Computational Kinematics ’95


Book Description

The aim of this book is to provide an account of the state of the art in Com putational Kinematics. We understand here under this term that branch of kinematics research involving intensive computations not only of the nu merical type, but also of symbolic as well as geometric nature. Research in kinematics over the last decade has been remarkably ori ented towards the computational aspects of kinematics problems. In fact, this work has been prompted by the need to answer fundamental questions such as the number of solutions, whether real or complex, that a given problem can admit as well as computational algorithms to support geo metric analysis. Problems of the first kind occur frequently in the analysis and synthesis of kinematic chains, when fine displacements are considered. The associated models, that are derived from kinematic relations known as closure equations, lead to systems of nonlinear algebraic equations in the variables or parameters sought. The algebraic equations at hand can take the form of multivariate polynomials or may involve trigonometric functions of unknown angles.




Computational Kinematics


Book Description

The aim of this book is to provide an account of the state of the art in Com putational Kinematics. We understand here under this term ,that branch of kinematics research involving intensive computations not only of the numer ical type, but also of a symbolic nature. Research in kinematics over the last decade has been remarkably ori ented towards the computational aspects of kinematics problems. In fact, this work has been prompted by the need to answer fundamental question s such as the number of solutions, whether real or complex, that a given problem can admit. Problems of this kind occur frequently in the analysis and synthesis of kinematic chains, when finite displacements are considered. The associated models, that are derived from kinematic relations known as closure equations, lead to systems of nonlinear algebraic equations in the variables or parameters sought. What we mean by algebraic equations here is equations whereby the unknowns are numbers, as opposed to differen tial equations, where the unknowns are functions. The algebraic equations at hand can take on the form of multivariate polynomials or may involve trigonometric functions of unknown angles. Because of the nonlinear nature of the underlying kinematic models, purely numerical methods turn out to be too restrictive, for they involve iterative procedures whose convergence cannot, in general, be guaranteed. Additionally, when these methods converge, they do so to only isolated solu tions, and the question as to the number of solutions to expect still remains.




Direct Methods for Solving the Boltzmann Equation and Study of Nonequilibrium Flows


Book Description

This book is concerned with the methods of solving the nonlinear Boltz mann equation and of investigating its possibilities for describing some aerodynamic and physical problems. This monograph is a sequel to the book 'Numerical direct solutions of the kinetic Boltzmann equation' (in Russian) which was written with F. G. Tcheremissine and published by the Computing Center of the Russian Academy of Sciences some years ago. The main purposes of these two books are almost similar, namely, the study of nonequilibrium gas flows on the basis of direct integration of the kinetic equations. Nevertheless, there are some new aspects in the way this topic is treated in the present monograph. In particular, attention is paid to the advantages of the Boltzmann equation as a tool for considering nonequi librium, nonlinear processes. New fields of application of the Boltzmann equation are also described. Solutions of some problems are obtained with higher accuracy. Numerical procedures, such as parallel computing, are in vestigated for the first time. The structure and the contents of the present book have some com mon features with the monograph mentioned above, although there are new issues concerning the mathematical apparatus developed so that the Boltzmann equation can be applied for new physical problems. Because of this some chapters have been rewritten and checked again and some new chapters have been added.




Nonlinear and Stochastic Dynamics of Compliant Offshore Structures


Book Description

The purpose of this monograph is to show how a compliant offshore structure in an ocean environment can be modeled in two and three di mensions. The monograph is divided into five parts. Chapter 1 provides the engineering motivation for this work, that is, offshore structures. These are very complex structures used for a variety of applications. It is possible to use beam models to initially study their dynamics. Chapter 2 is a review of variational methods, and thus includes the topics: princi ple of virtual work, D'Alembert's principle, Lagrange's equation, Hamil ton's principle, and the extended Hamilton's principle. These methods are used to derive the equations of motion throughout this monograph. Chapter 3 is a review of existing transverse beam models. They are the Euler-Bernoulli, Rayleigh, shear and Timoshenko models. The equa tions of motion are derived and solved analytically using the extended Hamilton's principle, as outlined in Chapter 2. For engineering purposes, the natural frequencies of the beam models are presented graphically as functions of normalized wave number and geometrical and physical pa rameters. Beam models are useful as representations of complex struc tures. In Chapter 4, a fluid force that is representative of those that act on offshore structures is formulated. The environmental load due to ocean current and random waves is obtained using Morison's equa tion. The random waves are formulated using the Pierson-Moskowitz spectrum with the Airy linear wave theory.




