Material Properties Research Articles

THERMOMECHANICAL COUPLED MODEL OF COATING SYNTHESIS ON A SUBSTRATE

Among modern combined laser and electron-beam technologies, special attention is paid to those in which composition formation takes place directly in the process of product creation or coating synthesis. In the present work, a coupled model of coating synthesis on a substrate is constructed. When building the model, a sequential transition was carried out from a three-dimensional model of the coating synthesis process on the substrate to a one-dimensional model, which is useful for qualitative analysis. The one-dimensional model takes into account the main physical features of the physical and chemical processes during the synthesis, as well as the coupled nature of the heat transfer and deformation at the same time taking into account the differences in thermophysical and mechanical properties of different materials. When constructing the intermediate analytical solution, it is assumed that the system "substrate-coating" is in a plane stress state. As a result, explicit expressions for the components of stress and strain tensors connected with changes in temperature and composition are obtained. With the help of the obtained analytical solution, the thermokinetic part of the problem is modified and reduced to a more convenient form. Further, the experience accumulated in the field of macrokinetics is used, which allows us to model the processes of creating new materials (e.g., intermetallic or metal matrix composites) in modern technologies from the point of view of controlling the processes of phase formation in the reaction zone by a moving external source. The transition to dimensionless variables revealed complexes and parameters representing relations of characteristic scales of different processes. The parametric study of the model allowed us to establish interesting qualitative effects. It is demonstrated that the quasi-stationary regime is accompanied by physical and chemical processes in the region, which the laser beam had left, due to the heat accumulated in the materials. It is shown that the coupled nature of different processes significantly affects the dynamics of synthesis and the parameters of the quasi-stationary regime.

Nanotechnology in prosthodontics – Small particles big impact

Nearly every aspect of research and development has been significantly impacted by nanotechnology. Notably, nanotechnology is also having an impact on the fields of health and dentistry by utilising its enormous potential. When compared to bulk material, nanoparticles have proven to be far more powerful. Because of its unusual size, it is much easier to change and improve a variety of features, including surface chemistry, charge, bonding ability, and different biological properties. Richard P. Feynman, a late Nobel Prize-winning physicist, developed the idea in 1959. The area was researched in the years that followed for the creation of nanoscale devices and nanosized particles to produce improved qualities. Regularly used dental materials with limitations of inferior physical and biologic qualities can be changed with nanoparticles to improve the material's inherent properties while staying within budgetary constraints. Unique qualities of a nanoscale material may not only have a significant impact on its biological properties, such as cytotoxicity and biocompatibility, but also on its physical properties, such as tensile strength, fracture resistance, and surface hydrophobicity.

Development and microstructural characterization of ultra-lightweight aggregate concrete incorporating different sizes of polypropylene fibers

In this study, ultra-lightweight concrete with an oven-dry density of 800 kg/m3 was produced using expanded glass as the lightweight aggregate. Polypropylene fibers of different sizes were incorporated into the specimens to examine their effects on the material properties, such as drying shrinkage and flexural strength. The target dry density was achieved by applying the packing density concept to optimize the mix grading and calculate the content of each concrete component. Specimens with different ratios of short and long fibers were produced. Their fresh state, mechanical performance, and physical properties were extensively analyzed using various methods, including X-ray micro-computed tomography to examine the microstructure. The experimental results indicated a significant reduction in drying shrinkage for the fiber incorporated specimens, dependent on the fiber length and content. The compressive strength of the specimens exceeded 12 MPa. Moreover, the inclusion of polypropylene fibers notably enhanced the flexural strength by approximately 60%, while the lower density contributed to substantially reduced thermal conductivity by up to 26%, which is beneficial for thermal insulation. These results confirm that polypropylene fibers can be used to produce ultra-lightweight concrete with self-leveling properties, without compromising mechanical and physical performance.

