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As a method of lightweight design, multi-material design aims to make targeted use of materials in order to reduce CO2 emissions. In this context, it can be described as one of the product development methods used to meet the challenges of climate change. However, since the design of structures in multi-material design is complex, topology optimization can be used to support the product developer. In this article, a multi-material topology optimization method is developed that combines the Velocity Field Level Set method with the Reconciled Level Set method. Furthermore, the current design is explicitly resolved in each iteration by means of multi-material remeshing. The edge collapse phase in the remeshing process is achieved by applying the producer consumer pattern. The developed method is then validated using known examples from the state of research, and the influence of the parameters of the method on the result is analyzed by means of studies. [ABSTRACT FROM AUTHOR]

Large strain analysis is a challenging task, especially in fictitious or immersed boundary domain methods, since badly broken elements/cells can lead to an ill-conditioned global tangent stiffness matrix, resulting in convergence problems of the incremental/iterative solution approach. In this work, the finite cell method is employed as a fictitious domain approach, in conjunction with an eigenvalue stabilization technique, to ensure the stability of the solution procedure. Additionally, a remeshing strategy is applied to accommodate highly deformed configurations of the geometry. Radial basis functions and inverse distance weighting interpolation schemes are utilized to map the displacement gradient and internal variables between the old and new meshes during the remeshing process. For the first time, we demonstrate the effectiveness of the remeshing approach using various numerical examples in the context of finite strain elastoplasticity. [ABSTRACT FROM AUTHOR]

The Smoothed Particle Finite Element Method (SPFEM) has gained popularity as an effective numerical method for modelling geotechnical problems involving large deformations. To promote the research and application of SPFEM in geotechnical engineering, we present ESPFEM2D, an open-source two-dimensional SPFEM solver developed using MATLAB. ESPFEM2D discretizes the problem domain into computable particle clouds and generates the finite element mesh using Delaunay triangulation and the α -shape technique to resolve mesh distortion issues. Additionally, it incorporates a nodal integration technique based on strain smoothing, effectively eliminating defects associated with the state variable mapping after remeshing. Furthermore, the solver adopts a simple yet robust approach to prevent the rank-deficiency problem due to under-integration by using only nodes as integration points. The Drucker-Prager model is adopted to describe the soil's constitutive behavior as a demonstration. Implemented in MATLAB, this open-source solver ensures easy accessibility and readability for researchers interested in utilizing SPFEM. ESPFEM2D can be easily extended and effectively coupled with other existing codes, enabling its application to simulate a wide range of large geomechanical deformation problems. Through rigorous validation using four numerical examples, namely the oscillation of an elastic cantilever beam, non-cohesive soil collapse, cohesive soil collapse, and slope stability analysis, the accuracy, effectiveness and stability of this open-source solver have been thoroughly confirmed. [ABSTRACT FROM AUTHOR]

This paper presents a Computational Fluid Dynamics (CFD) simulation of the quenching process based on ISO 9950, focusing on the heat flux and heat transfer coefficient integrated over a metal specimen. The numerical method, which employs the two-fluid VOF method and frozen turbulence approach (Cukrov et al., Appl. Sci. 2023, 13, 9144), is used for the transient simulation. Since quenching processes involve complex boiling phenomena shifting from film boiling to nucleate boiling, a standard method based on VOF cannot be applied. The comparison of the simulation results with the ones obtained using correlation, and the data obtained using the Inverse Heat Transfer Analysis (IHTA) method have revealed that the proposed method can accurately predict the heat flux and heat transfer coefficient in the film boiling regime of the immersion quenching process. Note that the previous paper (Cukrov et al., Energies. 2023, 16, 7926.) presented the immersion process modeling and the temperature distribution, while the current paper examines the heat transfer characteristics of the immersion quenching process.

