Variation Of Material Properties Research Articles

A comprehensive study on static response of agglomerated microstructure-dependent coated functionally graded carbon nanotubes reinforced composite nanoshells rested on complex elastic foundation

An extensive investigation into the bending behavior of nanoshells made of coated functionally graded (FG) carbon nanotubes reinforced composites has been conducted, employing a novel spatial variation in material properties. The study explored Hardcore and Softcore of coated FG nanoshells. The examination includes five distribution patterns: a fully coated tri-directional, two bidirectional patterns, a transverse unidirectional, and an axial unidirectional distribution. The shell is resting on an orthotropic Winkler, Pasternak and Kerr foundations. Galerkin method is employed to establish an analytical solution for the equilibrium equations. This approach is designed to accommodate a variety of different boundary conditions. A comprehensive examination is undertaken to demonstrate the effects of various geometric and material parameters on the deflection and stresses of nanoshells.

A micromechanical nested machine learning model for characterizing materials behaviors of bulk metallic glasses

In the present work, a novel micromechanical data-driven Machine Learning (ML) framework was proposed to characterize material parameters in bulk metallic glasses (BMGs) using nanoindentation simulations with Berkovich and spherical tips. A vast collection of data on material behavior in BMGs during nanoindentation was compiled, utilizing a series of Drucker-Prager model coefficients. The predictive model was constructed using a nested machine learning algorithm, which incorporated hyper-parameters tuning and a principal model. This nested configuration optimized the architecture of a deep neural network, acting as the key estimator for BMG material properties. The outcomes indicated that the ML model proficiently predicted critical material properties, including compressive yield strength, elastic modulus, flow stress ratio, and Poisson ratio. Notably, the ML model exhibited superior accuracy in predicting elastic modulus and compressive strength, suggesting a robust correlation with flexural elasticity and compressive strength. Furthermore, the study highlighted the significance of input feature weight functions, as they strongly influenced the ML model's performance. Each output target's dependence on the individual proportion of input features contributed to the model's adaptability in handling variations in material properties. Finally, the findings of this work contribute to a deeper understanding of the relationships between input features and material properties, facilitating improved predictions of BMG behavior.

Large-scale all-climate vanadium batteries

The vanadium redox flow battery (VRFB) is a highly promising technology for large-scale energy storage applications due to its exceptional longevity and virtually unlimited capacity. However, for this technology to be widely applicable across different geographical locations, a thorough understanding of its all-climate properties is essential. In recent years, VRFBs have been improved by optimising vanadium electrolytes, exchange membranes, carbon fabric electrodes, and casings. However, most research activities have been limited to batteries operating in moderate temperature conditions, and all-climate vanadium batteries are rarely considered. Therefore, this research work focuses on the effect of temperature on the performance of VRFBs. Existing models that deal with the thermal-hydraulic-chemical modelling of VRFBs either ignore the coupling between the governing physical processes or the variation of key material properties with temperature. In this study, we consider both the coupling of the multi-physics processes that influence the behaviour of VRFBs and the variation of their underpinning properties with temperature.

Unified EOS incorporating the finite strain theory for explaining thermo elastic properties of high temperature superconductors, nanomaterials and bulk metallic glasses

In the present research paper, we have proposed a novel EOS, which is based on the concepts of finite strain theories for predicting the thermo elastic properties of various materials viz. bulk metallic glasses, nanomaterials, and high temperature superconductors. Development of the present EOS involved deriving an innovative mathematical framework that considers the effects of finite strain, enabling the prediction of essential properties like pressure and bulk modulus under different compression ratios. For validity and applicability of the proposed EOS, we have conducted an extensive analysis by comparing the calculated thermo elastic properties with existing theoretical models or equation of sates and experimental data available in the literature. The present comparison revealed a remarkable agreement between our predictions and the observed values for a wide range of compression of nanomaterials, bulk metallic glasses, and superconductors. Our research not only introduces a comprehensive equation of state for these advanced materials but also demonstrates its effectiveness in accurately capturing their unique thermodynamic behavior. This present derived EOS can serve as a valuable tool to predict and understand the response of nanomaterials, bulk metallic glasses, and superconductors to varying pressure conditions, aiding the design and development of innovative applications in fields such as materials science, nanotechnology, and condensed matter physics.