Оценка качества и механических свойств получаемых слоев металла из низкоуглеродистой стали методом WAAM с использованием дополнительной механической и ультразвуковой обработки

Introduction. Additive manufacturing is a technology that enables three-dimensional (3D) components to be printed layer by layer according to digital models. Completely different from traditional manufacturing methods such as casting, forging, and machining, additive manufacturing is a near net shape manufacturing process that can greatly enhance design freedom and reduce manufacturing runtime. The material processing challenges in Wire and Arc Additive Manufacturing (WAAM) are related to achieving performance metrics related to geometric, physical, and material properties. Tight tolerances and stringent surface integrity requirements cannot be achieved by utilizing stand-alone AM technologies. Therefore, WAAM parts typically require some post-processing to meet requirements related to surface finish, dimensional tolerances and mechanical properties. It is therefore not surprising that the integration of AM with post-processing technologies into single and multi-setup machining solutions, commonly referred to as hybrid AM, has become a very attractive proposition for industry. The purpose of the work is to evaluate the quality and mechanical properties of the resulting metal layers of mild steel by WAAM method using additional mechanical and ultrasonic processing. Research Methods. To conduct the experiments, a set of welding equipment was used — a single-phase inverter device KEMPPI Kempomat 1701, designed for welding with wire in shielding gases. A mixture of argon and carbon dioxide (80 % argon and 20 % CO2) was used as a shielding gas. SV-08G2S (0.8 C-2 Mg-Si) wire was used as the surfacing material. A plate made of steel St3 with overall dimensions 150×100×5 mm was used as a base for surfacing. The surface of the plate before surfacing was thoroughly cleaned from the layer of oxides, oil, rust and other contaminants. For this purpose mechanical cleaning of the surface was used with BOSCH abrasive wheel with a diameter of 125 mm diameter and a grit size of 120. Before surfacing the surface of the product was degreased with white spirit. The gas flow rate was set at 8 dm3/min. To select the optimal wire feed rate and volt-ampere characteristic, surfacing was performed at each adjustment step of wire feed rate, and voltage. Mechanical statistical tensile tests, chemical composition analysis and metallographic studies were also performed. Results and Discussion. Gas porosity is a typical defect that occurs during the WAAM process and should be eliminated because it adversely affects the mechanical properties. Initially, gas porosity leads to a reduction in the mechanical strength of the part due to damage from microcrack formation. In addition, it often causes the surfaced layer to have worse fatigue properties due to the spatial distribution of different shape and size structures. In our experiments we found that a wire feed speed range of 5–6 m/min is optimal. Increasing the flow rate of shielding gas in the range of 8–14 l/min allows reducing porosity in the surfaced metal to almost zero. The mechanical properties of the surfaced beads show that the average value of yield strength after machining is higher than that of unprocessed specimens. The data obtained from these experiments are in good agreement with those reported in the literature. The presented results can be used in real WAAM technological processes.

Study on the Macro-/Micrometric Characteristics and Mechanical Properties of Clayey Sandy Dredged Fill in the Guangdong Area

The study of dredged fill in Guangdong (GD), China, is of great significance for reclamation projects. Currently, there are relatively few studies on dredged fill in Guangdong, and there are many differences in the engineering characteristics of dredged fill foundations formed through land reclamation and natural foundations. In order to have a more comprehensive understanding of the physico-mechanical properties of blowing fill in the coastal area of GD and to understand the effect of its long-term creep row on the long-term settlement and deformation of buildings, the material properties, microstructure, elemental composition, triaxial shear properties, and triaxial creep properties of dredged fill in Guangdong were studied and analyzed through indoor geotechnical tests, scanning electron microscopy (SEM), X-ray diffraction (XRD), and conventional triaxial shear tests and triaxial creep tests. The test results showed that the Guangdong dredged fill is characterized by a high water content, high pore ratio, and high-liquid-limit clayey sand, and the mineral composition is dominated by quartz and whitmoreite. The scanning electron microscopy results showed that the particles of the dredged fill showed an agglomerated morphology, and the surface of the test soil samples had scaly fine flakes and a fragmented structure. In the triaxial shear test, the GD dredged fill showed strain hardening characteristics, and the effective stress path showed continuous loading characteristics; the consolidated undrained shear test showed that the GD dredged fill had shear expansion characteristics under low-perimeter-pressure conditions. It was found that, with an increase in bias stress, the axial strain in the consolidated undrained triaxial creep test under the same perimeter pressure conditions gradually exceeded the axial strain in the consolidated drained triaxial creep test. The results of this study are of theoretical and practical significance for further understanding the mechanical properties of silty soils in the region and for the rational selection of soil strength parameters in practical engineering design.