Surface Reconstruction from raw Pointclouds generates polygonal meshes characterised by typical local issues that need to be addressed by a global reorganisation of mesh connectivity during the Remeshing process. While in the applications for which remeshing algorithms have historically been developed, the problem can be addressed without affecting the mesh polycount, for the authoring of 3D assets intended for Real-Time Rendering applications, maintaining a low polycount is mandatory. However, there is a trade-off between the number of polygons and accuracy. Hence, in cases where accuracy is a primary concern, such as with Digital Cultural Heritage Objects, the topology of the mesh that ensures this reduction becomes crucial since, to an even polycount, the dimensional discrepancy between the original and different simplified meshes can vary significantly.Therefore, it is vital to evaluate the characteristic quality obtainable from different remeshing algorithms with simplification, but despite the importance of the matter, there is a lack of metrics to perform such comparative benchmarks. This study aims to address this gap by defining and testing a Shape Complexity Index on real-world case studies, which is applicable uniformly and consistently to geometric shapes of generic complexity. Such index allows for pre-determine a target polycount and subsequently normalising signed distance computations among different test simplified meshes, posing the basis for both quantitative and qualitative analysis of accuracy achievable by any automatic remeshing tool. Additionally, the proposed workflow is employable as an instrument for planning, monitoring, and reporting a digitisation campaign of objects belonging to the Cultural Heritage.DOI: https://doi.org/10.20365/disegnarecon.32.2024.10

In this work, a three-dimensional fluid-structural and vibro-acoustics coupled model of a gear pump is presented. Gear pumps represent the majority of the positive displacement machines used for flow generation in fluid power systems. Typically, the dynamics of gear pumps are dependent on the characteristics of the fluid dynamics inside the pump, which translates into vibrations to the housing. These vibrations then propagate to the surrounding medium and emit sound. The purpose of this study is to propose a three-dimensional fully integrated computational model to simulate the complete gear pump behaviour from the fluid dynamics to the structural vibrations, up to the vibroacoustic response. In this hybrid configuration, a transient CFD (Computational Fluid Dynamics) model is first developed to simulate the 3D flow field with a deforming and re-meshing approach to take into account the variation of the volume between the gears. Second, the internal pressure field calculated at each time step is then used as a loading into a structural FEM (Finite Element Method) model of the gear pump to compute the actual stresses and deformations of the housing. Third, the results of the structural response are used as excitation in a vibroacoustic sub-model to simulate the radiated noise using a high-order FEM technique. The comparison between the numerical and experimental flow curves validates the CFD model. The sound power calculations from the vibroacoustic model show good comparison with the sound intensity measurements around the pump casing, confirming the validity of the proposed coupled model. The described CFD-FEM approach proves to be a powerful gear pump design tool: it provides a reliable estimate of gear pump working parameters such as fluid power and vibroacoustic characteristics, starting from the CAD (Computer-Aided Design) geometry of the components. Furthermore, being one of the first multi-domain simulation models of a gear pump, this work can be useful to researchers as a starting point to correlate the noise emitted with the internal flow in full 3D conditions. [ABSTRACT FROM AUTHOR]

In this work, a three-dimensional fluid-structural and vibro-acoustics coupled model of a gear pump is presented. Gear pumps represent the majority of the positive displacement machines used for flow generation in fluid power systems. Typically, the dynamics of gear pumps are dependent on the characteristics of the fluid dynamics inside the pump, which translates into vibrations to the housing. These vibrations then propagate to the surrounding medium and emit sound. The purpose of this study is to propose a three-dimensional fully integrated computational model to simulate the complete gear pump behaviour from the fluid dynamics to the structural vibrations, up to the vibroacoustic response. In this hybrid configuration, a transient CFD (Computational Fluid Dynamics) model is first developed to simulate the 3D flow field with a deforming and re-meshing approach to take into account the variation of the volume between the gears. Second, the internal pressure field calculated at each time step is then used as a loading into a structural FEM (Finite Element Method) model of the gear pump to compute the actual stresses and deformations of the housing. Third, the results of the structural response are used as excitation in a vibroacoustic sub-model to simulate the radiated noise using a high-order FEM technique. The comparison between the numerical and experimental flow curves validates the CFD model. The sound power calculations from the vibroacoustic model show good comparison with the sound intensity measurements around the pump casing, confirming the validity of the proposed coupled model. The described CFD-FEM approach proves to be a powerful gear pump design tool: it provides a reliable estimate of gear pump working parameters such as fluid power and vibroacoustic characteristics, starting from the CAD (Computer-Aided Design) geometry of the components. Furthermore, being one of the first multi-domain simulation models of a gear pump, this work can be useful to researchers as a starting point to correlate the noise emitted with the internal flow in full 3D conditions.

