Search Results (1,250)

This study experimentally investigates the use of stainless-steel woven wire mesh (SSWWM) as a patch material for repairing damaged glass fibre-reinforced (GFR) composite laminates. The effects of several factors on the three-point bending (3PB) behaviour of the parent laminate were examined, including the repair method (the plugging of open hole and the external patch repair), the mesh count of the SSWWM, and the number of SSWWM layers. According to the findings, all parameters considered in this study play a pivotal role in 3PB behaviour. Employing SSWWM as a patch material can recover 66.02–129.2% of the undamaged 3PB failure load, depending on the repair method, mesh count of the SSWWM, and number of SSWWM layers. Overall, decreasing the mesh count and increasing the number of SSWWM layers and applying an external patch repair method yield better results in terms of failure load and patch efficiency. This can be attributed to the increased wire diameter, improved bending rigidity, and better load distribution over a wider area. The SSWWM bridges the damaged zone, ensuring effective load transfer between the patch and parent laminate while preventing crack propagation. Utilising SSWWM as a patch material provides a quick, reliable solution for damage scenarios in engineering applications. Full article

Nowadays, there is an emphasis on reducing emissions due to industrial processes. In recent decades, filtration systems have become an integral part of the broadly understood heavy industry systems to reduce the emission of dust and other substances harmful to the environment and humans. Filters can also be found in heating, ventilation and air conditioning (HVAC) systems, in the transport industry, and their use in households is also increasing. The effective separation of micro- or nanometer contaminants is closely related to the development of new, sophisticated filter materials. Thanks to the use of modern tools for multiphase flow modeling, it becomes possible to model the flow inside the filter material. In this study, we propose a methodology to simulate the internal flow through porous structures with a fiber size of 5–30 µm. The geometry used to build the mathematical model is the actual geometry of the filter obtained using micro-Computed Tomography (CT) imaging method. The mathematical model has been validated against experimental data. In this article, we show the methodology to adapt a geometry scan for use in commercial Computational Fluid Dynamics (CFD) software (Ansys Fluent 2021 R1). Then we present the analysis of the influence of essential parameters of numerical model, namely the size of representative elementary volume (REV) of porous material, representation quality of porous matrix and numerical mesh density on the pressure drop in the filter. Based on the conducted research, the minimum size of the REV and the numerical mesh density were determined, allowing us to obtain a representative solution of the flow structure through the filtering material. The strong agreement between the model results and experimental data highlights the potential of using a multi-fluid mathematical model to understand filtration dynamics. Full article

This study develops a thermo-mechanical damage (TMD) model for predicting damage evolution in heterogeneous rock materials after heat treatment. The TMD model employs a Weibull distribution to characterize the spatial heterogeneity of the mechanical properties of rock materials and develops a framework that incorporates thermal effects into a nonlocal gradient damage model, thereby overcoming the mesh dependency issue inherent in homogeneous local damage models. The model is validated by numerical simulations of a notched cruciform specimen subjected to combined mechanical and thermal loading, confirming its capability in thermo-mechanical coupled scenarios. Sensitivity analysis shows increased material heterogeneity promotes localized, X-shaped shear-dominated failure patterns, while lower heterogeneity produces more diffuse, network-like damage distributions. Furthermore, the results demonstrate that thermal loading induces micro-damage that progressively spreads throughout the specimen, resulting in a significant reduction in both overall stiffness and critical strength; this effect becomes increasingly pronounced at higher heating temperatures. These findings demonstrate the model’s ability to predict the mechanical behavior of heterogeneous rock materials under thermal loading, offering valuable insights for safety assessments in high-temperature geotechnical engineering applications. Full article

To address the challenge of predicting lubrication states and reliability caused by the uncertainty of gear materials and structural parameters, a lubrication reliability analysis method considering the randomness of gear parameters is proposed. Firstly, a nonlinear dynamic model of a gear pair is established to derive the dynamic meshing force. The geometric and kinematic analyses are then performed to determine time-varying equivalent curvature radius and entrainment velocity. The minimum film thickness during meshing is further calculated. Considering gear parameters as random variables, a gear lubrication reliability model is formulated. Monte Carlo Simulation method is employed to accurately analyze the dynamic response, dynamic meshing force, equivalent curvature radius, entrainment velocity, probability distribution of minimum film thickness, and gear lubrication failure probability. Additionally, a specialized wear test device is designed to investigate the evolution of tooth surface roughness with wear and to forecast trends in gear lubrication failure probability as wear progresses. The results indicate that the uncertainty in gear parameters have minimal impact on the equivalent curvature radius and entrainment velocity, but significantly affect the dynamic meshing force. The gear speed and root mean square roughness are critical factors affecting lubrication reliability, and the early wear of the teeth enhances the lubrication reliability. The present work provides valuable insights for the design, maintenance, and optimization of high-performance gear systems in practical engineering applications. Full article