Optimization of the Skanavi model and its application to high permittivity materials

Abstract In this paper, a novel method is introduced to optimize the traditional Skanavi model by decomposing the electric field of molecules into the electric field of ions and quantitatively describing the ionic-scale electric field by the structural coefficient of the effective electric field. Furthermore, the optimization of the Skanavi model is demonstrated and the ferroelectric phase transition of BT crystals is revealed by calculating the optical and static permittivities of BaTiO3, CaTiO3, and SrTiO3 crystals and the structure coefficients of the effective electric field of BT crystals after Ti4+ displacement. This research compensates for the deficiencies of the traditional Skanavi model and refines the theoretical framework for analyzing dielectric properties in high permittivity materials.

Nondestructive Testing of Polymer Aging Based on Room-Temperature Phosphorescence.

Polymeric room-temperature phosphorescence (RTP) materials have attracted much attention due to their advantages of easy processing and excellent luminescent properties. However, it is still a challenge to obtain industrial production grade material through simple and green processing strategies. Herein, through the codoping strategy, different phosphors were embedded into nylon, a kind of polymer matrix, to obtain a series of highly efficient RTP materials without any organic solvents, for which the phosphorescence lifetime and brightness could reach 628.8 ms and 14 cd/m2, respectively. Besides, we found that the photophysical properties of these RTP materials varied greatly among different types of nylon matrix, owing to the divergence in the number of hydrogen bonding "sites". The superiority of the injection molding processing strategy enables the preparation of RTP materials to achieve desolvation, which could also be processed into any complex and desiring shape. Significantly, nylon can affect molecular chain changes due to aging and other problems, so that these RTP materials are considered as potential nondestructive testing for nylon product aging levels. This strategy also paves the way for the development of large-scale, eco-friendly, and practical application RTP materials and provides new ideas to industrialized preparation of long-lived RTP materials in the future.

Enhancing Sustainable Road Construction: Evaluation of the Mechanical and Durability Properties of Stabilized Earth-Based Pavement Materials

The materials traditionally used in the construction of flexible and rigid pavements in modern road infrastructure present challenges in achieving sustainable development goals. Advances in technology have introduced the use of different pavement material mixes, leading to the introduction of earth-based alternatives. These materials are environmentally friendly, cost-effective, recyclable, and offer excellent insulation properties. Stabilization of earth-based materials improves their mechanical properties, reducing road construction costs and increasing durability. The present study investigates the mechanical and durability properties of earth-based materials stabilized with various additives, including cement, lime, polymer, and biopolymer, over 28 and 56 days. Fresh properties are assessed using unit volume weight, flow table, air content, and fall cone tests, while hardened properties are assessed using flexural strength, compressive strength, and water absorption. Microstructural analysis is carried out using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The cement-stabilized samples show improved strength and durability, with the 5% cement group showing a 67% increase in compressive strength over the control group and the 10% cement group showing over 200% higher compressive strength. These results suggest that stabilized earth-based materials could provide a cost-effective and sustainable alternative to conventional pavements for low-traffic roads.