Coextrusion of Clay-Based Composites: Using a Multi-Material Approach to Achieve Gradient Porosity in 3D-Printed Ceramics

3D printing of ceramics has started gaining traction in architecture over the past decades. However, many existing paste-based extrusion techniques have not yet been adapted or made feasible in ceramics. A notable example is coextrusion, a common approach to extruding multiple materials simultaneously when 3D-printing thermoplastics or concrete. In this study, coextrusion was utilized to enable multi-material 3D printing of ceramic elements, aiming to achieve functionally graded porosities at an architectural scale. The research presented in this paper was carried out in two consecutive phases: (1) The development of hardware components, such as distinct material mixtures and a dual extruder setup including a custom nozzle, along with software environments suitable for printing gradient materials. (2) Material experiments including material testing and the production of exemplary prototypes. Among the various potential applications discussed, the developed coextrusion method for clay-based composites was utilized to fabricate ceramic objects with varying material properties. This was achieved by introducing a combustible as a variable additive while printing, resulting in a gradient porosity in the object after firing. The research’s originality can be summarized as the development of clay-based material mixtures encompassing porosity agents for 3D printing, along with comprehensive material-specific printing parameter settings for various compositions, which collectively enable the successful creation of functionally graded architectural building elements. These studies are expected to broaden the scope of 3D-printed clay in architecture, as it allows for performance optimization in terms of structural performance, insulation, humidity regulation, water absorption and acoustics.

Vibration analysis of tri-directionally coated plate via thickness-stretching and microstructure-dependent modeling

In this study, the tri-directionally-coated functionally graded plate has different levels of microstructure and is modeled more accurately using nonclassical mechanics incorporating the intrinsic characteristic lengths as well as using a spatial variation of material properties. The free vibration behavior of the tri-directionally-coated functionally graded plate is investigated using a refined quasi-3D higher-order shear deformation theory in conjunction with nonlocal strain gradient theory. Based on the generalized field of displacement, the quasi-3D higher-order shear deformation theory is employed by reducing the number of variables from six to five variables. The equations of motion are performed based on the principle of Hamilton and solved by applying the Galerkin technique to cover various boundary conditions. Besides, the microstructure-dependent parameters, that is, the nonlocal parameter and the length scale parameter, also affect significantly the frequency of the tri-directionally-coated functionally graded plates. The multi-directionally-coated plate is softened when considering the nonlocal parameter; the multi-directionally-coated plate is, however, hardened when considering the length scale parameter.

Strength prediction and stochastic analysis of ultra-high performance concrete columns under the explosive blast load

The performance research based on numerical and experimental studies on ultra-high performance concrete (UHPC) generally considers it as an isotropic material, which is obviously different from what it really is in practical engineering. A database of UHPC compressive strength was investigated, having the same UHPC mix proportion as the field blast experiment, to show how the strength of UHPC varies in compression. It is found that Weibull distribution is the best fit of its probability model. A combination of Monte-Carlo and Finite Element method is used, adopting the available UHPC compressive strength, to reproduce the field blast test on UHPC columns. Both the non-spatial and spatial variability of material properties of the UHPC columns are under consideration to conduct the UHPC column strength prediction under blast loads. The residual loading capacity, damage index and failure mode of UHPC columns with different sizes damaged by different explosion severities are obtained by non-spatial simulation and spatial simulation respectively. It can be concluded that compared with the non-spatial model, the numerical simulation results of the spatial model are closer to the experimental situation. Therefore, inclusion of spatial variability is recommended for reliability-based blast-resistant design for UHPC column.