Neuroscience education must convey 3D structure with clarity and accuracy. Traditional 2D renderings are limited as they lose depth information and hinder spatial understanding. High-resolution resources now exist, yet many are difficult to use in the class. Therefore, we developed an educational brain video that moves from gross to microanatomy using MRI-based models and the published literature. The pipeline used Fiji for preprocessing, MeshLab for mesh cleanup, Rhino 6 for target fixes, Houdini FX for materials, lighting, and renders, and Cinema4D for final refinement of the video. We had our brain models validated by two neuroscientists for educational fidelity. We tested the video in a class with 96 undergraduates randomized to video and lecture or lecture only. Students completed the same pretest and posttest questions. Student feedback revealed that comprehension and motivation to learn increased significantly in the group that watched the video, suggesting its potential as a useful supplement to traditional lectures. A short, well-produced 3D video can supplement lectures and improve learning in this setting. We share software versions and key parameters to support reuse. Full article

Highly efficient shielding materials, transparent in the visible and IR ranges are becoming important in practice. This stimulates the development of cheap methods for creating transparent conductors with low sheet resistance and high optical transparency. This work presents a complex approach based on preliminary modeling of the shielding characteristics of two-layer sandwich structures based on irregular aluminum mesh (IAM) formed by the cracked template method. Experimentally measured spectral dependences of the transmission coefficient of single-layer IAM are used as a reference point for modeling. According to the simulation results, two types of sandwich structures were designed using IAM, with varying filling factors and a fixed PMMA layer thickness of 4 mm. The experimentally measured shielding characteristics of the sandwich structures in the range of 0.01–7 GHz are in good agreement with the calculated data. The obtained structures demonstrate a shielding efficiency of 55.96 dB and 65.55 dB at a frequency of 3.5 GHz (the average range of 5G communications). At the same time, their optical transparency at a wavelength of 550 nm are 84.07% and 75.78%, respectively. Our sandwich structures show electromagnetic shielding performance and uniform diffraction pattern. It gives them an advantage over structures based on regular meshes. The obtained results highlight the prospect of the proposed comprehensive approach for obtaining highly efficient, low-cost optically transparent shielding structures. Such materials are needed for modern wireless communication systems and metrology applications. Full article

Efficient and accurate forward modeling of electromagnetic fields is essential for advancing geophysical exploration in complex marine environments. However, realistic survey conditions characterized by low-frequency spectra, fine sedimentary strata, irregular bathymetry, and anisotropic materials pose significant challenges for conventional numerical methods. To address these issues, this work presents a parallel modeling framework that combines coordinate transformations with an adaptive high-order finite-element approach for 3D marine controlled-source electromagnetic (MCSEM) simulations. The algorithm exploits the form invariance of Maxwell’s equations to map the original boundary value problem over the physical domain to one defined over a computationally favorable domain filled with anisotropic media. The transformed model is then discretized and solved using a parallel high-order finite-element scheme enhanced with a goal-oriented adaptive mesh refinement strategy. We examine the performance of the proposed framework using both synthetic models and the realistic Marlim R3D benchmark dataset. The results demonstrate that the proposed approach can effectively reduce computational costs while maintaining high accuracy across a wide frequency range and varying water depths. These findings highlight the framework’s potential for large-scale, high-resolution CSEM exploration of offshore resources. Full article

A physics-informed neural network (PINN) framework is developed to model the large deformation and coupled electromechanical response of dielectric elastomer tubes for energy harvesting. The system integrates incompressible neo-Hookean elasticity with radial electric loading and compressible gas inflation, leading to nonlinear equilibrium equations with deformation-dependent boundary conditions. By embedding the governing equations and boundary conditions directly into its loss function, the PINN enables accurate, mesh-free solutions without requiring labeled data. It captures realistic pressure–volume interactions that are difficult to address analytically or through conventional numerical methods. The results show that internal volume increases by over 290% during inflation at higher reference pressures, with residual stretch after deflation reaching 9.6 times the undeformed volume. The axial force, initially tensile, becomes compressive at high voltages and pressures due to electromechanical loading and geometric constraints. Harvested energy increases strongly with pressure, while voltage contributes meaningfully only beyond a critical threshold. To ensure stable training across coupled stages, the network is optimized using the Optuna algorithm. Overall, the proposed framework offers a robust and flexible tool for predictive modeling and design of soft energy harvesters. Full article