Investigation of the Method for Measuring the Surface Property Parameters of Variable Charge Minerals Using Ion Selection Electrode

In this study, the surface property parameters of non-swelling variable charge minerals, kaolinite and goethite, were determined using the ion-selective electrode method. The effects of experimental conditions, such as pH, ion concentration ratio, and liquid addition method, on the measurement results were clarified to provide a reference for accurately assessing the surface properties of variable charge materials. The research employed ion adsorption equilibrium experiments under varying pH levels, ion concentration ratios, and liquid addition methods. A combined surface property analysis was conducted using K+ and Ca2+ as indicator ions to characterize surface parameters. The results were compared with the specific surface area obtained via the BET method to verify accuracy, thereby identifying optimal measurement conditions. The study led to the following five conclusions. (1) pH significantly affected the adsorption amount and ratio of indicator cations, thereby influencing the accuracy of surface property parameters. (2) The addition method and concentration ratio of electrolytes influenced the measurement accuracy by affecting the adsorption state and equilibrium time of the two indicator cations. (3) For kaolinite, the optimal initial pH ranged from 7.5 to 8.5 in the KOH + Ca(OH)2 system and from 8.0 to 8.5 in the KOH + CaCl2 system, while the equilibrium pH was 7.5 to 8.0 in both systems. The optimal ion concentration ratios were cK:cCa = 2:1 and 9:1, respectively. (4) For goethite, the optimal initial and equilibrium pH values were 8.5 to 9.0 and 7.5 to 8.0, respectively, in both KOH + Ca(OH)2 and KOH + CaCl2 systems. The optimal ion concentration ratios were 4:1 and 20:1, respectively. (5) Through comparison, the optimal initial pH for measuring the two variable charge minerals was determined to be 8.5 ± 0.1, with the optimal equilibrium pH at 7.5 ± 0.1. However, the concentration ratios varied significantly, suggesting the need for systematic research by adjusting a series of ion concentration ratios based on the initial pH.

Aligning and Observing the Liquid Crystal Director in 3D Using Small Magnetic Fields and a Wedge‐Cell

AbstractThe mechanical and optical properties of liquid crystalline materials are largely dependent on the director profile. More complex soft robotic functions and programmed optical properties require spatially varying director profiles, ideally in 3D. However, it is challenging to achieve arbitrary director orientation with most established alignment techniques, as one needs to overcome surface interactions, use high electric or magnetic field strengths and temperatures. Another experimental difficulty is that there is a lack of suitable techniques that can be used to characterize the director in 3D. Here, this study first shows that the addition of 5CB to reactive mesogens permits cross‐linked liquid crystalline materials to be fabricated with a spatially varying 3D director profile using weak magnetic fields (0.13 T). This study also shows, how these can be characterized with an optical technique that uses a wedge cell to visualize the programmed 3D director profile. Interestingly, the method also permits the real‐time observation of the director. This work shows that it is possible to precisely control the director in 3D with low magnetic fields and that the dynamics can be directly observed, which facilitates potential applications of soft liquid crystalline (LC) gels and potentially also elastomers.

Perovskite in Triboelectric Nanogenerator and the Hybrid Energy Collection System

In the context of escalating energy demands and environmental sustainability, the paradigm of global energy systems is undergoing a transformative shift to innovative and reliable energy-harvesting techniques ranging from solar cells to triboelectric nanogenerators (TENGs) to hybrid energy systems, where a fever in the study of perovskite materials has been set off due to the excellent optoelectronic properties and defect tolerance features. This review begins with the basic properties of perovskite materials and the fundamentals of TENGs, including their working principles and general developing strategy, then delves into the key role of perovskite materials in promoting TENG-based hybrid technologies in terms of energy conversion. While spotlighting the coupling of triboelectric–optoelectronic effects in harnessing energy from a variety of sources, thereby transcending the limitations inherent to single-source energy systems, this review pays special attention to the strategic incorporation of perovskite materials into TENGs and TENG-based energy converting systems, which heralds a new frontier in enhancing efficiency, stability, and adaptability. At the end, this review highlights the remaining challenges such as stability, efficiency, and functionality for applications in TENG-based energy-harvesting systems, aiming to provide a comprehensive overview of the current landscape and the prospective trajectory of the role of perovskite materials in TENG-based energy-harvesting technologies within the renewable energy sector.

