Mesh Approach Research Articles

Infinite-time optimal feedback control of a 3-phase asynchronous motor exploiting a nonlinear finite element model

This paper presents modelling of a squirrel-cage induction motor and an optimal control method based on suboptimal control for nonlinear systems to minimise consumed energy and power losses in an induction motor drive. A coupled motor model with optimal control as a closed-loop integrated system is proposed. For modelling of the squirrel-cage asynchronous machine, a field-circuit-mechanical finite-element (FE) model is employed, in which mechanical motion is realised by a moving-mesh method and fixed mesh approach. For the control problem purpose, a surrogate induction motor model, described in a stationary rotor reference d–q frame, is applied. The optimal control is realised by a nonlinear feedback compensator method based on the state-dependent Riccati equation (SDRE) with an infinite time horizon with the surrogate model state-dependent parametrisation (SDP). To perform the control strategy, a SDRE technique with Moore–Penrose pseudoinverse is adopted. To improve the accuracy of the optimisation procedure, a finite element model was used to calculate the motor performance.

Comparison of early and late term results of onlay and sublay mesh approaches in open incisional hernia surgery

Aims: Despite the increase in minimally invasive techniques, open techniques continue to be frequently used in incisional hernia repairs. In open incisional hernia surgeries, onlay and sublay techniques are the most frequently preferred depending on the area where the mesh is placed. In this study, we aimed to compare these two techniques by analyzing perioperative findings. Methods: Data from elective open incisional hernia surgeries (onlay and sublay) performed by the same surgical team in the general surgery clinic between 01.01.2023 and 31.12.2023 were retrospectively reviewed. Emergency surgeries, laparoscopic or combined surgeries, patients who did not undergo mesh repair, patients who received preoperative botulinum toxin due to “loss of domain”, patients with missing data, and patients who did not continue their follow-up were excluded from the study. Results: The data of a total of 74 patients who met the inclusion criteria were analyzed in the study. Onlay procedure was performed in 53 (71%) patients and sublay procedure was performed in 21 (19%) patients with a retromuscular approach. No intraoperative complications were detected in any of the patients. There were statistically significant differences between the groups in terms of female gender (p: 0.007), duration of surgery (p<0.001) and duration of hospital stay (p<0.001). There were no statistically significant differences between the groups in terms of complications (p:0.42), unexpected re-admission (p:0.779) and six-month recurrence (p: 0.779). Conclusion: Onlay or sublay techniques can be safely applied in open incisional hernia surgery because they have acceptable complication and recurrence rates. Surgical experience and patient factors are the main determinants of which technique to apply.

Enhancing data representation in forging processes: Investigating discretization and R-adaptivity strategies with Proper Orthogonal Decomposition reduction

Effective data reduction techniques are crucial for enhancing computational efficiency in complex industrial processes such as forging. In this study, we investigate various discretization and mesh adaptivity strategies using Proper Orthogonal Decomposition (POD) to optimize data reduction fidelity in forging simulations. We focus particularly on r-adaptivity techniques, which ensure a consistent number of elements throughout the field representation, filling a gap in existing research that predominantly concentrates on h-adaptivity. Our investigation compares isotropic mesh approaches with anisotropic mesh adaptations, including gradient-based, isolines-based, and spring-energy-based methods. Through numerical simulations and analysis, we demonstrate that these anisotropic techniques provide superior fidelity in representing deformation fields compared to isotropic meshes. These improvements are achieved while maintaining a similar level of model reduction efficiency. This enhancement in representation leads to improved data reduction quality, forming the foundation for data-driven models. This research contributes to advancing the understanding of mesh adaptivity approaches and their potential applications in data-driven modeling across various industrial domains.