The computational model that is able to estimate the temperature distribution inside a solid specimen during the film boiling phase of immersion quenching (water entry) process has been presented in this paper. It is based on the prescribed initial temperatures of the solid specimen and the liquid quenchant. In addition, the turbulence effects have to be considered using the assumed turbulence kinetic energy value, i.e., the "frozen turbulence" approach, that remains constant thorough the simulation. The studied material is nickel alloy, Inconel 600, for which extensive experimental data are available. The work has been carried out using ANSYS Fluent computational fluid dynamics software and the methods for solution of Stefan problem by Eulerian two fluid VOF model. A satisfactory agreement between the experimental and the calculated data has been achieved, yielding thereby the computationally obtained data that fit to a great extent the prescribed error band of ±10% during the estimated film boiling phase of the immersion quenching process itself. It was, however, found that the temperature calculated in the center of a specimen fits this error band until reaching somewhere t < 6 s due to low presumed turbulence level in the domain. In addition, the explosion of the vapor phase after the body reaches the free surface of the quenchant has also been successfully tracked using the numerical simulation model proposed herein. The major novelty of the present research lies in the fact that a moving boundary problem has been successfully resolved in conjunction with, to a great extent, basic-principle-based heat and mass transfer in a turbulent flow conjugate heat transfer (CHT) numerical simulation using moderate computational resources. [ABSTRACT FROM AUTHOR]

При численном моделировании процесса нарастания льда на поверхности обтекаемого тела важную роль играет задача геометрического перестроения поверхностной расчетной сетки согласно интенсивности ледообразования. В данной задаче по интенсивности нарастания льда в узлах или ячейках рассматриваемой сетки необходимо вычислить новые положения узлов сетки, чтобы получившаяся конфигурация эволюционировавшей расчетной сетки адекватно отражала поверхность с образовавшимся на ней ледяным покровом. Одним из критичных требований к алгоритму перестроения сетки является его надежность, возможность работать с произвольными поверхностными сетками, способность работать с сильными изгибами сетки, складками и шумами, а также бороться с потенциальными самопересечениями. В данной статье рассматривается алгоритм перестроения поверхностной сетки, в котором новое положение узла расчетной сетки определяется как точка пересечения траектории движения узла и общей огибающей семейства сфер с центрами в точках роста льда и радиусами, соответствующими интенсивности роста льда. Предложенный алгоритм предназначен для работы с телами со сложной геометрией, при его использовании происходит затягивание локальных впадин, а также сглаживание острых пиков, что повышает качество итоговой сетки. Основным качеством разработанного алгоритма является его надежность, что позволяет ему работать с сетками произвольной сложности и с сетками, обладающими геометрическими дефектами.

