Optimal Shape Design For Elliptic Systems

The study of optimal shape design can be arrived at by asking the following question: "What is the best shape for a physical system?" This book is an applications-oriented study of such physical systems; in particular, those which can be described by an elliptic partial differential equation and where the shape is found by the minimum of a single criterion function. There are many problems of this type in high-technology industries. In fact, most numerical simulations of physical systems are solved not to gain better understanding of the phenomena but to obtain better control and design. Problems of this type are described in Chapter 2. Traditionally, optimal shape design has been treated as a branch of the calculus of variations and more specifically of optimal control. This subject interfaces with no less than four fields: optimization, optimal control, partial differential equations (PDEs), and their numerical solutions-this is the most difficult aspect of the subject. Each of these fields is reviewed briefly: PDEs (Chapter 1), optimization (Chapter 4), optimal control (Chapter 5), and numerical methods (Chapters 1 and 4).

The present monograph is intended to provide a comprehensive and accessible introduction to the optimization of elliptic systems. This area of mathematical research, which has many important applications in science and technology. has experienced an impressive development during the past two decades. There are already many good textbooks dealing with various aspects of optimal design problems. In this regard, we refer to the works of Pironneau [1984], Haslinger and Neittaanmaki [1988], [1996], Sokolowski and Zolksio [1992], Litvinov [2000], Allaire [2001], Mohammadi and Pironneau [2001], Delfour and Zolksio [2001], and Makinen and Haslinger [2003]. Already Lions [I9681 devoted a major part of his classical monograph on the optimal control of partial differential equations to the optimization of elliptic systems. Let us also mention that even the very first known problem of the calculus of variations, the brachistochrone studied by Bernoulli back in 1696. is in fact a shape optimization problem. The natural richness of this mathematical research subject, as well as the extremely large field of possible applications, has created the unusual situation that although many important results and methods have already been est- lished, there are still pressing unsolved questions. In this monograph, we aim to address some of these open problems; as a consequence, there is only a minor overlap with the textbooks already existing in the field.

Abstract: "The fictitious domain method is used in the numerical solution of partial differential equations in exterior domains or in order to apply finite differences to systems defined in domains with a complicated geometry. The principle of this approach is very useful in problems with unknown or variable domains. Taking into account certain exact controllability properties for linear or nonlinear elliptic equations, we develop an approximation method for optimal design problems by distributed control problems in a fixed domain."

Optimal Shape Design is concerned with the optimization of some performance criterion dependent (besides the constraints of the problem) on the "shape" of some region. The main topics covered are: the optimal design of a geometrical object, for instance a wing, moving in a fluid; the optimal shape of a region (a harbor), given suitable constraints on the size of the entrance to the harbor, subject to incoming waves; the optimal design of some electrical device subject to constraints on the performance. The aim is to show that Optimal Shape Design, besides its interesting industrial applications, possesses nontrivial mathematical aspects. The main theoretical tools developed here are the homogenization method and domain variations in PDE. The style is mathematically rigorous, but specifically oriented towards applications, and it is intended for both pure and applied mathematicians. The reader is required to know classical PDE theory and basic functional analysis.

This volume presents developments and advances in modelling passive and active control systems governed by partial differential equations. It emphasizes shape analysis, optimal shape design, controllability, nonlinear boundary control, and stabilization. The authors include essential data on exact boundary controllability of thermoelastic plates with variable transmission coefficients.

This is an exposition of the theory, techniques, and the basic formulation of structural optimization problems. The author considers applications of design optimization criteria involving strength, rigidity, stability and weight. Analytic and numerical techniques are introduced for research in optimal shapes and internal configurations of deformable bodies and structures. Problems of the optimal design of beams, systems of rods, plates and shells, are studied in detail. With regard to applications, this work is oriented towards solutions of real problems, such as reduction of the volume or weight of the material, and improvement of mechanical properties of structures. This book is written for readers specializing in applied mechanics, applied mathematics, and numerical analysis."

This book analyzes the impact of scientific computing in science and society over the coming decades. It presents advanced methods that can provide new possibilities to solve scientific problems and study important phenomena in society. The chapters cover Scientific computing as the third paradigm of science as well as the impact of scientific computing on natural sciences, environmental science, economics, social science, humanistic science, medicine, and engineering. Moreover, the book investigates scientific computing in high performance computing, quantum computing, and artificial intelligence environment and what it will be like in the 2030s and 2040s.

The European Consortium for Mathematics in Industry (ECMI) was founded, largely due to the driving energy of Michiel Hazewinkel on the 14th April, 1986 in Neustadt-Mussbach in West Germany. The founder signatories were A. Bensoussan (INRIA, Paris), A. Fasano (University of Florence), M. Hazewinkel (CWI, Amsterdam), M. Heilio (Lappeenranta University, Finland), F. Hodnett (University of Limerick, Ireland), H. Martens (Norwegian Institute of Technology, Trondheim), S. McKee (University of Strathclyde, Scotland), H. NeURzert (University of Kaiserslautern, Germany), D. Sundstrom (The Swedish Institute of Applied Mathematics, Stockholm), A. Tayler (University of Oxford, England) and Hj. Wacker (University of Linz, Austria). The European Consortium for Mathematics in Industry is dedicated to: (a) promote the use of mathematical models in Industry (b) educate industrial mathematicians to meet the growing demand for such experts (c) operate on a European scale. ECMI is still a young organisation but its membership is growing fast. Although it has still to persuade more industrialists to join, ECMI certainly operates on a European scale and a flourishing postgraduate programme with student exchange has been underway for some time. It is perhaps fitting that the first open meeting of ECMI was held at the University of Strathclyde in Glasgow. Glasgow is and was the industrial capital of Scotland and was, and arguably still is, Britain's second city after London; when this volume appears it will have rightly donned the mantle of the cultural capital of Europe.