Magnetic Bearings are bearings where the suspension forces are generated magnetically without any contact. The advantages to modern machinery are obvious: no mechanical wear, no lubrication, potential for high rotor speed, accuracy, and high dynamic performance, new constructional solutions to a classical problem in machine dynamics. The realization of such bearings is in rapid progress. Examples for application areas are turbomachinery, centrifuges, vacuum techniques, machine tool spindles, chemical industry, medical devices, robotics, high speed drives, spacecraft equipment, con tactless actuators, vibration isolation. The Symposium is demonstrating the current state of the art in this developing field of mechatronics, showing actual research efforts, reporting on applications in the various areas, and discussing open questions. The main purpose of the Symposium has been to establish a common information basis for people working on magnetic bearings. It will point to promising areas, and it will help to facilitate decisions on research and development projects, and on investments for applications.

The IUTAM Symposium on "Discrete Structural Optimization" was devoted to discuss optimization problems for which design va riables may not be sought among continuous sets. Optimum sizing from lists of available profiles, segmentation; as well as allocation and number of supports, sensors or actuators, are good exam ples of such problems for which design variables may be chosen only from finite sets. The above problems are having not only important practical applications. They are also inspiring scienti fic research in the field of discrete applied mathematics. Among them are controlled enumeration methods, subgradient approach, genetic programming, multicriteria optimization, neural nets etc. Along with its tradition of promoting and supporting new im portant fields of research in mechanics and its application, General Assembly of IUTAM decided in 1990 to support the Sumposium. It is worthy to note that this is the second IUTAM Symposium on structural optimization, organized in Poland. The first one was held in Warsaw twenty years ago and was organized by Profe ssors Sawczuk and Mroz. It was devoted mostly to problems with continuous design variables. The Symposium which gathered 40 participants from 12 coun tries was sponsored by several institutions listed below. However support by IUTAM should be specially appreciated. It helped se veral scientists to contribute to the Symposium which other way wouldn't attend the meeting."

Dynamics of multibody systems is of great importance in the fields of robotics, biomechanics, spacecraft control, road and rail vehicle design, and dynamics of machinery. Many research problems have been solved and a considerable number of computer codes based on multibody formalisms is now available. With the present book it is intended to collect software systems for multibody system dynamics which are well established and have found acceptance in the users community. The Handbook will aid the reader in selecting the software system which is most appropriate to his needs. Altogether 17 research groups contributed to the Handbook. A compact summary of important capabilities of these software systems is presented in tabular form. All authors dealt with two typical test examples, a planar mechanism and a spatial robot. Thus, it is very easy to compare the results and to identify more clearly the advantages of one or the other formalism.

This volume collects my shorter articles on the history of mechanics, some already published in various places, some revised from earlier papers, and some never published before. All of them began as lectures, and here they are printed as such, little changed from the last times I read them out to an audience. While the several articles concern different aspects of mechanics, overlap and even some repetition could not be avoided, since mechanics is one great science, and the same original oftentimes served more than one end in its growth. My three major historical treatises, which were published in Volumes (II) 11, 2 12, and 13 of L. Euleri Opera Omnia, are not included. To simplify the printing I have also mostly omitted detailed reference to sources discussed more fully in those treatises, but of course I have added to the texts of the lectures citations of other sources, some notes in answer to questions a reader might ask, and biblio graphical notes at the end of each. I am grateful to the U.S. National Science Foundation for its support of this work through a grant to The Johns Hopkins University."

The Colloquium on Creep in Structures was organized as part of the activities of the International Union on Theoretical and Applied Mecha nies. It was supported financiaHy by IUTAM, as weH as by the National Science Foundation, Washington, D. C., U. S. A. The Scientific Commit tee charged with the work of organization consisted of the foHowing persons: NICHOLAS J. HOFF, Stanford University, Stanford, California, Chair man FOLKE K. G. ODQVIST, Royal Institute of Technology, Stockholm, Sweden, Vice-Chairman R. MAZET, Office National d'Etudes et de Recherehes Aeronautiques, Chatillon-sous-Bagneux, France Y. N. RABOTNOV, Academy of Sciences, Novosibirsk, U. S. S. R. SHUJI TAIRA, Kyoto University, Kyoto, Japan. The details of the organization of the sessions were entrusted to the Local Committee consisting of the following persons: MAX ANLIKER W. H. HORToN K. BINFORD B. LEMPRIERE C.C.CHAO L. NICKEL W. G. FLUGGE In order to insure good discussion and, in general, a broad exchange of ideas among the participants in the meeting, the number of persons invited to attend was kept to a minimum. Participants not living in the Stanford area were housed in Donner House of Stern Hall on the Stanford campus, and were served meals in the dining room of Donner House. The speakers and observers started to arrive on July 9 and the last ones left on July 18."