A sequence of 3D models generated using volumetric capture has the advantage of retaining the characteristics of dynamic objects and scenes. However, in volumetric data, since 3D mesh and texture are synthesized for every frame, the mesh of every frame has a different shape, and the brightness and color quality of the texture is various. This paper proposes an algorithm to consistently create a mesh of 4D volumetric data using dynamic reconstruction. The proposed algorithm comprises remeshing, correspondence searching, and target frame reconstruction by key frame deformation. We make non-rigid deformation possible by applying the surface deformation method of the key frame. Finally, we propose a method of compressing the target frame using the target frame reconstructed using the key frame with error rates of up to 98.88% and at least 20.39% compared to previous studies. The experimental results show the proposed method's effectiveness by measuring the geometric error between the deformed key frame and the target frame. Further, by calculating the residual between two frames, the ratio of data transmitted is measured to show a compression performance of 18.48%. [ABSTRACT FROM AUTHOR]

A multiscale crack iteration and remeshing model was proposed and implemented to predict the low-cycle crack propagation behavior for steel. Crack propagation behavior was quantified by fatigue indicator parameters (FIPs) in the crystal plasticity model. Once the crack propagation rate and direction were determined in the grain, the crack seam was inserted into the model by remeshing in postprocessing. To further relax the fatigue driving force and reduce the impact of FIP variation, an iteration procedure, in which sufficient computational cycles were preselected and iterated during the simulation, was applied to the mesoscale model. Additionally, the boundary conditions of the mesoscale model were obtained from the macroscale model by the multiscale simulation method. A three-point bending fatigue test was carried out to validate the iteration and remeshing model. The experimental results showed two cracks generated from the upper and lower surfaces during the fatigue test, and the crack propagation rate increased as the crack grew toward the center region. Meanwhile, the numerical model, including two initiated cracks, was implemented corresponding to the central region in the experimental specimen. By applying the boundary condition from the macroscale simulation associated with the experiment, the two cracks grew during the iteration and remeshing. The simulation results showed two cracks growing gradually toward the region with a reasonable number of cycles. The zigzag pattern simulated from the mesoscale model also qualitatively correlates well with the observation from experimental results. [ABSTRACT FROM AUTHOR]

Tessellating CAD models into triangular meshes is a long-lasting problem. Size field is widely used to accommodate varieties of requirements in remeshing, and it is usually discretized and optimized on a prescribed background mesh and kept constant in the subsequent remeshing procedure. Instead, we propose optimizing the size field on the current mesh, then using it as guidance to generate the next mesh. This simple strategy eliminates the need of building a proper background mesh and greatly simplifies the size field query. For better quality and convergence, we also propose a geodesic distance based initialization and adaptive re-weighting strategy in size field optimization. Similar to existing methods, we also view the remeshing of a CAD model as the remeshing of its parameterization domain, which guarantees that all the vertices lie exactly on the CAD surfaces and eliminates the need for costly and error-prone projection operations. However, for vertex smoothing which is important for mesh quality, we carefully optimize the vertex's location in the parameterization domain for the optimal Delaunay triangulation condition, along with a high-order cubature scheme for better accuracy. Experiments show that our method is fast, accurate and controllable. Compared with state-of-the-art methods, our approach is fast and usually generates meshes with smaller Hausdorff error, larger minimal angle with a comparable number of triangles. • A novel framework for alternative size field optimization and meshing. • Size field optimization with a penalty, initialization and re-weighting strategies. • Parameterization domain vertex smoothing with an accurate ODT condition on the surface. [ABSTRACT FROM AUTHOR]

Abstract With the development of biomolecular modeling and simulation, especially implicit solvent modeling, higher requirements are set for the stability, efficiency and mesh quality of molecular mesh generation software. In this review, we summarize the recent works in biomolecular mesh generation and molecular visualization. First, we introduce various definitions of molecular surface and corresponding meshing software. Second, as the mesh quality significantly influences biomolecular simulation, we investigate some remeshing methods in the fields of computer graphics and molecular modeling. Then, we show the application of biomolecular mesh in the boundary element method (BEM) and the finite element method (FEM). Finally, to conveniently visualize the numerical results based on the mesh, we present two types of molecular visualization systems.