MICROHARDNESS OF SINGLE CRYSTALS OF Ag7+x(P1-xGex)S6 SOLID SOLUTIONS

Superionic conductors have a number of important characteristics and applications that make them important in the field of materials science, technology and industry. At the same time, when developing and analyzing the properties of new materials to optimize their composition and material processing, information about microhardness is mandatory. This is important to ensure the stability and efficiency of devices over a long period of time. This paper presents a study of the microhardness of single-crystal samples of Ag7+x(P1-xGex)S6 (x = 0, 0.1, 0.25, 0.33, 0.5, 0.75, 1) solid solutions. For all the studied samples, a decrease in the microhardness H is observed with an increase in the load P, indicating the presence of a direct size effect. The microhardness of single-crystal samples is also described within the PSR (proportional specimen resistance) model, the results of which also indicate the presence of a direct size effect. The values of the intrinsic hardness H0 calculated within the PSR model for solid solutions of Ag7+x(P1-xGex)S6 (x = 0, 0.1, 0.25, 0.33, 0.5, 0.75, 1) are as follows: 903.1 N/mm2 (x=0), 997.7 N/mm2 (x=0.1), 990.2 N/mm2 (x=0.25), 1019.9 N/mm2 (x=0.33), 1053.3 N/mm2 (x=0.5), 1097.8 N/mm2 (x=0.75), 1081.1 N/mm2 (x=0.1). To assess the influence of the direct size effect, Meyer's law was used. For the studied solid solutions of Ag7+x(P1-xGex)S6, the values of the Meyer's index are in the range n = 1.72 ÷ 1.86, which indicates that these solid solutions belong to soft materials.

Characterization and Analysis of Mechanical and Morphological Properties of Hybrid Composite Material from Prosopis Juliflora and Phoenix Sylvestris for Engineering Applications

The demand for sustainable, high-performance materials has driven interest in natural fiber-based composites. This research investigates the development of a hybrid composite using fibers from Prosopis Juliflora and Phoenix Sylvestris combined with glass fibers and epoxy resin. The natural fibers underwent a 10% NaOH treatment to enhance their mechanical properties. Hand layup techniques were employed to fabricate the samples, followed by comprehensive mechanical testing, including tensile, flexural, impact, hardness, and delamination tests. The composite, composed of 60% natural fibers, and 30% resin, and treated with NaOH, exhibited superior mechanical performance, surpassing similar composites in literature. Scanning electron microscopy (SEM) analysis revealed improved fiber-matrix adhesion, while wear testing indicated potential applications in brake linings. The results suggest this hybrid composite offers a viable, sustainable alternative for high-performance engineering applications, particularly in the automotive industry.

B─C Bonding Configuration Manipulation Strategy Toward Synergistic Optimization of Polarization Loss and Conductive Loss for Highly Efficient Electromagnetic Wave Absorption

AbstractIn non‐metallic atom‐doped carbonaceous materials, the disparity in electronegativity between the doped constituents and carbon atoms predetermines the bonding topology of covalent bonds and the distribution of electron density. This, consequently, influences the polarization and electron transport behavior within the doped domain and the electromagnetic wave attenuation attributes of the carbonaceous material. However, the influence of covalent bonds formed by doping with weakly electronegative atoms on electron density distribution, polarization effects, and electromagnetic wave attenuation remains uncharted. To address this deficiency, this study fabricates a porous carbonaceous material (NCP) and incorporates boron‐doped atoms to form a material with tunable B─C bonding configurations (B‐NCP). By modulating the B─C bonding configuration and proportion, it is feasible to achieve the synergistic optimization of conductive loss and polarization loss of the B‐NCP specimen. The optimized prototype B‐NCP‐1200 sample displays exceptionally efficient electromagnetic wave absorption capabilities with a minimum reflection loss (RLmin) of −52.03 dB and an effective absorption bandwidth (EAB) of 5.36 GHz. This study presents a conscientious model for comprehending the electromagnetic attenuation mechanisms associated with weakly electronegative atom doping in carbon‐based electromagnetic wave‐absorbing materials.