A neural network approach for unstructured mesh quality evaluation

PurposeThe quality of the unstructured mesh has a considerable impact on the stability and accuracy of aerodynamic simulation in computational fluid dynamics (CFD). Typically, engineers spend a significant portion of their time on mesh quality evaluation to ensure a valid, high-quality mesh. The extensive manual interaction and a priori knowledge required to undertake an accurate and timely evaluation process have become a bottleneck in the idealized efficient CFD workflow. This paper aims to introduce a neural network-based quality evaluation approach for unstructured meshes to enable higher efficiency and the level of automation.Design/methodology/approachThe paper investigates the capability of deep neural networks for the quality evaluation of unstructured meshes. For training the network, we build a training dataset for mesh quality learning algorithms. The dataset contains a rich variety of unstructured aircraft meshes with different mesh sizes, densities, cell distribution, growth ratios and cell numbers to ensure its diversity and availability. We also design a neural network, AircraftNet, to learn the effect of mesh quality on the convergent properties of the numerical solutions. The proposed network directly manipulates raw point data in mesh source files rather than passing it to an intermediate data representation. During training, AircraftNet extracts non-linear quality features from high-dimensional data spaces and then automatically predicts the overall quality of the input unstructured mesh.FindingsThe paper provides a series of experimental results on GPUs. It shows that AircraftNet is able to effectively analyze the quality-related features like mesh density and distribution from the extracted features and achieve high prediction accuracy on the proposed dataset with even a small number of training runs.Research limitations/implicationsBecause of the limited training dataset, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further.Originality/valueThe paper publishes a benchmarking dataset for mesh quality learning algorithms and designs a novel neural network approach for unstructured mesh quality evaluation.

Enhanced modeling of vehicle-induced turbulence and pollutant dispersion in urban street canyon: Large-eddy simulation via dynamic overset mesh approach

This study presented a novel application of large-eddy simulation (LES) with a dynamic overset mesh approach to simulate vehicle-induced turbulence in a two-dimensional street canyon. The simulation incorporated moving vehicle entities to emulate two-way traffic, with each vehicle equipped with a pollutant source to simulate pollutant dispersion. Comprehensive long-term statistical analyses were conducted to compare the simulated turbulence with those produced by the conventional approach (where vehicle-induced momentum was not considered) and the quasi-steady method (where vehicle motion was simplified as momentum sources). The results revealed that the presence of moving vehicle entities significantly distorted the primary circulation within the canyon, altering the transport pathways of both lateral momentum and air pollutants. The motion of vehicle entities also induced a substantial amount of turbulence, resulting in different pollutant removal mechanisms at the top of the canyon. The ensemble-average analysis revealed a downwash followed by an upwash within a cycle of vehicle movement, which largely contributed to momentum and pollutant transport. These findings underscored the need for considering the moving entities in LES approaches to enhance vehicle-induced turbulence modeling. Other factors influencing the simulation were discussed, aiming to guide more accurate and reliable turbulence modeling in urban environments.

Stress‐Aligned Hexahedral Lattice Structures

AbstractMaintaining the maximum stiffness of components with as little material as possible is an overarching objective in computational design and engineering. It is well‐established that in stiffness‐optimal designs, material is aligned with orthogonal principal stress directions. In the limit of material volume, this alignment forms micro‐structures resembling quads or hexahedra. Achieving a globally consistent layout of such orthogonal micro‐structures presents a significant challenge, particularly in three‐dimensional settings. In this paper, we propose a novel geometric algorithm for compiling stress‐aligned hexahedral lattice structures. Our method involves deforming an input mesh under load to align the resulting stress field along an orthogonal basis. The deformed object is filled with a hexahedral grid, and the deformation is reverted to recover the original shape. The resulting stress‐aligned mesh is used as basis for a final hollowing procedure, generating a volume‐reduced stiff infill composed of hexahedral micro‐structures. We perform quantitative comparisons with structural optimization and hexahedral meshing approaches and demonstrate the superior mechanical performance of our designs with finite element simulation experiments.

Numerical evaluation of wear parameters using meta-models

AbstractWear parameters identified by linear friction tester (LFT) experiments overestimate the wear mass loss when applied on a laboratory abrasion & skid tester 100 (LAT100) simulation. On the other hand, the identification of wear parameters directly from the LAT100 experiment can be challenging since variables such as the contact area and the slip velocity are not measured experimentally and need to be assumed. To improve the identification process, numerical calibration is used as a more suitable approach. This approach relies on meta-models as a target function for minimization. The meta-models are generated using a sample of wear parameters applied to an LAT100 finite element modeling (FEM) to calculate the corresponding wear mass.. In this model, a transport velocity is defined for the rolling simulation, and an arbitrary lagrangian–eulerian (ALE) adaptive meshing approach is adopted for the wear modeling. For the wear model, a combination of archard’s wear model and schallamach’s abrasion law is used. This model contains a pair of wear parameters to be identified. The ALE adaptive meshing technique moves the nodes independently of the material. Since the mesh topology remains the same, failure of the simulation occurs if the wear volume loss exceeds that of the element. Meta-models are created to extend wear modeling beyond this failure. Once the meta-models are created, they are used as a target function for the minimization algorithm. The minimization algorithm aims to find the optimal wear parameters by minimizing the difference between experimentally observed and numerically produced wear mass loss. The minimization algorithm inputs a set of wear parameters into the meta-models which in turn yield a prediction of the wear mass loss. The process is carried out until an optimum parameter set is identified. Such an approach has a lower accuracy if the parameters are identified directly from the experiment using assumptions regarding the contact shear stress and the sliding velocity. Nonetheless, the main advantage of parameters identified using the meta-model approach is the usability of these parameters in an LAT100 model.