Numerical and experimental investigation on the heat transfer and mass transport in LPBF in-situ alloying of Al/Cu alloy

PurposeLaser powder bed fusion (LPBF) in-situ alloying is a recently developed technology that provides a facile approach to optimizing the microstructural and compositional characteristics of the components for high performance goals. However, the complex mass and heat transfer behavior of the molten pool results in an inhomogeneous composition distribution within the samples fabricated by LPBF in-situ alloying. The study aims to investigate the heat and mass transfer behavior of an in-situ alloyed molten pool by developing a three-dimensional transient thermal-flow model that couples the metallurgical behavior of the alloy, thereby revealing the formation mechanism of composition inhomogeneity.Design/methodology/approachA multispecies multiphase computational fluid dynamic model was developed with thermodynamic factors derived from the phase diagram of the selected alloy system. The characteristics of the Al/Cu powder bed in-situ alloying process were investigated as a benchmark. The metallurgical behaviors including powder melting, thermal-flow, element transfer and solidification were investigated.FindingsThe Peclet number indicates that the mass transfer in the molten pool is dominated by convection. The large variation in material properties and temperature results in the presence of partially melted Cu-powder and pre-solidified particles in the molten pool, which further hinder the convection mixing. The study of simulation and experiment indicates that optimizing the laser energy input is beneficial for element homogenization. The effective time and driving force of the convection stirring can be improved by increasing the volume energy density.Originality/valueThis study provides an in-depth understanding of the formation mechanism of composition inhomogeneity in alloy fabricated by LPBF in-situ alloying.

Magnetic porous carbon material derived from imine-linked covalent organic frameworks for magnetic solid phase extraction of trace chlorine-containing herbicides in soil

Here, imine-linked covalent organic frameworks coated Fe3O4 microspheres were fabricated and employed as the self-template to prepare magnetic porous carbon material. The magnetic solid phase extraction (MSPE) performance of such magnetic covalent organic frameworks derived porous carbons (CMCOFs) were studied for the first time, and the improved MSPE performance was verified. The variations of chemical and material properties in the carbonization processes were studied, and it was found that the CMCOFs carbonated at 400°C exhibited highest adsorption efficiencies for chlorine-containing herbicides due to the formation of nitrile components at this stage. The CMCOFs retained high adsorption efficiencies (above 90 %) to chlorine-containing herbicides at wide pH range (3–12) and high salt concentration. The CMCOFs-based MSPE coupled with HPLC technique was in good potential for analysis of trace chlorine-containing herbicides in soil samples. Under the optimized conditions, this approach displayed short extraction and elution time (5 and 8 min) and low limits of detection (0.35–5.5 ng/mL) for chlorine-containing herbicides. The recoveries of spiked analytes and the relative standard deviations in real soil samples were 81.86 %–110.9 % and less than 5.92 %, respectively. This study provides an efficient method for the analysis of trace chlorine-containing herbicides in complex samples, as well as give some inspiration on material modulation by controlled carbonization to achieve improved sorption performances.

The iron melting point determination by 2D simulation

In the past research, molecular simulation has been widely used to simulate various properties of materials and understand atomic theory. The effect of the material’s surface tension and different closed-packed structures can also be successfully simulated by using the Lennard-Jones potential. However, the two-dimensional simulation of the iron’s melting point has not been studied deeply. Thus, by MATLAB, this project used the Lennard-Jones potential and 2D simulation to simulate the melting point of the iron (698.82 K-725.08 K) under certain pressure. This pair coefficient equation of the iron atom from 300K to 900K was found successfully. The pair coefficient equation is generally in line with expectations, but the calculated melting point is far away from the experimental result (1811 K). This is mainly because of the limitation of 2D simulation. (the vertical force is not contained) The advice for the future study is to use the 3D simulation to do the more accurate iron’s melting point calculation.

