The Boundary Element Method Volume 2

This work presents a thorough treatment of boundary element methods (BEM) for solving strongly elliptic boundary integral equations obtained from boundary reduction of elliptic boundary value problems in $\mathbb{R}^3$. The book is self-contained, the prerequisites on elliptic partial differential and integral equations being presented in Chapters 2 and 3. The main focus is on the development, analysis, and implementation of Galerkin boundary element methods, which is one of the most flexible and robust numerical discretization methods for integral equations. For the efficient realization of the Galerkin BEM, it is essential to replace time-consuming steps in the numerical solution process with fast algorithms. In Chapters 5-9 these methods are developed, analyzed, and formulated in an algorithmic way.

The Boundary Element Method for Engineers and Scientists: Theory and Applications is a detailed introduction to the principles and use of boundary element method (BEM), enabling this versatile and powerful computational tool to be employed for engineering analysis and design. In this book, Dr. Katsikadelis presents the underlying principles and explains how the BEM equations are formed and numerically solved using only the mathematics and mechanics to which readers will have been exposed during undergraduate studies. All concepts are illustrated with worked examples and problems, helping to put theory into practice and to familiarize the reader with BEM programming through the use of code and programs listed in the book and also available in electronic form on the book’s companion website. Offers an accessible guide to BEM principles and numerical implementation, with worked examples and detailed discussion of practical applications This second edition features three new chapters, including coverage of the dual reciprocity method (DRM) and analog equation method (AEM), with their application to complicated problems, including time dependent and non-linear problems, as well as problems described by fractional differential equations Companion website includes source code of all computer programs developed in the book for the solution of a broad range of real-life engineering problems

The boundary element method (BEM) is a modern numerical technique, which has enjoyed increasing popularity over the last two decades, and is now an established alternative to traditional computational methods of engineering analysis. The main advantage of the BEM is its unique ability to provide a complete solution in terms of boundary values only, with substantial savings in modelling effort. This two-volume book set is designed to provide the readers with a comprehensive and up-to-date account of the boundary element method and its application to solving engineering problems. Each volume is a self-contained book including a substantial amount of material not previously covered by other text books on the subject. Volume 1 covers applications to heat transfer, acoustics, electrochemistry and fluid mechanics problems, while volume 2 concentrates on solids and structures, describing applications to elasticity, plasticity, elastodynamics, fracture mechanics and contact analysis. The early chapters are designed as a teaching text for final year undergraduate courses. Both volumes reflect the experience of the authors over a period of more than twenty years of boundary element research. This volume, Applications in Solids and Structures, provides a comprehensive presentation of the BEM from fundamentals to advanced engineering applications and encompasses: Elasticity for 2D, 3D and Plates and Shells Non-linear, Transient and Thermal Stress Analysis Crack Growth and Multi-body Contact Mechanics Sensitivity Analysis and Optimisation Analysis of Assembled Structures. An important feature of this book is the in-depth presentation of BEM formulations in all the above fields, including detailed discussions of the basic theory, numerical algorithms and where possible simple examples are included, as well as test results for practical engineering applications of the method. Although most of the methods presented are the latest developments in the field, the author has included some simple techniques, which are helpful in understanding the computer implementation of BEM. Another notable feature is the comprehensive presentation of a new generation of boundary elements known as the Dual Boundary Element Method. Written by an internationally recognised authority in the field, this is essential reading for postgraduates, researchers and practitioners in Aerospace, Mechanical and Civil Engineering and Applied Mathematics.

Over the past decades, the Boundary Element Method has emerged as a ver satile and powerful tool for the solution of engineering problems, presenting in many cases an alternative to the more widely used Finite Element Method. As with any numerical method, the engineer or scientist who applies it to a practical problem needs to be acquainted with, and understand, its basic principles to be able to apply it correctly and be aware of its limitations. It is with this intention that we have endeavoured to write this book: to give the student or practitioner an easy-to-understand introductory course to the method so as to enable him or her to apply it judiciously. As the title suggests, this book not only serves as an introductory course, but also cov ers some advanced topics that we consider important for the researcher who needs to be up-to-date with new developments. This book is the result of our teaching experiences with the Boundary Element Method, along with research and consulting activities carried out in the field. Its roots lie in a graduate course on the Boundary Element Method given by the authors at the university of Stuttgart. The experiences gained from teaching and the remarks and questions of the students have contributed to shaping the 'Introductory course' (Chapters 1-8) to the needs of the stu dents without assuming a background in numerical methods in general or the Boundary Element Method in particular.

A substantial amount of research on Boundary Elements has taken place since publication of the first Volume of this series. Most of the new work has concentrated on the solution of non-linear and time dependent problems and the development of numerical techniques to increase the efficiency of the method. Chapter 1 of this Volume deals with the solution of non-linear potential problems, for which the diffusivity coefficient is a function of the potential and the boundary conditions are also non-linear. The recent research reported here opens the way for the solution of a: large range of non-homogeneous problems by using a simple transformation which linearizes the governing equations and consequently does not require the use of internal cells. Chapter 2 summarizes the main integral equations for the solution of two-and three dimensional scalar wave propagation problems. This is a type of problem that is well suited to boundary elements but generally gives poor results when solved using finite elements. The problem of fracture mechanics is studied in Chapter 3, where the ad vantages of using boundary integral equations are demonstrated. One of the most interesting features of BEM i~ the possibility of describing the problem only as a function of the boundary unknowns, even in the presence of body, centrifugal and temperature induced forces. Chapter 4 explains how this can be done for two-and three-dimensional elastostatic problems.

This thorough yet understandable introduction to the boundary element method presents an attractive alternative to the finite element method. It not only explains the theory but also presents the implementation of the theory into computer code, the code in FORTRAN 95 can be freely downloaded. The book also addresses the issue of efficiently using parallel processing hardware in order to considerably speed up the computations for large systems. The applications range from problems of heat and fluid flow to static and dynamic elasto-plastic problems in continuum mechanics.

The boundary element method (BEM) is now a well-established numerical technique which provides an efficient alternative to the prevailing finite difference and finite element methods for the solution of a wide range of engineering problems. The main advantage of the BEM is its unique ability to provide a complete problem solution in terms of boundary values only, with substantial savings in computer time and data preparation effort. An initial restriction of the BEM was that the fundamental solution to the original partial differential equation was required in order to obtain an equivalent boundary in tegral equation. Another was that non-homogeneous terms accounting for effects such as distributed loads were included in the formulation by means of domain integrals, thus making the technique lose the attraction of its "boundary-only" character. Many different approaches have been developed to overcome these problems. It is our opinion that the most successful so far is the dual reciprocity method (DRM), which is the subject matter of this book. The basic idea behind this approach is to employ a fundamental solution corresponding to a simpler equation and to treat the remaining terms, as well as other non-homogeneous terms in the original equation, through a procedure which involves a series expansion using global approximating functions and the application of reciprocity principles.