Estimation of added effects and their frequency dependence in various fluid–structure interaction problems

This paper focuses on a fluid–structure interaction topic—the determination of added effects caused by fluid forces acting on a body, considering the standard linear equation of motion. We present various problems that assume small-displacement oscillations of single and multiple bodies in inviscid irrotational (potential) flow or viscous incompressible flow in both closed domain and external flow. For inviscid flow, effects of geometric parameters on the added effects were studied. The presented results extend results known from the literature. For viscous flow, frequency dependence of the added effects was studied for a wide range of frequency. The added effects were computed from data from numerical simulations of fluid flow, where the body oscillations were modeled using the dynamic mesh approach. Effects of the phase shift caused by the dynamic mesh were addressed. The added mass was compared with the corresponding value determined for inviscid flow where applicable. The results show strong dependence of the added effects on many parameters, making their proper computation challenging even for simplified cases.

Numerical investigation on steady turning motion of a generic submarine near the free surface

This study investigated the steady turning motion of a generic submarine near the free surface using computational fluid dynamics (CFD) methods. The Joubert BB2 submarine and Marine 7371R propeller models were employed as the subjects of this research. The analysis utilized the Reynolds-averaged Navier-Stokes (RANS) equations with the SST k-ω turbulence model to capture turbulent flows, and the volume of fluid (VOF) method to capture the free surface dynamics. A mesh convergence study was conducted with three different mesh resolutions to ensure the accuracy of the simulations. An overset mesh method was used to control the submarine and its four control surfaces, while a sliding mesh approach simulated the propeller rotation. The self-propulsion point of the submarine was determined at a fixed speed using a PI controller. Subsequently, rudder maneuvers were executed to replicate a steady 20-degree turning motion. The study examined the effects of submergence depth and speed on the flow field. Results indicated an approximate 15% variation in turning parameters between the maximum and minimum submergence depths at the same speed, with force and torque differences around 30%. Additionally, the study explored the impact of the free surface on hydrodynamic forces, pressure distribution, free surface wave patterns, and vortex structures during turning maneuvers.

Implicit unified gas-kinetic scheme for steady state solution of hypersonic thermodynamic non-equilibrium flows

The unified gas-kinetic scheme (UGKS), designed to solve Boltzmann equation and its model equations, aims to accurately resolve multi-scale flow problems within a single computation framework. In this study, an implicit UGKS is proposed for the steady state solution of diatomic gas flows based on a multiple-temperature Boltzmann model equation with non-equilibrium among translational, rotational and vibrational modes (Zhang et al., 2023), utilizing a novel hybrid Cartesian-unstructured discrete velocity space (DVS) mesh approach. The multiple-temperature macroscopic equations corresponding to the Boltzmann model equation are simultaneously solved implicitly to address the stiffness and nonlinearity of the collision operator encountered when solving the Boltzmann model equation in isolation. Both macroscopic equations and Boltzmann model equation are solved by using the point relaxation symmetric Gauss–Seidel method to achieve a fast convergence rate. The efficiency of the implicit UGKS can be improved by about two orders of magnitude compared to the explicit one. Moreover, the hybrid Cartesian-unstructured DVS achieves a noteworthy reduction in both CPU-hours and memory consumption, requiring only 15%∼23% of the advanced unstructured DVS. It effectively alleviates the dimensional crisis of UGKS in solving three-dimensional hypersonic flows, and can be extended to other DVS-based methods. As a result, UGKS extends its applicable regime to simulations of hypersonic thermodynamic non-equilibrium flows with Mach numbers up to 30, achieving three-dimensional flow simulations of complex geometrical configurations with relatively low computational resources. A series of test cases, including normal shock structures, two-dimensional hypersonic flows around cylinder, blunt wedge and flat plate, and three-dimensional hypersonic flows around a sphere and an X38-like configuration vehicle, are conducted to validate the implicit UGKS with hybrid Cartesian-unstructured DVS. Overall, the proposed method shows advantages of unified multi-scale methods in terms of computational efficiency and capturing multi-scale solution of hypersonic thermodynamic non-equilibrium flows.