Root size effects on transverse root-soil interactions

For smaller lateral plant roots in coarse-grained soils, a potentially large relative size of soil particles compared to the roots may affect their transverse resistance. Even for the larger roots of trees, particle size effects may be important, e.g. when testing 1:N reduced scale models in a geotechnical centrifuge. The Discrete Element Method (DEM) was used to investigate this problem. A rigid lateral root segment under transverse loading in plane strain was simulated and compared with Finite Element Method (FEM) simulations, where the soil was modelled as a continuum (no particle size effects). Even at the lower root/particle diameter ratios (dr/D50) investigated (6 to 21), particle size effects on transverse capacity were negligible upon push-in, while during uplift, they were observed for dr/D50 < 8, arising from the dimension of the uplifted soil volume above the root. The material properties of roots are also typically diameter dependent. Further simulations of long flexible roots subject to end rotation were performed employing a beam-on-non-linear-Winkler-foundation approach, using p-y curves obtained from the DEM or FEM simulations. Compared with particle-size related effects, diameter-dependent variation of material properties had a much larger controlling effect on root capacity and stiffness as relevant for plant/tree overturning.

Improved mechanical and tribological properties of TiAlN coatings by high current pulsed electron beam irradiation

High current pulsed electron beam (HCPEB) irradiation is an important surface engineering technique, which has been proved to be valid in modifying the surface microstructure and properties of various materials. In this work, HCPEB was employed to irradiate TiAlN coatings. The microstructure, mechanical and tribological properties of both original and irradiated TiAlN coatings were investigated. The results showed that the surface roughness of the TiAlN coatings first increased with 5 pulses of HCPEB irradiation, and then gradually declined with a further increase in pulse numbers. Compared with the original coating, the coating irradiated by 15 pulses demonstrated superior hardness (up to 33.4 GPa) and adhesion strength (112N), excellent wear resistance (wear rate of 3.3 × 10−6 mm3/Nm) and low friction coefficient (0.37). It is believed that the grain refinement, formation of the transition zone and adjustment of residual stresses after 15 pulses of HCPEB treatment are responsible for the improvement in both mechanical and tribological properties of the TiAlN coatings. These findings might suggest the potential applications of HCPEB irradiation for surface modification and hardness improvement of hard nitride coatings.

Analisis Geoteknik Ditinjau dari Karakteristik Kuat Geser Material Longsoran

This research aims to analyze geotechnical aspects in the context of slope stability and soil landslides. The main focus of this research is on the shear strength characteristics of materials, which are a key factor in predicting the potential for landslides. The methods used in this research involve field geotechnical data collection, laboratory testing to determine geotechnical parameters, and numerical modeling to analyze slope stability. The research results indicate that the shear strength of landslide materials is a crucial factor in evaluating slope stability. Variations in geotechnical properties of materials, such as water content, soil texture, and density, have a significant impact on shear strength and the potential for landslides. Additionally, numerical analysis shows that environmental factors, such as rainfall and human activities, can also influence slope stability. This research provides a better understanding of the relationship between shear strength characteristics of materials and slope stability, serving as a basis for the development of landslide risk mitigation strategies. This has important implications for disaster management and safe land use planning in landslide-prone areas.

Exploring the internal textures and physical properties of digitate sinter in hot springs: Implications for remote sampling on Mars

Hydrothermal silica deposits on the surface of Mars with textures analogous to terrestrial hot spring deposits are, arguably, one of the best potential targets in the search for evidence of life beyond Earth. Here we investigate terrestrial hot spring digitate silica structures (modern: El Tatio, Chile; Mars Pool at Rotokawa geothermal area, and Te Kopia thermal stream, New Zealand; 1.6–1.8 ka: Opal Mound, Utah, U.S.A.), which are texturally and mineralogically analogous to martian deposits in the Columbia Hills of Gusev crater, in order to elucidate how their physical properties vary with depositional environment, and to help guide future remote sampling endeavors. Micro-computed tomography allows visualization of the internal texture of geological materials through variations in porosity and relative density, and is demonstrated here as a key, non-invasive technique for investigating future returned planetary samples. Bulk porosity, associated with pore sizes greater than >1–2 μm, varies from 4.7 to 21.3% in the four studied terrestrial digitate sinter samples, representing a range of fluid pHs of formation. Moreover, density variations between laminae largely reflect a nano-scale porosity (<1–2 μm) controlled by silicification of microbial material and/or recrystallization due to incipient diagenesis. Nano-indentation measurements of the digitate structures reveal variations in hardness and the reduced Young's modulus. The hardness of opal-A in modern digitate sinter varies, on average, from 2 to 4 GPa (El Tatio, Mars Pool, Te Kopia), but hardens with incipient diagenesis to >6 GPa (Opal Mound). Regions of nano-porous silica in all samples reduces the hardness in these areas to <1 GPa. No significant variation in material properties can be correlated to different fluid chemistries of the modern samples. Collectively, these results imply that the preservation of silicified microbes in digitate sinter structures should lead to a decrease in material hardness and elastic modulus owing to higher porosity in microbial laminae, whereas recrystallization of opal-A or secondary fluid precipitation will lead to hardening. For future remote sampling on Mars, the range of material properties of siliceous materials must be considered when designing appropriate sampling devices, as martian materials both harder and softer than accounted for in the design process may create sampling challenges.