The simulation of large structural deformations with the finite element method poses several challenges. The severe distortion of elements may deteriorate the accuracy and robustness of the method and restrict it to smaller deformations than desired. This issue is especially present in the finite cell method (FCM), where complex geometries are discretized with a non-conforming Cartesian grid introducing a fictitious material with very low stiffness. The remeshing strategy presented here improves the robustness at the cost of generating a new Cartesian grid of the deformed geometry at load steps where the element distortion becomes critical. This allows us to use larger load steps and to further deform the structure under consideration. We use radial basis functions to transfer the displacements and the displacement gradients from one mesh to the next one. The method is investigated in combination with a hyperelastic material and exemplary applied to simulate a pore of a foam. [ABSTRACT FROM AUTHOR]

Multiple crack propagation and coalescence in two-dimensional linear elastic media were modeled using the finite-element method (FEM) in conjunction with the subregion generalized variational principle. The proposed approach computes the stress intensity factor (SIF) accurately, as proved in a previous work. The approach results in regular geometric meshes. A multiple crack propagation scheme was developed in this study. The scheme follows the crack propagation by moving just the complementary energy subregion on the basis of the regular mesh. Consequently, it requires only minimal local remeshing without affecting most of the existing mesh. The scheme can handle crack coalescence easily. These advantages simplify the modeling and thus improve the efficiency. Four numerical examples, including a structure containing 10 cracks, were investigated to demonstrate the accuracy and efficiency of the proposed approach. [ABSTRACT FROM AUTHOR]

Although the flow drill screw (FDS) joining technique has been successfully used for connecting dissimilar materials in lightweight structures design, forming simulation of the FDS joining process is still challenging, due to the fact that modeling of the severe plastic deformation and material failure is still difficult. In this work, the FDS forming process was successfully simulated through an optimized remeshing method for joining of the DP590/Al6061-T6 in lap structure as a case study. The effectiveness and accuracy of the numerical model developed in the current study were compared with those of the model based on the Lagrangian method and calibrated by experimental data. The results show that the FDS process can be simulated accurately through remeshing the distorted elements to regular tetrahedral elements, with accurate petal, bushing, and thread formed. And the local temperature rising surrounding the screw and axial force change of the FDS process were also predicted accurately. The simulation precision of the forming of the petal and bushing and the peak temperature are 95% and 2%, while the error of the first peak force is 19.3%. It was found that the forming of the petal and bushing is under the axial extrusion force, whereas the forming of the thread is under the plane extrusion force. [ABSTRACT FROM AUTHOR]

For the large deformation and distortion of the mesh on the numerical simulation of rubber,using the solving and transformation between grids of the adaptive technique of Abaqus software,the rubber model was remeshed several times. In this paper,the key parts of the packer were used as the research object and the final rubber deformation results were obtained by two remeshing before solving the mapping to the new mesh for further solving. The results of numerical simulation show that remeshing can reduce the occurrence of distortion and solve the problem of nonlinear analysis of large deformation caused by mesh distortion.Remeshing can improve the accuracy of data transmission between the old and new grid when the old mesh has a smaller distortion. It provides a significant research method for the sealing performance of the rubber,which also has some reference value for other hyperelastic materials.

In numerical analyses based on unstructured meshes represented by the finite element method, quadrilateral and hexa-hedral meshes are used for a two-dimensional and a three-dimensional analyses, respectively, from the viewpoint of calculation accuracy and computation time. However, a method for automatically generating quadrilateral and hexahedral meshes has not been established thus far; in addition, a considerable amount of effort is required to perform manual mesh modifications. Mesh generation based on the frame field method is an effective technique to extract high quality quadrilateral and hexahedral meshes through the optimization of the posture of a frame with rotational symmetry. This method needs to solve a mixed-integer programming (MIP) problem while extracting the quadrilateral and hexahedral mesh using integer grid maps. When solving an MIP using a greedy method, solving a simultaneous equation is required approximately O(M) times, where M is the number of integer constraints. In this study, we propose a method to obtain a quadrilateral mesh by solving a simultaneous equation approximately O(1) times. In this method, the frame field is calculated using finite element discretization, and the finite element mesh is appropriately remeshed to be aligned with the integer grid resulting from the frame field optimization. The proposed method can reduce the amount of computation required to obtain integer grid maps for mesh extraction, without impairing the mesh quality. The proposed method is evaluated with respect to by mesh quality using the aspect ratio and the scaled Jacobian. Numerical examples demonstrate that the mesh quality is comparable to or better than that produced by conventional methods and manual procedures.