Role of periodic oscillating flow modulators on mixed convection in a long horizontal channel

Present study explores mixed convection characteristics in a long horizontal channel subjected to multiple periodically distributed flow modulators. The flow modulators are represented by oscillating blades placed along a centerline of the channel whose lower and upper walls are kept at constant high and low temperatures respectively. In replicating the blade oscillation, moving mesh approach has been adopted within Arbitrary Lagrangian–Eulerian (ALE) framework for a representative periodical unit. The corresponding non-dimensional governing mass, momentum and energy conservation equations have been solved through Galerkin finite element solver for a wide variations of modulator's dynamic condition (oscillating frequency and maximum angular displacement) for different fluids represented by Prandtl number. Heat transfer performance of the system has been demonstrated in terms of spatially-averaged transient as well as time-averaged Nusselt number while qualitative analysis of fluid flow and thermal field has been presented as streamline and isotherm plots. Present study indicates that the time averaged Nusselt number undergoes significant variation with blade oscillating frequency and maximum angular displacement depending on both the Prandtl number and Reynolds Number. Power spectrum analysis obtained through Fast Fourier Transformation (FFT) of the imposed blade frequency and induced thermal frequency reveals different correlation depending on the blade frequency. Blade friction power requirement has been found to increase at higher blade frequency as well as maximum angular displacement. However, contrary to power consumption, increase in frequency does not result in a significant rise in heat transfer. Consequently, specific heat transfer decreases at higher blade oscillating frequency and maximum angular displacement.

Impacts of finned rotating cylinder on hydrothermal flow of hybrid nanofluids in a vented cavity based on dynamic mesh approach

This study aims to explore and enhance the understanding of how finned rotating cylinders impact mixed convection of the hydrothermal flow and heat transfer of hybrid nanofluids in a vented cavity. The significance of this study contributes to the advancement of increasingly efficient and productive thermal control mechanisms in diverse industrial sectors employing rotating cylinders. Simulations employ a dynamic mesh approach to model the flow domain and boundary motion of the rotating bladed cylinder based on the finite volume technique. The presented results underwent a rigorous comparison with existing related works in the open literature. The chosen working fluid is a Newtonian hybrid nanofluid composed of SiO2-Al2O3 suspended in water. Various configurations of cylinder locations and sizes are examined, alongside a broad spectrum of associated variables with certain ranges. These parameters with defined ranges are; Reynolds numbers (2 × 102 ≤ Re ≤ 1 × 103), cylinder radius (0.1 ≤ R≤0.3), cylinder locations (0.25 ≤ δ ≤ 0.75), spinning speeds (− 3 ≤ Ω ≤ 3), and nanoparticle concentrations (0 ≤ φ1 ≤ 0.03 and 0 ≤ φ2 ≤ 0.03). The results indicate significant impacts of Reynolds numbers (Re), Grashof numbers (Gr), cylinder radius (R), location (δ), spinning speed (Ω), and the number of blades on the hydrothermal characteristics. The major finding states that the cylinder radius of 0.3 for Case 5 with five fins provides the greatest enhancement of mixed flow and relatively maximum heat transfer rate. Furthermore, increasing concentrations of nanoparticles (φ) of hybrid nanofluids further improves the thermal performance.

A lightweight interactive approach for unstructured surface mesh generation

PurposeThe paper aims to propose a generation approach for unstructured surface mesh to speed up mesh generation.Design/methodology/approachThe paper proposes a lightweight interactive generation approach for unstructured surface mesh and presents several key technologies to support this approach.FindingsThe experimental results show that the proposed approach is feasible for unstructured meshes and it can accelerate the mesh generation process.Research limitations/implicationsMore geometric defects should be covered, and more convenient and efficient interactive means need to be provided.Practical implicationsThe proposed approach and key technologies are implemented in NNW-GridStar.UG, which is the unstructured version of the mesh generation software of National Numerical Windtunnel (NNW).Originality/valueThis paper proposes a lightweight interactive approach for unstructured surface mesh generation, which can speed up mesh generation.

Supervertex Sampling Network: A Geodesic Differential SLIC Approach for 3D Mesh.