Quantile Loss Function Empowered Machine Learning Models for Predicting Carotid Arterial Blood Flow Characteristics

This research presents a novel approach using machine learning models with the quantile loss function to predict blood flow characteristics, specifically the wall shear stress, in the common carotid artery and its bifurcated segments, the internal and external carotid arteries. The dataset for training these models was generated through a numerical model developed for the idealized artery. This model represented blood as an incompressible Newtonian fluid and the artery as an elastic pipe with varying material properties, simulating different flow conditions. The findings of this study revealed that the quantile linear regression model is the most reliable in predicting the target variable, i.e., wall shear stress in the common carotid artery. On the other hand, the quantile gradient boosting algorithm demonstrated exceptional performance in predicting wall shear stress in the bifurcated segments. Through this study, the blood velocity and the wall shear stress in the common carotid artery are identified as the most important features affecting the wall shear stress in the internal carotid artery, while the blood velocity and the blood pressure affected the same in the external carotid artery the most. Furthermore, for a given record of the feature dataset, the study revealed the efficacy of the quantile linear-regression model in capturing a possible prevalence of atherosclerotic conditions in the internal carotid artery. But then, it was not very successful in identifying the same in the external carotid artery. However, due to the use of idealized conditions in the study, these findings need comprehensive clinical verification.

Air and hydrogen injection tests on saturated compacted bentonite

Air and hydrogen injection tests on saturated compacted bentonite

Preface

National Conference on Physics and Chemistry of Materials-2023Research in materials science helps in understanding the physical and chemical properties of various materials. It enables scientists and researchers to develop materials for a wide range of applications. The National Conference on Physics and Chemistry of Materials (NCPCM) has been organised by the Department of Physics, Govt. Holkar (Model Autonomous) Science College, Indore, once every two years. This conference provides an ideal platform and opportunity to share research ideas with eminent scientists, academicians, industrialists, and policymakers working in the various fields of science and technology. This conference covers various fields of the physics and chemistry of materials, such as nanomaterials and thin film technology, condensed matter physics, computational physics, materials chemistry, etc.NCPCM-2023 was conducted in hybrid mode. About 200 participants from various research institutions, universities, colleges, and industries across the globe have attended the conference and presented research papers in physical sessions and online through video conferencing or MOOC-based methods in the form of keynote lectures, invited talks, and oral presentations in parallel sessions of different categories. All papers selected for the proceedings have been reviewed through scientific processes to maintain the scientific standards of the NCPCM and IOP publishing partner.The articles are selected for publication by the editors based on the recommendations of qualified reviewers.We hope that the National Conference on Physics and Chemistry of Materials, 2023, will foster new collaborations, generate innovative ideas, and inspire the next generation of materials scientists and researchers. Through the transformative power of physics and chemistry in materials science, let us press the boundaries of knowledge, explore uncharted territories, and create a brighter future.We extend our heartiest thanks to all the participants, keynote speakers, invited speakers, members of the advisory committee, organising committee, technical coordinators, session chairs, judges, reviewers, and all supporting staff for their herculean support. We also acknowledge the financial support from the Madhya Pradesh Council of Science and Technology (MPCST), Bhopal.Indore, 31 May 2023List of Editors, Advisory Committee, Conference Committeem, Organizing Committee, Local Adversary Committee, Technical Co-Ordinators are available in this Pdf.

