Finite Element And Boundary Methods In Structural Acoustics And Vibration

Effectively Construct Integral Formulations Suitable for Numerical ImplementationFinite Element and Boundary Methods in Structural Acoustics and Vibration provides a unique and in-depth presentation of the finite element method (FEM) and the boundary element method (BEM) in structural acoustics and vibrations. It illustrates the principles using a

Vibration and structural acoustics analysis has become an essential requirement for high-quality structural and mechanical design in order to assure acoustic comfort and the integrity, reliability and fail-safe behavior of structures and machines. The underlying technologies of this field of multidisciplinary research are evolving very fast and their dissemination is usually scattered over different and complementary scientific and technical publication means. In order to make it easy for developers and technology end-users to follow the latest developments and news in the field, this book collects into a single volume selected, extended, updated and revised versions of papers presented at the Symposium on Vibration and Structural Acoustics Analysis, coordinated by J. Dias Rodrigues and C. M. A. Vasques, which was organised as part of the 3rd International Conference on Integrity, Reliability & Failure (IRF’2009), co-chaired by J. F. Silva Gomes and Shaker A. Meguid, held at the Faculty of Engineering of the University of Porto, Portugal, 20-24 July 2009. These papers where chosen from the more than 60 papers presented at the conference symposium. Written by experienced practitioners and researchers in the field, this book brings together recent developments in the field, spanning across a broad range of themes: vibration analysis, analytical and computational structural acoustics and vibration, material systems and technologies for noise and vibration control, vibration-based structural health monitoring/evaluation, machinery noise/vibration and diagnostics, experimental testing in vibration and structural acoustics, applications and case studies in structural acoustics and vibration. Each chapter presents and describes the state of the art, presents current research results and discusses the need for future developments in a particular aspect of vibration and structural acoustics analysis. The book is envisaged to be an appealing text for newcomers to the subject and a useful research study tool for advanced students and faculty members. Practitioners and researchers may also find this book a one-stop reference that addresses current and future challenges in this field. The variety of case studies is expected to stimulate a holistic view of sound and vibration and related fields and to appeal to a broad spectrum of engineers such as the ones in the mechanical, aeronautical, aerospace, civil and electrical communities.

The book describes analytical methods (based primarily on classical modal synthesis), the Finite Element Method (FEM), Boundary Element Method (BEM), Statistical Energy Analysis (SEA), Energy Finite Element Analysis (EFEA), Hybrid Methods (FEM-SEA and Transfer Path Analysis), and Wave-Based Methods. The book also includes procedures for designing noise and vibration control treatments, optimizing structures for reduced vibration and noise, and estimating the uncertainties in analysis results. Written by several well-known authors, each chapter includes theoretical formulations, along with practical applications to actual structural-acoustic systems. Readers will learn how to use vibroacoustic analysis methods in product design and development; how to perform transient, frequency (deterministic and random), and statistical vibroacoustic analyses; and how to choose appropriate structural and acoustic computational methods for their applications. The book can be used as a general reference for practicing engineers, or as a text for a technical short course or graduate course.

Computational methods within structural acoustics, vibration and fluid-structure interaction are powerful tools for investigating acoustic and structural-acoustic problems in many sectors of industry; in the building industry regarding room acoustics, in the car industry and aeronautical industry for optimizing structural components with regard to vibrations characteristics etc. It is on the verge of becoming a common tool for noise characterization and design for optimizing structural properties and geometries in order to accomplish a desired acoustic environment. The book covers the field of computational mechanics, and then moved into the field of formulations of multiphysics and multiscale. The book is addressed to graduate level, PhD students and young researchers interested in structural dynamics, vibrations and acoustics. It is also suitable for industrial researchers in mechanical, aeronautical and civil engineering with a professional interest in structural dynamics, vibrations and acoustics or involved in questions regarding noise characterization and reduction in building, car, plane, space, train, industries by means of computer simulations.

The book provides a survey of numerical methods for acoustics, namely the finite element method (FEM) and the boundary element method (BEM). It is the first book summarizing FEM and BEM (and optimization) for acoustics. The book shows that both methods can be effectively used for many other cases, FEM even for open domains and BEM for closed ones. Emphasis of the book is put on numerical aspects and on treatment of the exterior problem in acoustics, i.e. noise radiation.

The Boundary Element Method, or BEM, is a powerful numerical analysis tool with particular advantages over other analytical methods. With research in this area increasing rapidly and more uses for the method appearing, this timely book provides a full chronological review of all techniques that have been proposed so far, covering not only the fundamentals of the BEM but also a wealth of information on related computational analysis techniques and formulations, and their applications in engineering, physics and mathematics. An indispensable handbook and source of inspiration for researchers and professionals in these fields, this book is also an ideal textbook for graduate engineering students.

Structural Acoustics and Vibration presents the modeling of vibrations of complex structures coupled with acoustic fluids in the low and medium frequency ranges. It is devoted to mechanical models, variationalformulations and discretization for calculating linear vibrations in the frequency domain of complex structures. The book includes theoretical formulations which are directly applicable to develop computer codes for the numerical simulation of complex systems, and gives a general scientific strategy to solve various complex structural acoustics problems in different areas such as spacecraft, aircraft, automobiles, and naval structures. The researcher may directly apply the material of the book to practical problems such as acoustic pollution, the comfort of passengers, and acoustic loads induced by propellers. Structural Acoustics and Vibration considers the mechanical and numerical aspects of the problem, and gives original solutions to the predictability of vibrations of complex structures interacting with internal and external, liquid and gaseous fluids. It is a self-contained general synthesis with a didactic presentation and fills the gap between analytical methods applied to simple geometries and statistical methods, which are useful in high frequency structural acoustic problems. Provides for the first time complex structures in scientific literature Presents a self-contained general synthesis with a didactic presentation Integrates the most advanced research topics on the subject Enables the researcher to solve complex structural acoustics problems in areas such as spacecraft, aircraft, automobiles, and naval structures Fills the gap between analytical methods applied to simple geometries and statistical methods Contains advanced mechanical and numerical modeling Provides appropriate formulations directly applicable for developing computer codes for the numerical simulation of complex systemssystems

Finite Element Programs for Structural Vibrations presents detailed descriptions of how to use six computer programs (written in Fortran 77) to determine the resonant frequencies of one, two, and three-dimensional skeletal structures through the finite element method. Chapter 1 is on "The Finite Element Method" and Chapter 2 demonstrates, with the aid of hand calculations, the finite element solution of some smaller structures. Chapter 3 covers "The Modular Approach", and Chapters 4 to 9 describe the six computer programs, with a large number of worked examples. The six computer programs are given in Appendices I through VI, and on a 3 1/2'' disk included with the book. The programs are suitable for use on IBM (or compatible) PC (640K or more) or minicomputer.