The analysis of 3D meshes with deep learning has become prevalent in computer graphics. As an essential structure, hierarchical representation is critical for mesh pooling in multiscale analysis. Existing clustering-based mesh hierarchy construction methods involve nonlinear discretization optimization operations, making them nondifferential and challenging to embed in other trainable networks for learning. Inspired by deep superpixel learning methods in image processing, we extend them from 2D images to 3D meshes by proposing a novel differentiable chart-based segmentation method named geodesic differential supervertex (GDSV). The key to the GDSV method is to ensure that the geodesic position updates are differentiable while satisfying the constraint that the renewed supervertices lie on the manifold surface. To this end, in addition to using the differential SLIC clustering algorithm to update the nonpositional features of the supervertices, a reparameterization trick, the Gumbel-Softmax trick, is employed to renew the geodesic positions of the supervertices. Therefore, the geodesic position update problem is converted into a linear matrix multiplication issue. The GDSV method can be an independent module for chart-based segmentation tasks. Meanwhile, it can be combined with the front-end feature learning network and the back-end task-specific network as a plug-in-plug-out module for training; and be applied to tasks such as shape classification, part segmentation, and 3D scene understanding. Experimental results show the excellent performance of our proposed algorithm on a range of datasets.

Effect of buoyancy force on buoyancy waterwheel efficiency using numerical flow simulation

In this work, the performance of a buoyant waterwheel to produce hydrokinetic power is investigated through analytical theory and computational fluid dynamics simulation. The impact of the buoyancy wheel is investigated by establishing the performance parameters through the use of a moving mesh approach and a realizable k-ε turbulence model. Transient simulation is required to comprehend the flow of physical processes. Using moving mesh as a transient methodology of the buoyancy waterwheel, numerical flow simulations and theoretical analytical methods are used in this study to assess the effect of buoyant force generated on the performance of the buoyancy wheel. The buoyancy waterwheel that will be put to the test has eight straight blades and a diameter of one meter. The pinwheel force and torque created in the numerical flow simulation (CFD) are 414.96 N and 207.48 Nm, respectively, whereas in the theoretical calculation they are 449.06 N and 224.53 Nm, according to the research findings. It is possible to compute the buoyancy wheel's power output and efficiency mathematically, yielding values of 1619.35 W and 68.07%. The buoyancy wheel's power output and efficiency, as determined by numerical flow simulation, are 1495.95 W and 62.88%, respectively. Based on theoretical and CFD study results, the buoyancy wheel generates a standard deviation of 7.62%. Thus, for the buoyancy wheel, a temporary method that makes advantage of the moving mesh characteristic is advised. This method can also be applied as a future alternative energy source for the Piko hydro turbine

Conforming mesh modeling of multi-physics effect on residual stress in multi-layer powder bed fusion process

The current research aims to predict the residual stress accumulation and evolution in the powder bed fusion processed multi-layer thin wall structures through a conforming mesh modeling approach. It involves the discrete element method (DEM) interfaced with the volume of fluid (VOF) method using computational fluid dynamics (CFD) coupled with the finite element method (FEM). The conforming mesh approach developed in the research predicts multi-physics, its induced porosity, and the cumulative effect on the residual stress in the powder bed fusion processed Ti-6Al-4V thin wall structures. The results of the residual stress in the multi-layered component from this method were further quantitatively compared with the non-conforming finite element method. The results show the conforming mesh approach was not only effective in capturing the layer geometry, and defects induced during the printing, but also predicted the residual stress in the region of the defect more accurately than the non-conforming mesh methods.

Effects of mechanical vibration on melting characteristics of latent thermal energy storage units using the dynamic mesh method

Phase change materials (PCM) based thermal energy storage technology is an efficient method to overcome the intermittency and instability of energy supply. The heat transfer performance of PCM can be enhanced by the mechanical vibration technique, but the potential mechanisms remain to be revealed. In this study, a dynamic mesh approach was proposed to numerically investigate the effect of mechanical vibrations on the heat transfer performance of PCM. The results indicate that the increase of the vibration frequency leads to the increase of the melting rate, with the vibration frequency increasing from 0 to 3π and 5π, the complete melting time of PCM under vertical vibration can be decreased by 2.21 % and 3.74 %, and complete melting time under horizontal vibration can be decreased by 34.35 %, and 44.39 %, which means that the horizontal vibration exhibits a superior heat transfer enhancement effect. However, it was also found that the energy utilization effect was decreased with the increase of vibration frequency through energy assessment. In addition, the vibration has both promoting and inhibiting effects on the phase transition process, which is related to the melting state and vibration phase. This work provides a novel approach to vibrational simulations and an important guide for practical applications of vibrational heat transfer enhancement.

Outcomes of Laparoscopic Suture Rectopexy Versus Laparoscopic Mesh Rectopexy: A Systematic Review and Meta-Analysis.

