Dynamics And Control Of Structures

This book addresses problems in structural dynamics and control encountered in applications such as robotics, aerospace structures, earthquake-damage prevention, and active noise suppression. The rapid developments of new technologies and computational power have made it possible to formulate and solve engineering problems that seemed unapproachable only a few years ago. This presentation combines concepts from control engineering (such as system norms and controllability) and structural engineering (such as modal properties and models), thereby revealing new structural properties as well as giving new insight into well-known laws. This book will assist engineers in designing control systems and dealing with the complexities of structural dynamics.

Science is for those who learn; poetry for those who know. —Joseph Roux This book is a continuation of my previous book, Dynamics and Control of Structures [44]. The expanded book includes three additional chapters and an additional appendix: Chapter 3, “Special Models”; Chapter 8, “Modal Actuators and Sensors”; and Chapter 9, “System Identification. ” Other chapters have been significantly revised and supplemented with new topics, including discrete-time models of structures, limited-time and -frequency grammians and reduction, almo- balanced modal models, simultaneous placement of sensors and actuators, and structural damage detection. The appendices have also been updated and expanded. Appendix A consists of thirteen new Matlab programs. Appendix B is a new addition and includes eleven Matlab programs that solve examples from each chapter. In Appendix C model data are given. Several books on structural dynamics and control have been published. Meirovitch’s textbook [108] covers methods of structural dynamics (virtual work, d’Alambert’s principle, Hamilton’s principle, Lagrange’s and Hamilton’s equations, and modal analysis of structures) and control (pole placement methods, LQG design, and modal control). Ewins’s book [33] presents methods of modal testing of structures. Natke’s book [111] on structural identification also contains excellent material on structural dynamics. Fuller, Elliot, and Nelson [40] cover problems of structural active control and structural acoustic control.

This book, intended for people in engineering and fundamental sciences, presents an integrated mathematical methodology for advanced dynamics and control of structures and machines, ranging from the derivation of models up to the control synthesis problem. This point of view is particularly useful as the physical insight and the associated structural properties, related e.g. to the Lagrangian or Hamiltonian framework, can be advantageously utilized. To this end, up to date results in disciplines like continuum mechanics, analytical mechanics, thermodynamics and electrodynamics are presented exploiting the differential geometric properties, with the basic notions of this coordinate-free approach revisited in an own chapter. In order to illustrate the proposed methodologies, several industrial applications, e.g., the derivation of exact solutions for the deformation compensation by shaped actuation in elastic bodies, or the coordination of rigid and flexible joint robots, are discussed.

This book is an outgrowth of several years of teaching and research of the two authors in the field of structural dynamics and control. The content of the book is based on structural dynamics, classical and modern control theory and involves also recent developments that took place with respect to the control of systems with distri buted masses. It is hoped that the book will serve the researcher and the practicing engineer in the areas of ci vi 1, mechanical and aeronautical engineering. It may also be of interest to applied mathematicians and to physicists. There is no question that the book can be used as a reference book for advanced courses in the above mentioned areas. The numerous examples will provide students with the necessary material for exercising themselves and for self studying. Thanks are due to Mrs. Cynthia Jones for preparing patiently and competently the typescript of the book. The services of Mrs. Linda Strouth, Solid Mechanics Division, University of Waterloo, rendered in producing the camera-ready copy of the book with great skill and devotion, are gratefully acknowledged. Special thanks go to Mr. Ir. Ad. C. Plaizier, at Martinus Nijhoff/Dr. W. Junk, who with much understanding and enthusiasm supervised the production of the book as Publisher. May the readers of it enjoy it, and may they have the fee ling of having gained something in turning to it and using it.

Dynamics of Smart Structures is a practical, concise and integrated text that provides an introduction to the fundamental principles of a field that has evolved over the recent years into an independent and identifiable subject area. Bringing together the concepts, techniques and systems associated with the dynamics and control of smart structures, it comprehensively reviews the differing smart materials that are employed in the development of the smart structures and covers several recent developments in the field of structural dynamics. Dynamics of Smart Structures has been developed to complement the author's new interdisciplinary programme of study at Queen Mary, University of London that includes courses on emerging and new technologies such as biomimetic robotics, smart composite structures, micro-electro-mechanical systems (MEMS) and their applications and prosthetic control systems. It includes chapters on smart materials and structures, transducers for smart structures, fundamentals of structural control, dynamics of continuous structures, dynamics of plates and plate-like structures, dynamics of piezoelectric media, mechanics of electro-actuated composite structures, dynamics of thermo-elastic media: shape memory alloys, and controller designs for flexible structures.

A text/reference on analysis of structures that deform in use. Presents a new, integrated approach to analytical dynamics, structural dynamics and control theory and goes beyond classical dynamics of rigid bodies to incorporate analysis of flexibility of structures. Includes real-world examples of applications such as robotics, precision machinery and aircraft structures.

In Stochastic Dynamics of Structures, Li and Chen present a unified view of the theory and techniques for stochastic dynamics analysis, prediction of reliability, and system control of structures within the innovative theoretical framework of physical stochastic systems. The authors outline the fundamental concepts of random variables, stochastic process and random field, and orthogonal expansion of random functions. Readers will gain insight into core concepts such as stochastic process models for typical dynamic excitations of structures, stochastic finite element, and random vibration analysis. Li and Chen also cover advanced topics, including the theory of and elaborate numerical methods for probability density evolution analysis of stochastic dynamical systems, reliability-based design, and performance control of structures. Stochastic Dynamics of Structures presents techniques for researchers and graduate students in a wide variety of engineering fields: civil engineering, mechanical engineering, aerospace and aeronautics, marine and offshore engineering, ship engineering, and applied mechanics. Practicing engineers will benefit from the concise review of random vibration theory and the new methods introduced in the later chapters. "The book is a valuable contribution to the continuing development of the field of stochastic structural dynamics, including the recent discoveries and developments by the authors of the probability density evolution method (PDEM) and its applications to the assessment of the dynamic reliability and control of complex structures through the equivalent extreme-value distribution." —A. H-S. Ang, NAE, Hon. Mem. ASCE, Research Professor, University of California, Irvine, USA "The authors have made a concerted effort to present a responsible and even holistic account of modern stochastic dynamics. Beyond the traditional concepts, they also discuss theoretical tools of recent currency such as the Karhunen-Loeve expansion, evolutionary power spectra, etc. The theoretical developments are properly supplemented by examples from earthquake, wind, and ocean engineering. The book is integrated by also comprising several useful appendices, and an exhaustive list of references; it will be an indispensable tool for students, researchers, and practitioners endeavoring in its thematic field." —Pol Spanos, NAE, Ryon Chair in Engineering, Rice University, Houston, USA