Download or read book Automated All Quadrilateral Mesh Adaption Through Re nement and Coarsening written by and published by . This book was released on 2009 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Automated All quadrilateral Mesh Adaptation Through Refinement and Coarsening written by Bret Dallas Anderson and published by . This book was released on 2009 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a new approach to conformal all-quadrilateral mesh adaptation. In finite element modeling applications, it is often desirable to modify the node density of the mesh; increasing the density in some parts of the mesh to provide more accurate results, while decreasing the density in other parts to reduce computation time. The desired node density is typically determined by a sizing function based on either the geometry of the model or the results of a finite element solution. Although there are numerous mesh adaptation methods currently in use, including initial adaptive mesh generation, node redistribution, and adaptive mesh refinement, there are relatively few methods that modify the mesh density by adding and removing mesh elements, and none of these guarantee a conformal, all-quadrilateral mesh while allowing general coarsening. This work introduces a new method that incorporates both conformal refinement and coarsening strategies on an existing mesh of any density or configuration. Given a sizing function, this method modifies the mesh by combining existing template based quadrilateral refinement methods with recent developments in localized quadrilateral coarsening and quality improvement into an automated mesh adaptation routine.

Download or read book Proceedings of the 18th International Meshing Roundtable written by Brett W. Clark and published by Springer Science & Business Media. This book was released on 2009-11-26 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the articles presented at the 18th International Meshing Roundtable (IMR) organized, in part, by Sandia National Laboratories and held October 25-28, 2009 in Salt Lake City, Utah, USA. The volume presents recent results of mesh generation and adaptation which has applications to finite element simulation. It introduces theoretical and novel ideas with practical potential.

Download or read book Proceedings of the 17th International Meshing Roundtable written by Rao V. Garimella and published by Springer Science & Business Media. This book was released on 2008-10-23 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the articles presented at the 17th International Meshing Roundtable (IMR) organized, in part, by Sandia National Laboratories and held October 12-15, 2008. The volume presents recent results of mesh generation and adaptation which has applications to finite element simulation. It introduces theoretical and novel ideas with practical potential.

Download or read book Finite Element Mesh Generation written by Daniel S.H. Lo and published by CRC Press. This book was released on 2015-01-15 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights the Progression of Meshing Technologies and Their Applications Finite Element Mesh Generation provides a concise and comprehensive guide to the application of finite element mesh generation over 2D domains, curved surfaces, and 3D space. Organised according to the geometry and dimension of the problem domains, it develops from the basic meshing algorithms to the most advanced schemes to deal with problems with specific requirements such as boundary conformity, adaptive and anisotropic elements, shape qualities, and mesh optimization. It sets out the fundamentals of popular techniques, including: Delaunay triangulation Advancing-front (ADF) approach Quadtree/Octree techniques Refinement and optimization-based strategies From the geometrical and the topological aspects and their associated operations and inter-relationships, each approach is vividly described and illustrated with examples. Beyond the algorithms, the book also explores the practice of using metric tensor and surface curvatures for generating anisotropic meshes on parametric space. It presents results from research including 3D anisotropic meshing, mesh generation over unbounded domains, meshing by means of intersection, re-meshing by Delaunay-ADF approach, mesh refinement and optimization, generation of hexahedral meshes, and large scale and parallel meshing, along with innovative unpublished meshing methods. The author provides illustrations of major meshing algorithms, pseudo codes, and programming codes in C++ or FORTRAN. Geared toward research centers, universities, and engineering companies, Finite Element Mesh Generation describes mesh generation methods and fundamental techniques, and also serves as a valuable reference for laymen and experts alike.

Download or read book Proceedings of the 20th International Meshing Roundtable written by William Roshan Quadros and published by Springer Science & Business Media. This book was released on 2011-12-06 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the articles presented at the 20th International Meshing Roundtable (IMR) organized, in part, by Sandia National Laboratories and was held in Paris, France on Oct 23-26, 2011. This is the first year the IMR was held outside the United States territory. Other sponsors of the 20th IMR are Systematic Paris Region Systems & ICT Cluster, AIAA, NAFEMS, CEA, and NSF. The Sandia National Laboratories started the first IMR in 1992, and the conference has been held annually since. Each year the IMR brings together researchers, developers, and application experts, from a variety of disciplines, to present and discuss ideas on mesh generation and related topics. The topics covered by the IMR have applications in numerical analysis, computational geometry, computer graphics, as well as other areas, and the presentations describe novel work ranging from theory to application.