IUTAM Symposium on Chaotic Dynamics and Control of Systems and Processes in Mechanics


Book Description

The interest of the applied mechanics community in chaotic dynamics of engineering systems has exploded in the last fifteen years, although research activity on nonlinear dynamical problems in mechanics started well before the end of the Eighties. It developed first within the general context of the classical theory of nonlinear oscillations, or nonlinear vibrations, and of the relevant engineering applications. This was an extremely fertile field in terms of formulation of mechanical and mathematical models, of development of powerful analytical techniques, and of understanding of a number of basic nonlinear phenomena. At about the same time, meaningful theoretical results highlighting new solution methods and new or complex phenomena in the dynamics of deterministic systems were obtained within dynamical systems theory by means of sophisticated geometrical and computational techniques. In recent years, careful experimental studies have been made to establish the actual occurrence and observability of the predicted dynamic phenomena, as it is vitally needed in all engineering fields. Complex dynamics have been shown to characterize the behaviour of a great number of nonlinear mechanical systems, ranging from aerospace engineering applications to naval applications, mechanical engineering, structural engineering, robotics and biomechanics, and other areas. The International Union of Theoretical and Applied Mechanics grasped the importance of such complex phenomena in the Eighties, when the first IUTAM Symposium devoted to the general topic of nonlinear and chaotic dynamics in applied mechanics and engineering was held in Stuttgart (1989).




Applied High-Speed Plate Penetration Dynamics


Book Description

High-speed impact dynamics is of interest in the fundamental sciences, e.g., astrophysics and space sciences, and has a number of important applications in military technologies, homeland security and engineering. When compared with experiments or numerical simulations, analytical approaches in impact mechanics only seldom yield useful results. However, when successful, analytical approaches allow us to determine general laws that are not only important in themselves but also serve as benchmarks for subsequent numerical simulations and experiments. The main goal of this monograph is to demonstrate the potential and effectiveness of analytical methods in applied high-speed penetration mechanics for two classes of problem. The first class of problem is shape optimization of impactors penetrating into ductile, concrete and some composite media. The second class of problem comprises investigation of ballistic properties and optimization of multi-layered shields, including spaced and two-component ceramic shields. Despite the massive use of mathematical techniques, the obtained results have a clear engineering meaning and are presented in an easy-to-use form. One of the chapters is devoted solely to some common approximate models, and this is the first time that a comprehensive description of the localized impactor/medium interaction approach is given. In the monograph the authors present systematically their theoretical results in the field of high-speed impact dynamics obtained during the last decade which only partially appeared in scientific journals and conferences proceedings.




IUTAM Symposium on Mechanical Waves for Composite Structures Characterization


Book Description

This book is a collection of selected reviewed papers that were presented at the International Union of Theoretical and Applied Mechanics Symposium "Mechanical waves for composite structures characterization". The Symposium took place June 14-17, 2000 in Chania, Crete, Greece. As is customary, IUTAM Symposia Proceedings are published in the series "Solid Mechanics and Its Applications" by Kluwer Academic Publishers. I am indebted to Professor G. M. L. Gladwell who is the series editor. I would also like to take this opportunity to express my sincere gratitude to Professor M. A. Hayes the Secretary General of the International Union of Theoretical and Applied Mechanics and a member ofthe Symposium's Scientific Committee. His constant encouragement and support made the Symposium not only possible but also successful. To the success also contributed all the members of the Symposium's Scientific Committee which I had the honor to chair. I express my appreciation to each one of them who are: Professor J. D. Achenbach (Northwestern University, Evanston, Illinois, USA), Professor M. A. Hayes (University College, Dublin, Ireland), Professor K. J. Langenberg (University of Kassel, Germany), Professor A. K. Mal (University of California, Los Angeles, USA), Professor X. Markenscoff (University of California, San Diego, USA), Professor S. Nair (Illinois Institute of Technology, Chicago, USA), Professor R. W. Ogden (University of Glasgow, UK), Professor G.