• We propose an efficient and practical method to do bounded-error remeshing. • If vertices are added into the mesh, the error is easily reduced and finally bounded. • We adaptively refine the mesh to satisfy the error-bounded constraint. • We alternately do remeshing based on an edge length field and adaptively adjust it. We propose an efficient and practically robust method to isotropically remesh an input triangular mesh with bounded approximation error. Our method is based on a key observation, that is, when more uniformly distributed vertices are added into the remeshed mesh, the error-bounded constraint is usually satisfied. Then our algorithm adaptively refines the remeshed mesh to satisfy the error-bounded constraint and avoid heavy computational load. To that end, we present an iterative approach that alternates in each iteration a pass to do an edge-based remeshing using the computed edge length field and a pass to adaptively adjust the edge length field. The robustness of our method is demonstrated by performing tests on complex shapes, as well as models containing sharp features or boundaries. Compared to the state-of-the-art error-bounded methods, our technique is much faster and more practically robust. [ABSTRACT FROM AUTHOR]

This review paper presents an overview of Vortex Methods for flow simulation and their different sub-approaches, from their creation to the present. Particle methods distinguish themselves by their intuitive and natural description of the fluid flow as well as their low numerical dissipation and their stability. Vortex methods belong to Lagrangian approaches and allow us to solve the incompressible Navier-Stokes equations in their velocity-vorticity formulation. In the last three decades, the wide range of research works performed on these methods allowed us to highlight their robustness and accuracy while providing efficient computational algorithms and a solid mathematical framework. On the other hand, many efforts have been devoted to overcoming their main intrinsic difficulties, mostly relying on the treatment of the boundary conditions and the distortion of particle distribution. The present review aims to describe the Vortex methods by following their chronological evolution and provides for each step of their development the mathematical framework, the strengths and limits as well as references to applications and numerical simulations. The paper ends with a presentation of some challenging and very recent works based on Vortex methods and successfully applied to problems such as hydrodynamics, turbulent wake dynamics, sediment or porous flows.

In this paper a new approach for merging overlapping grids for CFD simulations is presented. The proposed strategy is a preprocessor that integrates the overset meshes into a single mesh suitable for unstructured finite volume vertex-centered Navier–Stokes solvers. This strategy aims to deal with complex industrial problems, specially in case of moving components and overlapping boundary layers. The algorithm consists of two key steps: the definition of a hole cutting area over each component mesh, where nodes of the other mesh are removed, and the subsequent remeshing of the gap generated between both meshes. In this process, the first issue is particularly critical and it employs auxiliary coarse Cartesian meshes to simplify the involved computations like wall distance calculations or point inclusion test. The proposed approach has been demonstrated on 2D test configurations using the DLR-TAU solver [ABSTRACT FROM AUTHOR]

The remeshing technique has been proved to be useful in saving numerous elements for two-dimensional finite element crack closure analysis. The computer code employing this technique was further developed for three-dimensional problems. Using this technique, the crack closure phenomenon of specimens with various thicknesses was studied, with emphases on the closure transition from specimen surface to deep interior locations. It was found that, at the specimen surface, the loading-direction stress distribution, and the crack tip plastic zone differ from those obtained under plane stress condition. However, the surface and the plane stress opening stresses are close. When a specimen is thick enough, the stress state, plastic zone and crack opening stresses at the deep interior locations are close to those under plane strain condition. The surface effects on crack opening behavior reach to a depth that is approximately 1.34 times of the Irwin’s plane stress plastic zone size. [ABSTRACT FROM AUTHOR]