Download or read book Automated Quadrilateral Coarsening by Ring Collapse written by Mark William Dewey and published by . This book was released on 2008 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: In most finite element analysis, a uniform mesh is not the optimum way to model the problem. Mesh adaptation is the ability to modify a finite element model to include regions of the mesh with higher and lower node density. Mesh adaptation has received extensive study in both computational mechanics and computer graphics to increase the resolution or accuracy of the solution in specific areas. The algorithm developed in this thesis, the Automated Quadrilateral Coarsening by Ring Collapse (AQCRC) algorithm, provides a unique solution to allow conformal coarsening of both structured and unstructured quadrilateral finite element meshes. The algorithm is based on dual chord operations and dual chord removal. The AQCRC algorithm follows six steps: 1) input of a coarsening region and factor, 2) selection of coarsening rings, 3) improvement of mesh quality, 4) removal of coarsening rings, 5) mesh clean-up and 6) coarsening iterations. Examples are presented that show the application of the algorithm.

Download or read book Computational Geomechanics and Hydraulic Structures written by Sheng-Hong Chen and published by Springer. This book was released on 2018-06-21 with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent research into developing and applying computational tools to estimate the performance and safety of hydraulic structures from the planning and construction stage to the service period. Based on the results of a close collaboration between the author and his colleagues, friends, students and field engineers, it shows how to achieve a good correlation between numerical computation and the actual in situ behavior of hydraulic structures. The book’s heuristic and visualized style disseminates the philosophy and road map as well as the findings of the research. The chapters reflect the various aspects of the three typical and practical methods (the finite element method, the block element method, the composite element method) that the author has been working on and made essential contributions to since the 1980s. This book is an advanced continuation of Hydraulic Structures by the same author, published by Springer in 2015.

Download or read book 27th International Meshing Roundtable written by Xevi Roca and published by Springer. This book was released on 2019-07-01 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Meshing Roundtable (IMR) brings together researchers, developers, and application experts in a variety of disciplines, from all over the world, to present and discuss ideas on mesh generation and related topics. The technical papers in this volume present theoretical and novel ideas and algorithms with practical potential, as well as technical applications in science and engineering, geometric modelling, computer graphics, and visualization.

Download or read book An Introduction to Element Based Galerkin Methods on Tensor Product Bases written by Francis X. Giraldo and published by Springer Nature. This book was released on 2020-10-30 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to solving partial differential equations (PDEs) numerically using element-based Galerkin methods. Although it draws on a solid theoretical foundation (e.g. the theory of interpolation, numerical integration, and function spaces), the book’s main focus is on how to build the method, what the resulting matrices look like, and how to write algorithms for coding Galerkin methods. In addition, the spotlight is on tensor-product bases, which means that only line elements (in one dimension), quadrilateral elements (in two dimensions), and cubes (in three dimensions) are considered. The types of Galerkin methods covered are: continuous Galerkin methods (i.e., finite/spectral elements), discontinuous Galerkin methods, and hybridized discontinuous Galerkin methods using both nodal and modal basis functions. In addition, examples are included (which can also serve as student projects) for solving hyperbolic and elliptic partial differential equations, including both scalar PDEs and systems of equations.

Download or read book Low Singularity Quadrilateral Meshes for Numerical Simulations written by Chaman Singh Verma and published by . This book was released on 2017 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Triangle and quadrilateral meshes are two common ways discretize 2D domains, and 3D surfaces. Despite many inherent theoretical advantages of quadrilateral meshes, triangular meshes are more widely used for the following reasons: (1) there are many well-known triangle mesh generating algorithms that are fast, parameters-free, and robust, and (2) triangular meshes are easy to modify and optimize. The main contributions of this thesis are new theoretical results, and associated algorithms that demonstrate that one can rapidly generate high quality quadrilateral meshes, and modify them as easily. Specifically, the thesis describes the following four concepts specifically related to quadrilateral meshes. ·Perfect-Matching Triangulation to Quadrangulation Conversion: Converting a triangle mesh to a quadrilateral mesh, with perfect matching (i.e., with no dangling triangles), is of significant interest. Current perfect-matching algorithms are variations of Edmond's classic Blossom algorithm. One variation is the tree-percolation algorithm that utilizes the binary tree dual of a triangular mesh. This algorithm is extremely fast, but does not guarantee perfect matching. In this thesis, I show how the tree-percolation algorithm can be modified to result in perfect matching, without sacrificing on speed. To the best of my knowledge, the proposed tree percolation with flipping (TPF) is the fastest algorithm today to convert a triangular mesh into a quadrilateral mesh with perfect matching. As with any perfect matching algorithm, the topological quality of the quadrilateral mesh is often very poor, and the resulting quadrilateral mesh cannot be used for simulation. However, it is often used as an initial quadrilateral mesh for further improvement. ·Minimum Singularity Templates: Improving a quadrilateral mesh means improving both the geometric and topological qualities. Local improvements of a quadrilateral mesh are almost impossible since modifying a single element can have a global effect on the mesh (unlike in triangular meshes). While several non-local methods have been proposed, most of these focus on geometric quality, and often sacrifice on topological quality. This thesis introduces the concept of minimum singularity templates (MST) that address both qualities simultaneously. The MST aims to reduce the number of singularities in an existing quadrilateral mesh in a systematic manner, while maintaining geometric quality. ·Unified Quad Mesh Adaptation Technique: Mesh adaptation refers to the task of refining, coarsening or improving a mesh. It plays a critical role in balancing computational efficiency and numerical accuracy in various applications. Currently, different methods have been proposed for each of these three adaptations, and they all invariably reduce the topological quality of the mesh. In this thesis, a unified concept of "alpha" MST template is introduced, where a single parameter "alpha" is used to achieve all three forms of adaptations. With "alpha = 1", we would improve the quality of the mesh, with "alpha 1" we would simplify the mesh, and "alpha 1" would refine the mesh. Furthermore, the proposed unified algorithm will not deteriorate the topological quality. ·An Ab-initio Quad Mesh Generator: Exploiting the concept of MST, the thesis describes a new indirect method for ab-initio generating quadrilateral meshes. The proposed combinatorial quadrilateral mesh generation (CQMG) algorithm is robust and fast (capable of generating millions of elements per second. The underlying reason is that CQMG uses simple algebraic checks, instead of expensive exact geometric predicates. The speed and robustness are demonstrated through numerous examples, and compared against other popular algorithms.

