Download or read book Quadrilateral Finite Element Mesh Coarsening written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Techniques for coarsening a quadrilateral mesh are described. These techniques include identifying a coarsening region within the quadrilateral mesh to be coarsened. Quadrilateral elements along a path through the coarsening region are removed. Node pairs along opposite sides of the path are identified. The node pairs along the path are then merged to collapse the path.

Download or read book Quadrilateral hexahedral Finite Element Mesh Coarsening written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A technique for coarsening a finite element mesh ("FEM") is described. This technique includes identifying a coarsening region within the FEM to be coarsened. Perimeter chords running along perimeter boundaries of the coarsening region are identified. The perimeter chords are redirected to create an adaptive chord separating the coarsening region from a remainder of the FEM. The adaptive chord runs through mesh elements residing along the perimeter boundaries of the coarsening region. The adaptive chord is then extracted to coarsen the FEM.

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 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 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 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 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 Finite Element Mesh Generation written by B. H. V. Topping and published by Saxe-Coburg Publications. This book was released on 2004 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;This book describes both structured and unstructured mesh generation techniques. Structured mesh generation is covered briefly and the algebraic, multi-block technique is discussed in more detail. The main part of the book covers unstructured mesh generation using the advancing front, paving and Delaunay techniques. The Delaunay method is described in two and three dimensions. Both theoretical and implementation issues are discussed in detail. An integrated framework that is used for the two dimensional unstructured methods is also described. Common features of the framework include: accurate control over mesh size; boundary refinement procedures; and postprocessing tasks such as smoothing. Methods to convert triangular meshes to quadrilateral meshes are also presented. Mesh quality of the different mesh generation procedures is addressed with some examples.". "The book will be of interest to engineers, computer scientists and mathematicians working on mesh generation and finite element methods. The C source code for the procedures described in the book is available via the authors's website."--BOOK JACKET.

Download or read book Development of a Two dimensional Finite Element Mesh Generator with Automatic Mesh Refinement Using Quadrilateral Elements and Bezier Curve Boundary Definition written by Jeffrey A. Talbert and published by . This book was released on 1987 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A New Quadrilateral Finite Element Mesh Generator written by Miguel A. Gutiérrez de la Merced and published by . This book was released on 1993 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the 22nd International Meshing Roundtable written by Josep Sarrate and published by Springer Science & Business Media. This book was released on 2013-09-03 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the articles presented at the 22nd International Meshing Roundtable (IMR) organized, in part, by Sandia National Laboratories and was held on Oct 13-16, 2013 in Orlando, Florida, USA. The first IMR was held in 1992, and the conference series has been held annually since. Each year the 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 modeling, computer graphics and visualization.

Download or read book Conformal Refinement of Unstructured Quadrilateral Meshes written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a multilevel adaptive refinement technique for unstructured quadrilateral meshes in which the mesh is kept conformal at all times. This means that the refined mesh, like the original, is formed of only quadrilateral elements that intersect strictly along edges or at vertices, i.e., vertices of one quadrilateral element do not lie in an edge of another quadrilateral. Elements are refined using templates based on 1:3 refinement of edges. We demonstrate that by careful design of the refinement and coarsening strategy, we can maintain high quality elements in the refined mesh. We demonstrate the method on a number of examples with dynamically changing refinement regions.

Download or read book Automatic Procedures in Evolutionary Finite Element Calculations written by Patrick F. Chavez and published by . This book was released on 1983 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book FINITE ELEMENT METHODS written by CHENNAKESAVA R. ALAVALA and published by PHI Learning Pvt. Ltd.. This book was released on 2008-11-10 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finite Element Methods form an indispensable part of engineering analysis and design. The strength of FEM is the ease and elegance with which it handles the boundary conditions. This compact and well-organized text presents a comprehensive analysis of Finite Element Methods (FEM). The book gives a clear picture of structural, torsion, free-vibration, heat transfer and fluid flow problems. It also provides detailed description of equations of equilibrium, stress-strain relations, interpolation functions and element design, symmetry and applications of FEM. The text is a synthesis of both the physical and the mathematical characteristics of finite element methods. A question bank at the end of each chapter comprises descriptive and objective type questions to drill the students in self-study. KEY FEATURES Includes step-by-step procedure to solve typical problems using ANSYS® software. Gives numerical problems in SI units. Elaborates shaper functions for higher-order elements. Furnishes a large number of worked-out examples and solved problems. This profusely illustrated, student-friendly text is intended primarily for undergraduate students of Mechanical/Production/Civil and Aeronautical Engineering. By a judicious selection of topics, it can also be profitably used by postgraduate students of these disciplines. In addition, practising engineers and scientists should find it very useful besides students preparing for competitive exams.

Download or read book Adaptive Finite Element Methods for Differential Equations written by Wolfgang Bangerth and published by Birkhäuser. This book was released on 2013-11-11 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: These Lecture Notes have been compiled from the material presented by the second author in a lecture series ('Nachdiplomvorlesung') at the Department of Mathematics of the ETH Zurich during the summer term 2002. Concepts of 'self adaptivity' in the numerical solution of differential equations are discussed with emphasis on Galerkin finite element methods. The key issues are a posteriori er ror estimation and automatic mesh adaptation. Besides the traditional approach of energy-norm error control, a new duality-based technique, the Dual Weighted Residual method (or shortly D WR method) for goal-oriented error estimation is discussed in detail. This method aims at economical computation of arbitrary quantities of physical interest by properly adapting the computational mesh. This is typically required in the design cycles of technical applications. For example, the drag coefficient of a body immersed in a viscous flow is computed, then it is minimized by varying certain control parameters, and finally the stability of the resulting flow is investigated by solving an eigenvalue problem. 'Goal-oriented' adaptivity is designed to achieve these tasks with minimal cost. The basics of the DWR method and various of its applications are described in the following survey articles: R. Rannacher [114], Error control in finite element computations. In: Proc. of Summer School Error Control and Adaptivity in Scientific Computing (H. Bulgak and C. Zenger, eds), pp. 247-278. Kluwer Academic Publishers, 1998. M. Braack and R. Rannacher [42], Adaptive finite element methods for low Mach-number flows with chemical reactions.

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 The Mathematics of Finite Elements and Applications X MAFELAP 1999 written by J.R. Whiteman and published by Elsevier. This book was released on 2000-06-26 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tenth conference on The Mathematics of Finite Elements and Applications, MAFELAP 1999, was held at Brunel University during the period 22-25 June, 1999. This book seeks to highlight certain aspects of the state-of-the-art theory and applications of finite element methods of that time.This latest conference, in the MAFELAP series, followed the well established MAFELAP pattern of bringing together mathematicians, engineers and others interested in the field to discuss finite element techniques.In the MAFELAP context finite elements have always been interpreted in a broad and inclusive manner, including techniques such as finite difference, finite volume and boundary element methods as well as actual finite element methods. Twenty-six papers were carefully selected for this book out of the 180 presentations made at the conference, and all of these reflect this style and approach to finite elements. The increasing importance of modelling, in addition to numerical discretization, error estimation and adaptivity was also studied in MAFELAP 1999.