Tomographic optical emission spectroscopy of an atmospheric pressure plasma jet and surface ionization waves on planar and structured surfaces

In this paper, an approach for 3D plasma structure diagnostics using tomographic optical emission spectroscopy (Tomo-OES) of a nanosecond pulsed atmospheric pressure plasma jet (APPJ) is presented. In contrast to the well-known Abel inversion, Tomo-OES does not require cylindrical symmetry to recover 3D distributions of plasma light emission. Instead, many 2D angular projections are measured with intensified cameras and the multiplicative algebraic reconstruction technique is used to recover the 3D distribution of light emission. This approach solves the line-of-sight integration problem inherent to optical diagnostics, allowing recovery of localized OES information within the plasma that can be used to better infer plasma parameters within complex plasma structures. Here, Tomo-OES was applied to investigate an APPJ operated with helium in ambient air and impinging on planar and structured dielectric surfaces. Surface charging caused the guided streamer from the APPJ to transition to a surface ionization wave (SIW) that propagated along the surface. The SIW experienced variable geometrical and electrical material properties as it propagated, leading to 3D configurations that were non-symmetric and spatially complex. Light emission from He, N, and N2 were imaged at ten angular projections and the respective time-resolved 3D emission distributions in the plasma were then reconstructed. The spatial resolution of each tomographic reconstruction was 7.4 µm and the temporal resolution was 5 ns, sufficient to observe the guided streamer and the effects of the structured surface on the SIW. Emission from He showed the core of the jet and emission from N and N2 indicated effects of entrainment of ambient air. Penning ionization of N2 created a ring or outer layer of N that spatially converged to form the ‘plasma bullet’ or spatially diverged across a surface as part of a SIW. The SIW entered trenches of size 150 µm, leading to decreases in plasma light emission in regions above the trenches. The plasma light emission was higher in some regions with trenches, possibly due to effects of field enhancement.

Modeling of frontal polymerization of carbon fiber and dicyclopentadiene woven composites with stochastic material uncertainty

A novel finite element modeling framework is proposed for simulating dicyclopentadiene (DCPD) frontal polymerization in carbon fiber (CF) woven composites. A mesoscale CF/DCPD representative volume element (RVE) model was developed with two triggering directions, resulting in out-of-plane and in-plane DCPD polymerization. The Arrhenius equation coupled with a modified Prout-Tompkins autocatalytic model was used to evaluate the dynamic DCPD polymerization process. The rate and degree of DCPD cure were calculated by the material property uncertainties of DCPD with and without random void inclusions (3 % used as a reference in this work). The DCPD frontal polymerization in CF/DCPD composite was strongly influenced by the triggering direction. In the RVE model considered in this work, DCPD frontal polymerization was slightly faster in the in-plane (warp/weft yarn) directions than the out-of-plane (thickness) direction; polymerization occurs first in DCPD resin and is followed by CF/DCPD interface. Material property uncertainty and void inclusion had significant effects on both out-of-plane and in-plane DCPD polymerization. A large variation in DCPD material properties and the presence of void inclusions significantly delayed the rate and degree of DCPD frontal polymerization. This work provides the preliminary estimation of the frontal polymerization of DCPD-based composites and guides the structural applications of these materials.

Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation

The presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical behaviour of a living human abdominal wall is important for the proper design of surgical meshes used for ventral hernia repair, which was also a motivation for the research presented below.The research refers to the strain field of a loaded abdominal wall and presents the evolution of principal strains and their directions in the case of 12 subjects, 8 male and 4 female. Peritoneal dialysis procedure allows for the measurement of intra-abdominal pressure after fluid introduction.High variability among patients is observed, also in terms of principal strain direction. Subjects exhibit intra-abdominal pressure of values from 11 to 21 cmH2O. However, the strain values are not strongly correlated with the pressure value, indicating variability of material properties.