In this paper, a method to carry out the finite strain elastic-plastic analysis using a remeshing technique is presented. When the remeshing is performed, deformation history dependent physical quantities that are stored at the integration points of finite elements need to be transferred to those of the refined finite elements. Such operations are generally performed based on the shape functions of the finite elements. A typical procedures are that i) the strain history dependent quantities are assigned at the nodal points and ii) interpolations are performed by the shape functions. Such processes assume that the sizes and the arrangements of finite elements change moderately after the remesh. We are aiming at developing a methodology that allows drastic changes in mesh arrangements and sizes and in even kinds of finite elements when the remeshing is carried out. We propose a method that the deformation history dependent physical quantities are stored at points independent of the finite element mesh. They move along with the deformation of the solid. The physical quantities at the points evolve in a Lagrange manner. We name such points to be Mesh-independent Data Points (MDPs). The MDPs take the function to store the physical quantities whereas the finite element mesh takes that of performing the numerical integration. Necessary variables are mapped between the MDPs and the finite element. We call proposed technique to be MDP-Finite Element Method (MDP-FEM). This paper describes the concept of the MDP-FEM and numerical implementations are discussed first. Then, the analyses of diffused necking of tensile bars are presented for a demonstrative purpose. [ABSTRACT FROM AUTHOR]

The varying mesh technique avoiding redundant elements has been proved to be computation efficient in finite element crack closure analysis. Because the element model varies every cycle, the calculated information has to be mapped from the old to the new model. The results of this new technique are highly related to the mapped stress quality. In this study, the causes that the mapped stress quality can be improved solely by good remeshing arrangements are studied. A hybrid technique combining the new and conventional techniques is proposed. It is found that this hybrid technique may further improve the calculated results. [ABSTRACT FROM AUTHOR]

Morphing is a geometric interpolation technique that is often used by the animation industry to transform one form into another seemingly seamlessly. It does this by producing a large number of ‘intermediate’ forms between the two ‘extreme’ or ‘parent’ forms. It has already been shown that morphing technique can be a powerful tool for form design and as such can be a useful addition to the armoury of product designers. Morphing procedure itself is simple and consists of straightforward linear interpolation. However, establishing the correspondence between vertices of the parent models is one of the most difficult and important tasks during a morphing process. This paper discusses the mesh-merging method employed for this process as against the already established mesh-regularising method. It has been found that the merging method minimises the need for manual manipulation, allowing automation to a large extent.

Solution verification is the process of verifying the solution of a finite element analysis by performing a series of analyses on meshes of increasing mesh densities, to determine if the solution is converging. Solution verification has historically been too expensive, relying upon refinement templates resulting in an 8X multiplier in the number of elements. For even simple convergence studies, the 8X and 64X meshes must be solved, quickly exhausting computational resources. In this paper, we introduce Mesh Scaling, a new global mesh refinement technique for building series of all-hexahedral meshes for solution verification, without the 8X multiplier. Mesh Scaling reverse engineers the block decomposition of existing all-hexahedral meshes followed by remeshing the block decomposition using the original mesh as the sizing function multiplied by any positive floating number (e.g. 0.5X, 2X, 4X, 6X, etc.), enabling larger series of meshes to be constructed with fewer elements, making solution verification tractable. [ABSTRACT FROM AUTHOR]

