Olaf Steinbach

Boundary Element Methods (BEM) play an important role in modern numerical computations in the applied and engineering sciences. These methods turn out to be powerful tools for numerical studies of various physical phenomena which can be described mathematically by partial differential equations. The most prominent example is the potential equation (Laplace equation), which is used to model physical phenomena in electromagnetism, gravitation theory, and in perfect fluids. A further application leading to the Laplace equation is the model of steady state heat flow. One of the most popular applications of the BEM is the system of linear elastostatics, which can be considered in both bounded and unbounded domains. A simple model for a fluid flow, the Stokes system, can also be solved by the use of the BEM. The most important examples for the Helmholtz equation are the acoustic scattering and the sound radiation. The Fast Solution of Boundary Integral Equations provides a detailed description of fast boundary element methods which are based on rigorous mathematical analysis. In particular, a symmetric formulation of boundary integral equations is used, Galerkin discretisation is discussed, and the necessary related stability and error estimates are derived. For the practical use of boundary integral methods, efficient algorithms together with their implementation are needed. The authors therefore describe the Adaptive Cross Approximation Algorithm, starting from the basic ideas and proceeding to their practical realization. Numerous examples representing standard problems are given which underline both theoretical results and the practical relevance of boundary element methods in typical computations.

This book presents a unified theory of the Finite Element Method and the Boundary Element Method for a numerical solution of second order elliptic boundary value problems. This includes the solvability, stability, and error analysis as well as efficient methods to solve the resulting linear systems. Applications are the potential equation, the system of linear elastostatics and the Stokes system. While there are textbooks on the finite element method, this is one of the first books on Theory of Boundary Element Methods. It is suitable for self study and exercises are included.

This book presents a unified theory of the Finite Element Method and the Boundary Element Method for a numerical solution of second order elliptic boundary value problems. This includes the solvability, stability, and error analysis as well as efficient methods to solve the resulting linear systems. Applications are the potential equation, the system of linear elastostatics and the Stokes system. While there are textbooks on the finite element method, this is one of the first books on Theory of Boundary Element Methods. It is suitable for self study and exercises are included.

Boundary Element Methods (BEM) play an important role in modern numerical computations in the applied and engineering sciences. These methods turn out to be powerful tools for numerical studies of various physical phenomena which can be described mathematically by partial differential equations. The most prominent example is the potential equation (Laplace equation), which is used to model physical phenomena in electromagnetism, gravitation theory, and in perfect fluids. A further application leading to the Laplace equation is the model of steady state heat flow. One of the most popular applications of the BEM is the system of linear elastostatics, which can be considered in both bounded and unbounded domains. A simple model for a fluid flow, the Stokes system, can also be solved by the use of the BEM. The most important examples for the Helmholtz equation are the acoustic scattering and the sound radiation. The Fast Solution of Boundary Integral Equations provides a detailed description of fast boundary element methods which are based on rigorous mathematical analysis. In particular, a symmetric formulation of boundary integral equations is used, Galerkin discretisation is discussed, and the necessary related stability and error estimates are derived. For the practical use of boundary integral methods, efficient algorithms together with their implementation are needed. The authors therefore describe the Adaptive Cross Approximation Algorithm, starting from the basic ideas and proceeding to their practical realization. Numerous examples representing standard problems are given which underline both theoretical results and the practical relevance of boundary element methods in typical computations.

Diese dreisemestrige Einfuhrung in die Analysis behandelt die Integral- und Differentialrechnung einer und mehrerer Veranderlicher. Daran anschliessend werden analytische und einfache numerische Verfahren zur Losung gewohnlicher Differentialgleichungen besprochen. Der letzte Teil ist Methoden der komplexen Funktionentheorie gewidmet. Zentrales Anliegen dieses Lehrbuches sind die Entwicklung und Anwendung von praktischen Methoden zur Losung mathematischer Aufgaben sowie die Konstruktion dieser Losungen.

Die Simulation technischer Prozesse erfordert in der Regel die Losung von linearen Gleichungssystemen grosser Dimension. Hierfur werden moderne vorkonditionierte Iterationsverfahren (z. B. CG, GMRES, BiCGStab) hergeleitet und die zur Realisierung notwendigen Algorithmen beschrieben. Fur Systeme mit strukturierten Matrizen werden effiziente direkte Losungsverfahren angegeben. Numerische Beispiele fur praktische Problemstellungen illustrieren die Effizienz der vorgestellten Verfahren.

Fur die naherungsweise Losung von Randwertproblemen zweiter Ordnung wird eine einheitliche Theorie der Finiten Elemente Methode und der Randelementmethode prasentiert. Neben der Stabilitats- und Fehleranalysis wird vor allem auf effiziente Losungsverfahren eingegangen. Fur die Diskretisierung der auftretenden Randintegraloperatoren werden schnelle Randelementmethoden (Wavelets, Multipol, algebraische Techniken) mit der Darstellung durch partielle Integration verknupft. Durch die Kopplung von FEM und BEM mittels Gebietszerlegungsmethoden konnen gekoppelte Randwertprobleme in komplexen Strukturen behandelt werden. Numerische Beispiele illustrieren die theoretischen Aussagen.

Domain decomposition methods are a well established tool for an efficient numerical solution of partial differential equations, in particular for the coupling of different model equations and of different discretization methods. Based on the approximate solution of local boundary value problems either by finite or boundary element methods, the global problem is reduced to an operator equation on the skeleton of the domain decomposition. Different variational formulations then lead to hybrid domain decomposition methods.