This technical book considers the application side of LDA techniques. Starting from the basic theories that are crucial for each LDA user, the main subject of the book is focused on diverse application methods. In details, it deals with universal methodical techniques that have been mostly developed in the last 15 years. The book thus gives for the first time an application reference for LDA users in improving the optical conditions and enhancing the measurement accuracies. It also provides the guidelines for simplifying the measurements and correcting measurement errors as well as for clarifying the application limits and extending the application areas of LDA techniques. Beside the treatments of some traditional optical and flow mechanical features influencing the measurement accuracies, the book shows a broad spectrum of LDA application methods in the manner of measuring the flow turbulence, resolving the secondary flow structures, and quantifying the optical aberrations at measurements of internal flows etc.. Thus, it also supports the further developments of both the hard- and software of LDA instrumentations.

As the shift from the Metal Age progresses, materials engineers and materials scientists seek new analytical and design methods to create stronger and more reliable materials. Based on extensive research and developmental work done at the author s multi-disciplinary material laboratory, this graduate-level and professional reference addresses the relationship between fracture mechanisms (macroscale) and the microscopic, with the goal of explaining macroscopic fracture behavior based on a microscopic fracture mechanism. A careful fusion of mechanics and materials science, this text and monograph systematically considers an array of materials, from metals through ceramics and polymers, and demonstrates lab-tested strategies to develop desirable high-temperature materials for technological applications."

Thin shells are three-dimensional structures with a dimension (the thickness) small with respect to the two others.Such thin structures are widely used in automobileandaviation industries,or in civil engineering, because they provide animportantsti?ness, due to theircurvature,with a small weight. Fig. 0.1. Airbus A380 Fig. 0.2. Hemispherical roof (Marseille, France) One ofthechallenges is often to reduce the weight (andconsequently the thickness)oftheshells, preservingtheirsti?ness.So that it is essential to have 1 accuratemodelsforthinandevenverythinshells ,andtobeabletocomputethe displacements resultingfromagivenloading.In particular, singularities leading to fractures in some cases must be absolutely predicted a priori and ofcourse avoided (see Fig.0.3 forexample). Since the pioneeringmodels of Novozhilov-Donnell [81] and Koiter [65][66], numerous works havebeen devoted to establish linear and non linear elastic shell model usingdirect orsurfacic approaches [18][25][100]. More recently, the asymptoticmethods [87] havebeen used, to try tojustify rigorously, fromthe three-dimensional equations, the shell models obtained by direct approaches - lying onapriori assumption, andto construct new models [54][55]. This way, 1 Very thin shells are present in certain domains of industry, as plastic ?lms for pa- aging or for electronics, streched sails, or even very thin metal sheets obtained by drawing. E. Sanchez-Palencia et al.: Singular Problems in Shell Theory, LNACM 54, pp. 1-11.

The Eurotherm Committee has chosen Thermal Management of Electronic Systems as the subject of its 29th Seminar, at Delft University of Technology, the Netherlands, 14-16 June 1993. This volume constitutes the proceedings of the Seminar. Thermal Management is but one of the several critical topics in the design of electronic systems. However, as a result of the combined effects of increasing heat fluxes, miniaturisation and the striving for zero defects, preferably in less time and at a lower cost than before, thermal management has become an increasingly tough challenge. Therefore, it is being increasingly recognised that cooling requirements could eventually hamper the technical progress in miniaturisation. It might be argued that we are on the verge of a revolution in thermal management techniques. Previously, a packaging engineer had no way of predicting the tempera tures of critical electronic parts with the required accuracy. He or she* had to rely on full-scale experiments, doubtful design rules, or worst-case estimates. This situation is going to be changed in the foreseeable future. User-friendly software tools, the acquisition and integrity of input and output data, the badly needed training mea sures, the introduction into a concurrent engineering environment: all these items will exert a heavy toll on the flexibility of the electronics industries. Fortunately, this situation is being realised at the appropriate management levels, and the interest in this seminar and the pre-conference tutorials testifies to this assertion.