Download or read book Discretization Methods in Structural Mechanics written by Günther Kuhn and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advent of the digital computer has given great impetus to the development of modern discretization methods in structural mechanics. The young history of the finite element method (FEM) reflects the dramatic increase of computing speed and storage capacity within a relatively short period of time. The history of the boundary element method (BEM) is still younger. Presently, intense scientific efforts aimed at extending the range of application of the BEM can be observed. More than 10 years ago, O.C. Zienkiewicz and his co-workers published the first papers on the coupling of FE and BE discretizations of subregions of solids for the purpose of exploiting the complementary advantages of the two discretization methods and reducing their disadvantages. The FEM has revolutionized structural analysis in industry as well as academia. The BEM has a fair share in the continuation of this revolution. Both discretization methods have become a domain of vigorous, world-wide research activities. The rapid increase of the number of specialized journals and scientific meetings indicates the remarkable increase of research efforts in this important subdolll.ain of computational ulechanics. Several discussions of this situation in the Committee for Discretization Methods ill Solid Mechanics of the Society for Applied Mathematics and Mechanics (GAMM) resulted in the plan to submit a proposal to the General Assembly of the International Union of Theoretical and Applied Mechanics (IUTAM) to sponsor a pertinent IUTAM Symposium.

Download or read book Reactive Flows Diffusion and Transport written by Willi Jäger and published by Springer Science & Business Media. This book was released on 2007-05-31 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles in this volume summarize the research results obtained in the former SFB 359 "Reactive Flow, Diffusion and Transport" which has been supported by the DFG over the period 1993-2004. The main subjects are physical-chemical processes sharing the difficulty of interacting diffusion, transport and reaction which cannot be considered separately. The modeling and simulation within this book is accompanied by experiments.

Download or read book Localized Coarsening of Conforming All hexahedral Meshes written by Adam C. Woodbury and published by . This book was released on 2008 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finite element mesh adaptation methods can be used to improve the efficiency and accuracy of solutions to computational modeling problems. For many finite element modeling applications, a conforming all-hexahedral mesh is preferred. When adapting a hexahedral mesh, localized modifications that preserve topologic conformity are often desired. Effective hexahedral refinement methods that satisfy these criteria have recently become available. However, due to hexahedral mesh topology constraints, little progress has been made in the area of hexahedral coarsening. This thesis presents a new method to locally coarsen conforming all-hexahedral meshes. The method works on both structured and unstructured meshes and is not based on undoing previous refinement. Building upon recent developments in quadrilateral coarsening, the method utilizes hexahedral sheet and column operations, including pillowing, column collapsing, and sheet extraction. A general algorithm for automated coarsening is presented and examples of models that have been coarsened are shown. While results are promising, further work is needed to improve the automated process.

Download or read book Enhanced Mesh Adaptation Using Localized Conformal Quadrilateral and Hexahedral Coarsening written by and published by . This book was released on 2008 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1994 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fermentation Processes Engineering in the Food Industry written by Carlos Ricardo Soccol and published by CRC Press. This book was released on 2013-03-27 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of modern tools of molecular biology and genetic engineering and new skills in metabolic engineering and synthetic biology, fermentation technology for industrial applications has developed enormously in recent years. Reflecting these advances, Fermentation Processes Engineering in the Food Industry explores the state of the art of