A crack initiation and propagation algorithm driven by non-local ductile damage is proposed in a three-dimensional finite strain framework. The evolution of plastic strain and stress triaxiality govern a non-local ductile damage field via constitutive equations. When the damage reaches a critical threshold, a discontinuity in the form of a crack surface is inserted into the three-dimensional continuum. The location and direction of the introduced discontinuity directly result from the damage field. Crack growth is also determined by the evolution of damage at the crack tip and the crack surface is adaptively extended in the computed direction. Frequent remeshing is used to computationally track the initiation and propagation of cracks, as well as to simultaneously maintain a good quality of the finite elements undergoing large deformations. This damage driven remeshing strategy towards fracture allows one to simulate arbitrary crack paths in three-dimensional evolving geometries. It has a significant potential for a wide range of industrial applications. Numerical examples are solved to demonstrate the ability of the proposed framework. [ABSTRACT FROM AUTHOR]

Remeshing is a fundamental problem in 3D modeling and computer aided design. Aiming at the shortcomings of the Euclidean distance measure in CVT method, we present a new topology preserving triangular remeshing algorithm. Two mesh quality measuring criterions are used in the algorithm for determining a new site insertion step: (1) a new mesh error metric; (2) the topology condition of restricted Voronoi cell of each site. While new sites are inserted, a flooding-based remeshing algorithm is called to optimize the location of all sites and achieve the remeshing results iteratively. Experimental results show that the new algorithm can preserve the topology of input mesh efficiently and get remeshing results with good quality than CVT method with Euclidean distance measure. [ABSTRACT FROM AUTHOR]

The Virtual Element Method is ideal for problems with non-conforming meshes since nodes can be inserted at the virtual element boundary to obtain a conforming mesh structure, without changing the ansatz of the element. The contact conditions can be employed on different enforcing strategies. This feature can be explored also for three-dimensional contact problems. In this work, we introduce a new framework, including a remeshing strategy, which leads to conforming meshes. Various numerical examples in 3D will be shown, including standard cases like the contact patch test and Hertzian contact. [ABSTRACT FROM AUTHOR]

567-meshes are a new type of closed and 2-manifold triangular meshes introduced by Aghdaii et al. in 2012 [1] . Vertices with valence less than 5 or greater than 7 are problematic for many mesh processing tasks such as edge collapse or surface subdivision. However, vertices with valence equal to 6 everywhere is most often impossible due to either surface topology or surface feature preservation, that is why 567-meshes are particularly of interest. This paper proposes a 567-remeshing algorithm that locally retriangulates the mesh considering vertex valence, vertex budget and mesh fidelity as a whole. This algorithm also offers the possibility to preserve a set of feature edges during remeshing. This results in a framework capable of low budget 567-remeshing where remeshed models have a much higher fidelity to the original surface compared to the state of the art. As applications of this work, we demonstrate that our remeshing improves the performances of mesh regularization and mesh connectivity compression. [ABSTRACT FROM AUTHOR]

Poisson-disk sampling is one of the fundamental research problems in computer graphics that has many applications. In this paper, we study the problem of maximal Poisson-disk sampling on mesh surfaces. We present a simple approach that generalizes the 2D maximal sampling framework to surfaces. The key observation is to use a subdivided mesh as the sampling domain for conflict checking and void detection. Our approach improves the state-of-the-art approach in efficiency, quality and the memory consumption. [ABSTRACT FROM AUTHOR]

Remeshing techniques seek to modify a mesh in order to adapt it to an specific application. This work proposes a remeshing methodology specialized in the human face, whose purpose is to reduce the number of faces and vertices that requires the mesh, keeping the characteristics of the human anatomy. Curvature information that highlights the intrinsic anisotropy of natural geometry or geometry of human origin is used to accomplish this. Results were polygonal anisotropic meshes, composed mainly of quadrilaterals, with less than 50% of the points and faces of the initial mesh, that maintain the anatomical features for models of the face in a neutral expression, or expressions of happiness, disgust, fear, angry, surprise, and sadness. The methodology was validated with models from the BU-3DFE database, and the quality of the obtained results were evaluated against the remeshing achieved when a technique of simplification based on quadric error metrics is used. [ABSTRACT FROM AUTHOR]