Single ion effect on material and electrical properties of deposited and annealed Al2O3 film on 4H-SiC by atomic layer deposition

Abstract It is preferable for the use of highly radiation tolerant SiC devices in space applications due to the strong covalent bond of SiC material. In particular, the MOS devices using SiO2 as a gate dielectric still exhibits a high density of interface states, which enables huge difficulties in accounting for the formation of latent gate damage generated along the heavy ion incidence path. High-k materials represented by Al2O3 gate dielectric offer the most promise to replace the current SiO2 gate dielectric. Al2O3 is a promising high-k material for application in radiation-resistant gate dielectrics on 4H-SiC. The effects of heavy ion irradiation via linear energy transfer (LET) of 99.8 MeV·cm²/mg Bi ions on the surface morphology and interfacial properties of Al2O3 gate dielectric on 4H-SiC were investigated and demonstrated by various characterization methods. It is found that the uniformity of refractive index of 1100 °C annealed Al2O3 films is less affected by radiation compared to as deposited films. Also, the roughness of Rq for the annealed films is varied from 0.28 nm to 0.34 nm before and after irradiation, which shows less degree of increment as compared to as deposited films with increase from 0.24 nm to 0.54 nm. The bombarded pores can be hardly observed in annealed Al2O3. Additionally, the formation of oxygen vacancies or interstitial oxygen contributes to a decrease of Al-O and Al-O-Si bonds after irradiation. Fortunately, the crystallized Al2O3 induced by annealing exhibits a more robust and stable bonding between Al and O and shows less damaged elemental components. These film characterization and underlying mechanisms behind heavy ion irradiation is of meaningful use for development of SiC metal-oxide-semiconductor field effect transistor (MOSFET) irradiation hardening process.

Gradient Luminescence Enhancement in Organic Metal Halide Perovskites via the Suppression of [SbCln]3-n Unit Distortion.

Intrinsic stereochemical activity of the 5s2 electron configuration in Sb3+ leads to structural distortion within [SbCln]3-n units, which, while stabilizing the material, paradoxically diminishes luminescence intensity due to induced asymmetry. To address this issue, a strategy, which encompasses increasing the structural dimensions and introducing In3+ doping, was developed to mitigate the geometrical distortion in the [SbCln]3-n units within the metal-organic perovskite (DABCO)2Sb2Cl10·H2O and (DABCO)2SbCdCl9·2H2O (DABCO = triethylenediamine). This dimensional augmentation confines lattice distortion effectively, and the In3+ doping modifies the 5s2 electron configuration of Sb3+, thereby reducing the distortion at its origin. The unique suitability of indium-based halides as a matrix for Sb3+ doping is underscored by our approach, which capitalizes on their ability to regulate the electron configuration of Sb3+. This strategy has been validated through crystallographic data from single-crystal X-ray diffraction. By effectively reducing the adverse effects of geometric distortion, several hundred-fold enhancements in the luminescent intensity of the material have been achieved by our methodology, leading to potential applications in white-light LEDs. This advancement not only highlights the pivotal role of structural symmetry in the optical properties of materials but also exemplifies the power of material engineering to optimize the optical performance.

Voltage Mining for (De)lithiation-Stabilized Cathodes and a Machine Learning Model for Li-Ion Cathode Voltage.

Advances in lithium-metal anodes have inspired interest in discovery of Li-free cathodes, most of which are natively found in their charged state. This is in contrast to today's commercial lithium-ion battery cathodes, which are more stable in their discharged state. In this study, we combine calculated cathode voltage information from both categories of cathode materials, covering 5577 and 2423 total unique structure pairs, respectively. The resulting voltage distributions with respect to the redox pairs and anion types for both classes of compounds emphasize design principles for high-voltage cathodes, which favor later Period 4 transition metals in their higher oxidation states and more electronegative anions like fluorine or polyanion groups. Generally, cathodes that are found in their charged, delithiated state are shown to exhibit voltages lower than those that are most stable in their lithiated state, in agreement with thermodynamic expectations. Deviations from this trend are found to originate from different anion distributions between redox pairs. In addition, a machine learning model for voltage prediction based on chemical formulas is trained and shows state-of-the-art performance when compared to two established composition-based ML models for material properties predictions, Roost and CrabNet.