The contemporary literature provides conflicting evidence regarding the precedence of laparoscopic mesh rectopexy over laparoscopic suture rectopexy for full-thickness rectal prolapse. This study aimed to compare the clinical outcomes of mesh and suture rectopexy to improve the surgical management of complete rectal prolapse.The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to extract studies based on mesh versus suture rectopexy and published from 2001 to 2023. The articles of interest were obtained from PubMed Central, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Journal Storage (JSTOR), Web of Science, Embase,Scopus, and the Cochrane Library. The primary outcomes included rectal prolapse recurrence, constipation improvement, and operative time. The secondary endpoints included the Cleveland Clinic Constipation Score, Cleveland Clinic Incontinence Score, intraoperative bleeding, hospital stay duration, mortality, overall postoperative complications, and surgical site infection.A statistically significant low recurrence of rectal prolapse (odds ratio: 0.41, 95% confidence interval (CI) 0.21-0.80; p=0.009) and longer mean operative duration (mean difference: 27.05, 95% CI 18.86-35.24; p<0.00001) were observed in patients with mesh rectopexy versus suture rectopexy. Both study groups, however, had no significant differences in constipation improvement and all secondary endpoints (all p>0.05).The laparoscopic mesh rectopexy was associated with a low postoperative rectal prolapse recurrence and a longer operative duration compared to laparoscopic suture rectopexy. Prospective randomized controlled trials should further evaluate mesh and suture rectopexy approaches for postoperative outcomes to inform the surgical management of complete rectal prolapse.

LAPARASCOPIC VERSUS OPEN MESH REPAIR FOR RECURRENT INGUINAL HERNIA: A SYSTEMATIC REVIEW

Background: Inguinal hernia is one of the most common conditions seen in clinic, and is often treated through the general surgery department. Laparoscopic repair and open repair with mesh are the typical treatments for inguinal hernia, and both regimens have proved beneficial in treating inguinal hernia. However, recurrence, with a rate as high as 33, poses a significant problem to the effective treatment of inguinal hernia. The aim: This study aims to show about laparascopic versus open mesh repair for recurrent inguinal hernia. Methods: By comparing itself to the standards set by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020, this study was able to show that it met all of the requirements. So, the experts were able to make sure that the study was as up-to-date as it was possible to be. For this search approach, publications that came out between 2013 and 2023 were taken into account. Several different online reference sources, like Pubmed and SagePub, were used to do this. It was decided not to take into account review pieces, works that had already been published, or works that were only half done. Result: In the PubMed database, the results of our search brought up 10 articles, whereas the results of our search on SagePub brought up 60 articles. The results of the search conducted for the last year of 2013 yielded a total 2 articles for PubMed and 14 articles for SagePub. The result from title screening, a total 1 articles for PubMed and 10 articles for SagePub. In the end, we compiled a total of 7 papers. We included five research that met the criteria. Conclusion: The laparoscopic approach is superior to the open mesh approach for the repair of recurrent inguinal hernia in some aspects, including the incision infection rate and length of hospital stay. However, more high-quality studies on the effects of laparoscopic and open mesh repair for the treatment of recurrent inguinal hernia are warranted.

Localized heat treatment and XFEM-based investigation of damage mechanisms in reinforced notched plates under uniaxial tensile stress

This study delves into mechanical engineering by investigating damage mechanisms and reinforcement strategies in notched structures. Our research centers on enhancing structural integrity through a localized heat treatment technique applied at the notch before uniaxial tensile stress testing. Central to our approach is Functionally Graded Material (FGM), defined by volume fractions that specific exponents modulate. The innovation lies in treating the interface between the base metal and the heat-affected zone (HAZ). We introduce a novel meshing-based grading technique that facilitates elastoplastic behavior and allows for the gradation of damage properties. This technique is particularly noteworthy as it obviates the need for complex subroutines or FORTRAN compilation. Our methodology employs a mesh model with independent elements, each characterized by a volume fraction gradient to accurately represent the graded material’s behavior. The behavioral model is anchored in the Von Mises equivalent stress flow theory, and tensile tests inform the material properties of steel and the HAZ. The results of our investigation are presented through force-displacement curves, which critically evaluate our reinforcement technique. Moreover, using the eXtended Finite Element Method (XFEM) in our meshing approach has proven particularly effective in delineating structural behavior post-fissure initiation, showcasing its superiority in capturing the nuances of crack propagation and structural separation.