth had a positive effect on the maximum depth of the projectile penetration up to 4 m tunnel crown depth, after which the effect reversed, making the tunnel safer. The maximum von Mises stress on the tunnel lining reduced in a logarithmic trend with an increase in the crown depth, gradually lowering to an impact load lesser than the yield stress of the tunnel lining material after a crown depth of 4.5 m.

Staged Z-pinch radiation-hydrodynamic simulations on a 20-MA driver

We report on one-dimensional simulations of a staged Z-pinch (SZP) fusion scheme using the radiation-hydrodynamics code HYDRA [Marinak et al., Phys. Plasmas 8, 2275 (2001)]. A pulsed-power driver, based on the Z-machine at Sandia National Laboratories, with a peak current around 20 MA, is used to implode a high-Z gas liner surrounding a cylindrical DT fuel target. For the best conditions used in this work, excluding some physical processes, such as mix, we find a “clean” fusion yield of 7.05 MJ (2.5 ×1018 neutrons), thus showing the potential for high yields using this scheme. The design achieving this yield was determined through a study of different liner materials, liner masses, and fuel masses. We also address previous simulations of the SZP setup that used ad hoc limits of the total internal energy of the liner that can artificially increase fusion yields.

Structural safety of compressed air energy storage sealing materials

The structural safety of sealing materials is one of the important technical problems of compressed air energy storage. FLAC3D is used to analyze and compare various combination schemes using steel lining and flexible material as sealing materials and evaluate the safety of each scheme, which provides a reference for the design of high-pressure gas storage. The contact surface between the concrete and the steel lining is set up to enhance the relative sliding between them, which is conducive to the coordination of steel plate deformation and the reduction of steel plate stress. The stress of steel plate can be significantly reduced by placing some flexible materials in steel plate and lining concrete, and the lower the modulus of flexible materials is, the better the stress of steel plate structure is.

Cyclic Thermal and Structural Testing of a Hot Particle Storage Bin

Thermal energy storage is a key element in concentrating solar energy systems. In 2017 a Roadmap toward a third-generation system that could meet the SunSHOT goals of 0.06 $/kWe recommended increasing temperatures to > 700° C for heat transfer media to in-crease thermal efficiencies and lower levelized costs of heat. In 2021, the U.S. Department of Energy selected the particle pathway, G3P3, to build a 1 MWt prototype solar tower with 6 MWh thermal energy storage at the NSTTF in Albuquerque, NM. Of the primary components, the falling particle receiver, and particle-to-sCO2 heat exchanger have been demonstrated at the 250 kWt capacity. The storage component is now being demonstrated as part of the G3P3-USA and G3P3-KSA pilot plants. Storage bin liner materials have been demonstrated by KSU in 2016 and 2019. A flowing particle storage container was demonstrated in 2020 by KSU. The testing presented in this work will be the first to test the particle to wall interactions with mono-lithic refractory insulation, and to validate a transient thermal transport model with the unique kinetics of bulk solids in funnel-flow where cooler particles near the walls flow inward toward a hot central flow channel. This work will also de-risk and characterize the specific design of the G3P3-USA storage bin.