Metal Oxide Nanoparticles in Organic Solvents discusses recent advances in the chemistry involved for the controlled synthesis and assembly of metal oxide nanoparticles, the characterizations required by such nanoobjects, and their size and shape depending properties. In the last few years, a valuable alternative to the well-known aqueous sol-gel processes was developed in the form of nonaqueous solution routes. Metal Oxide Nanoparticles in Organic Solvents reviews and compares surfactant- and solvent-controlled routes, as well as providing an overview of techniques for the characterization of metal oxide nanoparticles, crystallization pathways, the physical properties of metal oxide nanoparticles, their applications in diverse fields of technology, and their assembly into larger nano- and mesostructures. Researchers and postgraduates in the fields of nanomaterials and sol-gel chemistry will appreciate this book's informative approach to chemical formation mechanisms in relation to metal oxides.

The articles in this book present advanced soft methods related to genetic and evolutionary algorithms, immune systems, formulation of deterministic neural networks and Bayesian NN. Many attention is paid to hybrid systems for inverse analysis fusing soft methods and the finite element method. Numerical efficiency of these soft methods is illustrated on the analysis and design of complex engineering structures.

PREFACE The theory of differential-operator equations has been described in various monographs, but the initial physical problem which leads to these equations is often hidden. When the physical problem is studied, the mathematical proofs are either not given or are quickly explained. In this book, we give a systematic treatment of the partial differential equations which arise in elastostatic problems. In particular, we study problems which are obtained from asymptotic expansion with two scales. Here the methods of operator pencils and differential-operator equations are used. This book is intended for scientists and graduate students in Functional Analy sis, Differential Equations, Equations of Mathematical Physics, and related topics. It would undoubtedly be very useful for mechanics and theoretical physicists. We would like to thank Professors S. Yakubov and S. Kamin for helpfull dis cussions of some parts of the book. The work on the book was also partially supported by the European Community Program RTN-HPRN-CT-2002-00274. xiii INTRODUCTION In first two sections of the introduction, a classical mathematical problem will be exposed: the Laplace problem. The domain of definition will be, on the first time, an infinite strip and on the second time, a sector. To solve this problem, a well known separation of variables method will be used. In this way, the structure of the solution can be explicitly found. For more details about the separation of variables method exposed in this part, the reader can refer to, for example, the book by D. Leguillon and E. Sanchez-Palencia LS]."

This 2003 book relates the complete set of strength characteristics of constituent atoms to their electronic structures. These relationships require knowledge of both the chemistry and physics of materials. The book uses both classical and quantum mechanics, since both are needed to describe these properties, and begins with short reviews of each. Following these reviews, the three major branches of the strength of materials are given their own sections. They are: the elastic stiffnesses; the plastic responses; and the nature of fracture. This work will be of great value to academic and industrial research workers in the sciences of metallurgy, ceramics, microelectronics and polymers. It will also serve well as a supplementary text for the teaching of solid mechanics.

This text provides an introduction, at the level of an advanced student in engineering or physics, to the field of nanomechanics and nanomechanical devices. It provides a unified discussion of solid mechanics, transducer applications, and sources of noise and nonlinearity in such devices. Demonstrated applications of these devices, as well as an introduction to fabrication techniques, are also discussed. The text concludes with an overview of future technologies, including the potential use of carbon nanotubes and other molecular assemblies.

This monograph covers phenomena of deformation and machining of granular media: macroscopic particles of different size, shape, and surface properties which typically exhibit behavior similar to fluids, as well as the behavior of solids under deformation. The book analyses the behavior of granular media in soils, rocks and stones, metals and various synthetic materials, presenting a theoretical description, applications and understanding of basic phenomena in granular matter.

Since the original publication of Noncontact Atomic Force Microscopy in 2002, the noncontact atomic force microscope (NC-AFM) has achieved remarkable progress. This second treatment deals with the following outstanding recent results obtained with atomic resolution since then: force spectroscopy and mapping with atomic resolution; tuning fork; atomic manipulation; magnetic exchange force microscopy; atomic and molecular imaging in liquids; and other new technologies. These results and technologies are now helping evolve NC-AFM toward practical tools for characterization and manipulation of individual atoms/molecules and nanostructures with atomic/subatomic resolution. Therefore, the book exemplifies how NC-AFM has become a crucial tool for the expanding fields of nanoscience and nanotechnology.