IUTAM Symposium on Mechanical and Electromagnetic Waves in Structured Media


Book Description

The IUTAM Symposium on Mechanical and Electromagnetic Waves in Structured Media took place at the University of Sydney from January 18- 22, 1999. It brought together leading researchers from eleven countries for a week-long meeting, with the aim of providing cross-links between the com- nities studying related problems involving elastic and electromagnetic waves in structured materials. After the meeting, participants were invited to submit articles based on their presentations, which were refereed and assembled to constitute these Proceedings. The topics covered here represent areas at the forefront of research intoelastic and electromagnetic waves. They include effect of nonlinearity, diffusion and multiple scattering on waves, as well as asymptotic and numerical techniques. Composite materials are discussed in depth, with example systems ranging fromdusty plasmas to a magneto-elastic microstructured system. Also included are studies of homogenisation, that field which seeks to determine equivalent homogeneous systems which can give equivalent wave properties to structured materials, and inverse problems, in which waves are used as a probe to infer structural details concerning scattering systems. There are also strong groups of papers on the localization of waves by random systems, and photonic and phononic band gap materials. These are being developed by analogue with semiconductors for electrons, and hold out the promise of enabling designers to control the propagation of waves through materials in novel ways. We would like to thank the other members of the Scientific Committee (A.




IUTAM Symposium on Mesoscopic Dynamics of Fracture Process and Materials Strength


Book Description

This volume contains the papers presented at the IUT AM Symposium of "Mesoscopic Dynamics of Fracture Process and Materials Strength", held in July 2003, at the Hotel Osaka Sun Palace, Osaka, Japan. The Symposium was proposed in 2001, aiming at organizing concentrated discussions on current understanding of fracture process and inhomogeneous deformation governing the materials strength with emphasis on the mesoscopic dynamics associated with evolutional mechanical behaviour under micro/macro mutual interaction. The decision of the General Assembly of International Union of Theoretical and Applied Mechanics (IUT AM) to accept our proposal was well-timed and attracted attention. Driven by the development of new theoretical and computational techniques, various novel challenges to investigate the mesoscopic dynamics have been actively done recently, including large-scaled 3D atomistic simulations, discrete dislocation dynamics and other micro/mesoscopic computational analyses. The Symposium attracted sixty-six participants from eight countries, and forty two papers were presented. The presentations comprised a wide variety of fundamental subjects of physics, mechanical models, computational strategies as well as engineering applications. Among the subjects, discussed are (a) dislocation patterning, (b) crystal plasticity, (c) characteristic fracture of amorphous/nanocrystal, (d) nano-indentation, (e) ductile-brittle transition, (f) ab-initio calculation, (g) computational methodology for multi-scale analysis and others.




Functional Analysis


Book Description

This book started its life as a series of lectures given by the second author from the 1970's onwards to students in their third and fourth years in the Department of Mathematics at the Rostov State University. For these lectures there was also an audience of engineers and applied mechanicists who wished to understand the functional analysis used in contemporary research in their fields. These people were not so much interested in functional analysis itself as in its applications; they did not want to be told about functional analysis in its most abstract form, but wanted a guided tour through those parts of the analysis needed for their applications. The lecture notes evolved over the years as the first author started to make more formal typewritten versions incorporating new material. About 1990 the first author prepared an English version and submitted it to Kluwer Academic Publishers for inclusion in the series Solid Mechanics and its Applications. At that stage the notes were divided into three long chapters covering linear and nonlinear analysis. As Series Editor, the third author started to edit them.