Evaluation of Microwave Heating Uniformity for Ready-to-Eat Rice in Metalized Packaging Structure

Microwave energy utilization undergoes two stages via absorption and conversion inside ready-to-eat rice (RER) under microwave reheating. The reasonable utilization of microwave energy inside the processed material may enhance the uniformity of the temperature distribution. To analyze the uniformity changes inside RER, the effects of microwave reflection, refraction, and absorption by a metal aluminum film were studied through the thermodynamic properties. A simulation model was developed using the co-simulation method of COMSOL Multiphysics with MATLAB programming to analyze the mechanism of material properties and electromagnetic distribution on temperature distribution uniformity, as well as the formation mechanism of the temperature distribution uniformity of microwave-reheated RER. Based on models of the designed package boxes covering the metal film, the optimal structure was developed to include a metal aluminum film with a width of 5 mm and a thickness of 0.30 mm, which was sprayed on the edges and corners of a rectangular packaging box. The packaging boxes covering the metal films may reduce the average temperature of the upper and lower layers in RER by 8.03 °C and 7.42 °C, respectively, while the temperature distribution uniformity increased by 35.71% and 72.22%. The introduction of a metalized package significantly enhances the temperature uniformity inside RER under microwave reheating.

Local elasticity assessment of unidirectional fiber-reinforced polymer composites through impulse excitation and machine learning

This study presents a novel methodology that integrates the Impulse Excitation Technique (IET) and machine learning (ML) to predict local elastic properties within isolated regions of unidirectional polymeric composite plates. The proposed model incorporates fiber volume and plate thickness as input parameters and leverages the first resonance frequencies of the local region at different fiber orientations, thus accounting for the composite’s anisotropy. Regression results from the deep neural network (DNN) model demonstrate robust prediction performance across all output targets in both testing and training datasets, with R2 coefficients surpassing 0.9. The model exhibits particularly strong performance in predicting Young’s moduli. Additionally, each output objective shows sensitivity to a unique balance of input parameter weight factors for achieving optimal ML predictions. Moreover, a parabolic trend in the weight factors of fundamental frequencies at different orientations is observed as the rigidity of composites changes. Lastly, a comparative study between carbon-fiber and glass-fiber composites highlights the variations in fiber volume and elastic constants, emphasizing the effectiveness of the proposed model in accurately predicting material properties.

Seismic Behavior Analysis of a 14th Century Anatolian Seljuk Kumbet

The preservation of cultural heritage and the seismic resilience of historic buildings are crucial for maintaining social identity, particularly in earthquake-prone regions. This study focuses on the modeling of Sırçalı Kumbet, a Seljuk monument built in the 14th century in Kayseri province, located in the Central Anatolia region of Turkey, using survey drawings and analysis using the finite element method (FEM) to evaluate its seismic performance. The analysis indicates that linear elastic calculation methods can serve as an initial approach for evaluating such geometrically complex structures. The findings demonstrate that Sırçalı Kumbet exhibits substantial structural rigidity, reducing deformation and enhancing resistance to material fatigue during seismic events. Displacement and stress analyses under G+EQx and G+EQy loading conditions reveal that tensile and compressive stresses remain within acceptable limits, with localized exceedances occurring at specific points, such as cavity corners and wall bases. While these localized stresses are manageable, they highlight areas that require continuous monitoring and potential reinforcement to ensure long-term stability. Additionally, the study suggests that the integration of regular maintenance and targeted reinforcement measures can further improve the monument’s durability and minimize potential damage. This research underscores the essential role of the FEM in bridging the gap between cultural heritage conservation and seismic resilience. It provides a methodological framework for integrating architectural, restoration, and engineering expertise into comprehensive conservation strategies. Future studies should expand this approach to include various building types and material properties to enhance the development of preservation strategies.