The International Union of Theoretical and Applied Mechanics (IUTAM) decided in 1992 to sponsor the fourth Symposium on Laminar-Turbulent Transition, Sendai/Japan, 1994. The objectives of the present Symposium were to deepen the fundamental knowledge of stability and laminar turbulent transition in three-dimensional and compressible flows and to contribute to recent developing technologies in the field. This Symposium followed the three previous IUTAM-Symposia (Stuttgart 1979, Novosibirsk 1984 and Toulouse 1989). The Scientific Committee selected two keynote lectures and 62 technical papers. The Symposium was held on the 5th to 9th of September, 1994, at the Sendai International Center in Sendai. The participants were 82 scientists from 10 countries. The keynote lectures have critically reviewed recent development of researches concerning the laminar-to-turbulent transition phenomena from the fundamental and the application aspects. Many papers presented were concerned about the detailed mechanism of the boundary layer transition (receptivity, secondary instability, turbulent spot and bypass transition). Particular emphasis was further placed on the transition of three-dimensional boundary layers on rotation systems and on swept wings. Attention was also given to compressible hypersonic flows."

The problems of transient interaction of deformable bodies with surrounding media are of great practical and theoretical importance. When solving the problems of this kind, the main difficulty is in the necessity to integrate jointly the system of equations which describe motion of the body and the system of equations which describe motion of the medium under the boundary conditions predetermined at the unknown (movable) curvilinear interfaces. At that, the position of these interfaces should be determined as part of the solution process. That is why, the known exact solutions in this area of mechanics of continuum have been derived mainly for the cases of idealized rigid bodies. Different aspects of the problems of transient interaction of bodies and structures with continuum (derivation of the efficient mathematical mod els for the phenomenon, development of the theoretical and experimental methods to be used for study of the transient problems of mechanics, etc.) were considered in the books by S.U. Galiev, A.N. Guz, V.D. Kubenko, V.B. Poruchikov, L.L Slepyan, A.S. Volmir, and Yu.S. Yakovlev. The results presented by these authors make interest when solving a great variety of problems and show a necessity of joint usage of the results obtained in differ ent areas: aerohydrodynamics, theory of elasticity and plasticity, mechanics of soils, theory of shells and plates, applied and computational mathemat ics, etc.

This monograph is intended to provide a snapshot of the status and opportunities for advan cement in the technologies of dynamics and control oflarge flexible spacecraft structures. It is a reflection ofthe serious dialog and assessments going on all over the world, across a wide variety of scientific and technical disciplines, as we contemplate the next major milestone in mankind's romance with space: the transition from exploration and experimentation to commercial and defense exploitation. This exploitation is already in full swing in the space communications area. Both military and civilian objectives are being pursued with increasingly more sophisticated systems such as large antenna reflectors with active shape control. Both the NATO and Warsaw pact alliances are pursuing permanent space stations in orbit: large structural systems whose development calls for in-situ fabrication and/or assembly and whose operation will demand innovations in controls technology. The last ten years have witnessed a fairly brisk research activity in the dynamics and control oflarge space structures in orderto establish a technology base forthe development of advanced spacecraft systems envisioned for the future. They have spanned a wide spectrum of activity from fundamental methods development to systems concept studies and laboratory experimentation and demonstrations. Some flight experiments have also been conducted for various purposes such as the characterization of the space enviroment, durability of materials and devices in that environment, assembly and repair operations, and the dynamic behavior of flexible structures. It is this last area that has prompted this monogram."

The authors systematically describe the general principles of Kolsky bars, or split Hopkinson bars, which are widely used for obtaining dynamic material properties. Modifications are introduced for obtaining reliable data. Specific experiment design guidelines are provided to subject the specimen to desired testing conditions.

Detailed Kolsky-bar examples are given for different classes of materials (brittle, ductile, soft, etc) and for different loading conditions (tension, torsion, triaxial, high/low temperatures, intermediate strain rate, etc). The Kolsky bars used for dynamic structural characterization are briefly introduced. A collection of dynamic properties of various materials under various testing conditions is included which may serve as a reference database.