The mutual twisting of steel wires is widely used in construction, engineering, and everyday applications, as it is relatively easy to perform and imparts new and useful properties to the wires. Since the process involves large deformations and high stress levels, understanding the mechanical behavior of twisted pairs is essential for both their manufacturing and in-service performance. This study provides a detailed analysis of the stresses and deformations that arise during the twisting of two galvanized steel wires with a diameter of 4 mm. Comprehensive information is presented on the development and validation of a suitable finite element model, with emphasis on geometry definition, the selection of appropriate initial and boundary conditions, and the meshing strategy. Special attention is devoted to the material properties, which are obtained and processed based on original tensile and torsion tests. Both the maximum and residual stresses are investigated. It is found that, for small twist pitches, the equivalent stresses during twisting can exceed the material’s yield strength by a factor of two or more, posing a risk of failure. The residual equivalent stresses show complex spatial distributions that vary with pitch, yet their average magnitudes remain within a narrow range, indicating a consistent residual stress level across different twisting configurations. Full article

Background/Objectives: Guided bone regeneration one of the most widely used techniques, relies on combining bone graft material with barrier membranes or meshes. The choice of the mesh material depends on the specific clinical situation. Among the available options, titanium membranes are recognized as one of the most effective in dental implantology. The latter can be categorized into two groups: commercial and individualized. Advancements in additive manufacturing make customized titanium meshes an attractive option for bone regeneration. Customized titanium meshes can be manufactured using three main methods: selective laser sintering (SLS), selective laser melting (SLM), and direct metal laser sintering (DMLS). This review aims to provide information about the differences between the production process and the clinical outcomes. Methods: This systematic review was conducted by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews (PRISMA-ScR). Relevant articles were sought out in the Web of Science, PubMed, and Scopus databases. Results: A total of ten articles were included and thoroughly reviewed. The type of bone graft used, the manufacturing technique, the amount of bone gain, the healing time, and the intraoperative and postoperative complications are discussed. Conclusions: All the relevant studies demonstrated good and predictable results using augmentation with individualized titanium meshes manufactured via SLS, SLM, or DMLS methods. Full article

The complexity of the processes occurring in both natural and artificial joints necessitates carrying out the analysis on a 3D model based on already existing mathematical models. All the presented numerical calculations define qualitative conclusions about the influence of certain parameters of endoprostheses on the values of stresses and strains arising in polyethylene parts of hip and knee endoprostheses. The obtained results make it possible to reveal “weak points” in the studied models and thus counteract the later effects resulting from premature wear of the endoprosthesis components. The study included a numerical analysis of the stress and strain distribution of polyethylene components of hip and knee endoprostheses working with the most commonly used material associations in this type of solution. The most common are metal alloys and ceramics. The analyses were carried out using ADINA and Autodesk Simulation Mechanical software. Geometric models were designed based on current solutions used by leading endoprosthesis manufacturers. The load models adopted are based on models commonly used in musculoskeletal biomechanics. Particular attention was paid to modeling the resistance due to friction at the hip endoprosthesis node. To build the hip endoprosthesis model, eight-node 3D solid elements were used. Due to the axisymmetric geometry of the model, the resulting discrete model consisted of 10,000 cubic elements described by 10,292 nodes. In the case of the knee endoprosthesis, a finite element mesh was adopted for the calculations, which was built with 3600 3D solid cubic elements and 4312 nodes. The accuracy of the adopted numerical model did not differ from the generally used solutions in this field. Full article

This article discusses contemporary strategies to deal with immersed boundary (IB) frameworks useful for analyzing flow–structure interaction in complex settings. It focuses on immense advancements in various fields: biology, oscillation of structures due to fluid flow, deformable materials, thermal processes, settling particles, multiphase systems, and sound propagation. The discussion also involves a review of techniques addressing moving boundary conditions at complex interfaces. Evaluating practical examples and theoretical challenges that have been addressed by these frameworks are another focus of the article. Important results highlight the integration of IB methods with adaptive mesh refinement and high-order accuracy techniques, which enormously improve computational efficiency and precision in modeling complex solid–fluid interactions. The article also describes the evolution of IB methodologies in tackling problems of energy harvesting, bio-inspiration propulsion, and thermal-fluid coupling, which extends IB methodologies broadly in many scientific and industrial areas. More importantly, by bringing together different insights and paradigms from across disciplines, the study highlights the emerging trends in IB methodologies towards solving some of the most intricate challenges within the technical and scientific domains. Full article

Introduction: Guided bone regeneration (GBR) is a key approach for managing alveolar ridge defects. Although titanium meshes are widely used for non-resorbable space maintenance, their limitations have prompted interest in alternative materials. Polyetheretherketone (PEEK), a high-performance thermoplastic, has emerged as a potential barrier due to its mechanical strength, radiolucency, and compatibility with digital workflows. Objective: To map the current evidence on the use of PEEK barriers in GBR, focusing on biological performance, mechanical properties, and clinical outcomes in animal and human studies. Methods: A scoping review was conducted following PRISMA-ScR guidelines. Eligible studies included in vivo animal models or clinical trials involving PEEK barriers for alveolar bone regeneration. Data on study design, defect type, barrier characteristics, surgical protocol, outcomes, and complications were extracted. Results: Five studies met the inclusion criteria: two animal models and three clinical trials. All reported successful space maintenance and bone gain with PEEK barriers, with outcomes comparable to titanium meshes. Customization through CAD/CAM or 3D printing was common. Complications such as soft tissue dehiscence and exposure occurred but generally did not affect regeneration. Evidence was limited by small sample sizes, short follow-up, and single-center designs. Conclusions: PEEK barriers show promise as customizable alternatives to traditional GBR membranes. However, current evidence is limited and geographically concentrated. Future multicenter studies with long-term follow-up and standardized outcome measures are needed to validate the clinical potential of PEEK in bone regeneration. Full article

Sustainability in the construction and building sector with the use of greener and more eco-friendly building materials can minimize carbon footprint, which is one of the prime goals of the twenty-first century. The use of natural fibers in ancient and traditional buildings and structures is not new, but in the last fifty years, only man-made fibers have predominantly occupied the market for structural retrofitting or upgrading. This research investigated the potential of utilizing natural fibers, particularly jute fiber products, to enhance masonry’s thermal and structural characteristics. The study meticulously investigated the utilization of materials such as jute net (with a mesh size of 2.5 cm × 1.25 cm), jute fiber diatons, and jute fiber composite mortar (with 1% jute fiber with respect to the dry mortar mass) in the context of masonry upgrading. The research evaluated the structural and thermal performance of these upgraded walls. Notably, the implementation of natural fiber textile-reinforced mortar (NFTRM) resulted in an astounding increase of over 500% in the load-bearing capacity of the walls, while simultaneously enhancing insulation by more than 36%. Furthermore, the study involved a meticulous analysis of crack patterns during in-plane cyclic testing utilizing the advanced Digital Image Correlation (DIC) tool. The upgraded/retrofitted wall exhibited a maximum crack width of approximately 7.84 mm, primarily along the diagonal region. Full article

This study assesses how different anode materials influence neutron production rates (NPRs) in multi-state fusion (MSF) reactors, with a particular focus on the effects of deuterium (D) pre-loading on the anode surface. Three types of mesh anodes were assessed: stainless steel (SS), zirconium (Zr), and D pre-loaded zirconium (ZrD). MSF operates using two electrodes to confine ions to various fusion reactions, including D-D and D-T. The reactor features a negatively biased central cathode and a grounded anode within a vacuum vessel. Neutrons and protons are produced through the application of high voltage (tens of kV) and current (tens of mA) on the system to spark the plasma and start the fusion. Assessments at voltages up to 50 kV and currents up to 30 mA showed that Zr mesh anodes produced higher NPRs than SS ones, reaching 1.912 at 30 kV. This increased performance is attributed to surface fusion processes occurring in the anode. These processes were further modified by the deuterium pre-loading in the ZrD anode, as compared to SS and Zr with 1.832 at 30 kV. The findings suggest that material properties and deuterium pre-loading play significant roles in optimizing the efficiency of MSF reactors and the NPR. Future research may explore the long-term stability and durability of these anode materials under continuous operation conditions to fully harness their potential in fusion energy applications. Full article