This book assists both beginners and experienced professionals in characterizing high-rate material response with high quality and consistency. Readers who may benefit from this work include university students, instructors, R & D professionals, and scholars/engineers in solid mechanics, aerospace, civil and mechanical engineering, as well as materials science and engineering.

The general objective of the Tenth Canadian Fracture Conference was to respond to progress in the engineering sciences - in particular with r- pect to rapidly developing new trends in the theory and methodology of researcr and designing - and to the resulting needs of practical engineering in the specific field of fracture mechanics and related areas of engineering mechanics. The basic underlying issue is the theory and practice of physical analytical and iconic (reduced) modelling of the actually involved physical processes and of the responses of physical bodies and systems to actual energy flow - a problem which is becoming dominant in all fields of the natural sciences. Accordingly, the theme of the CFCIO was "Modelling Problems in Crack Tip Mechanics," a well defined and limited subject, the scope of treatment of which can be as deep and as comprehensive as an in volved researcher wishes it to be."

The aim of the present book is the formulation, mathematical study and numerical treatment of static and dynamic problems in mechanics and engineering sciences involving nonconvex and nonsmooth energy functions, or nonmonotone and multivalued stress-strain laws. Such problems lead to a new type of variational forms, the hemivariational inequalities, which also lead to multivalued differential or integral equations. Innovative numerical methods are presented for the treament of realistic engineering problems. This book is the first to deal with variational theory of engineering problems involving nonmonotone multivalue realations, their mechanical foundation, their mathematical study (existence and certain approximation results) and the corresponding eigenvalue and optimal control problems. All the numerical applications give innovative answers to as yet unsolved or partially solved engineering problems, e.g. the adhesive contact in cracks, the delamination problem, the sawtooth stress-strain laws in composites, the shear connectors in composite beams, the semirigid connections in steel structures, the adhesive grasping in robotics, etc. The book closes with the consideration of hemivariational inequalities for fractal type geometries and with the neural network approach to the numerical treatment of hemivariational inequalities.

Polymer composites were introduced for the aerospace industry as light, strong, stiff materials, and adopted by the construction and automobile industries, among others. Meanwhile, composite materials have been introduced to fulfill the uses that these conventional materials could not, such as in extreme environments. The research for new composites includes not only new polymer systems, but metals, ceramics and intermetallic systems as well. This volume contains a selection of recent work by leading researchers in micromechanics on the topics of prediction of overall properties of elastic, perfectly bonded systems, problems associated with inelastic deformation of the phase, debonding at interfaces and growth of distributed damage. Many familiar aspects of mechanical behavior, such as fatigue, fracture, strength and buckling, etc. have been reexamined and adapted for these new systems.

Here for the first time in one book is a comprehensive and systematic approach to the dynamic modeling and control of biped locomotion robots. A survey is included of various approaches to the control of biped robots, and a new approach to the control of biped systems based on a complete dynamic model is presented in detail. The stability of complete biped system is presented for the first time as a highly nonlinear dynamic system. Also included is new software for the synthesis of a dynamically stable walk for arbitrary biped systems, presented here for the first time. A survey of various realizations of biped systems and numerous numerical examples are given. The reader is given a deep insight into the entire area of biped locomotion. The book covers all relevant approaches to the subject and gives the most complete account to date of dynamic modeling, control and realizations of biped systems.

During the last two decades more and more universities offer courses on modern structural reliability theory. A course on structural reliability theory is now a natural part of the curri culum for mechanical and structural engineering students. As a result of this, a number of textbooks have been published in this decade. In PlOst of these books it is shown how the reliability of single structural members can be evaluated in a rational way. The methods used are usually so-called level 2 methods, i. e. methods involving certain approximate iter ative calculations to obtain an approximate value of the probability of failure of the struc tural members. In these methods the joint probability distribution of relevant variables (re sistance variables, loads, etc. ) is simplified and the failure criteria are idealized in such a way that the reliability calculations can be performed without an unreasonable amount of work. In spite of the approximations and idealizations made it is believed that a rational treatment of uncertainties in structural engineering can be obtained by level 2 methods. Usually, in sufficient data are at hand to make a more advanced estimate of the reliability of a struc tural member. It has been recognized for many years that a fully satisfactory estimate of the reliability of a structure must be based on a systems approach. In some situations it is sufficient to estimate the reliability of the individual structural members of a structural system."