Indice

 Introduction

1 Discrete Linear Systems

1.1 Systems with a single degree of freedom

1.2  Systems with many degrees of freedom

1.3  Lagrange equations

1.4  State space

1.5  Free behaviour

1.6  Uncoupling of the equations of motion: Space of the configurations

1.7  Uncoupling of the equations of motion: State space

1.8  Excitation due to the motion of the constraints

1.9  Forced oscillations with harmonic excitation

1.10  Systems with structural damping

1.11  Systems with frequency-dependent parameters

1.12  Coordinate transformation based on Ritz vectors

1.13  Structural modification

1.14  Parameter identification

1.15  Laplace transforms, block diagrams, and transfer functions

1.16  Response to nonharmonic excitation

1.17  Short account of random vibrations

1.18  Concluding examples

1.19  Exercises

2   Continuous Linear Systems

2.1  General considerations

2.2  Beams and bars

2.3  Flexural vibration of rectangular plates

2.4  Propagation of elastic waves in taut strings and pipes

2.5  The assumed-modes methods

2.6  Lumped-parameters methods

2.7  The finite element method

2.8  Reduction of the number of degrees of freedom

2.9  Exercises

3   Nonlinear Systems

3.1  Linear versus nonlinear systems

3.2  Equation of motion

3.3  Free oscillations of the undamped system

3.4  Forced oscillations of the undamped system

3.5  Free oscillations of the damped system

3.6  Forced oscillations of the damped system

3.7  Parametrically excited systems

3.8  An outline of chaotic vibrations

3.9  Exercises

4   Dynamic Behaviour of Rotating Machinery

4.1  Rotors and structures

4.2  Fields of instability

4.3  The linear Jeffcott rotor

4.4  Model with four degrees of freedom: Gyroscopic effect

4.5  Dynamic study of rotors with many degrees of freedom

4.6  Nonisotropic systems

4.7  Introduction to nonlinear rotor dynamics

4.8  Rotors on hydrodynamic bearings (oil whirl and oil whip)

4.9  Flexural vibration dampers

4.10  Signature of rotating machinery

4.11  Rotor balancing

4.12  Exercises

5  Dynamic Problems of Reciprocating Machines

5.1  Specific problems of reciprocating machines

5.2  Equivalent system for the study of torsional vibrations

5.4  Forced vibrations

5.5  Torsional instability of crank mechanisms

5.6  Dampers for torsional vibrations

5.7  Experimental measurement of torsional vibrations

5.8  Axial vibrations of crankshafts

5.9  Short outline on balancing of reciprocating machines

5.10  Exercises

6   Short Outline on Controlled and Active Systems

6.1  General considerations

6.2  Control systems

6.3  Controlled linear systems

6.4  Modal approach to structural control

6.5  Dynamic study of rotors on magnetic bearings

6.6  Exercises

Appendix 1. Solution Methods

A.1  General considerations

A.2  Solution of linear sets of equations

A.3  Computation of eigenfrequencies

A.4  Solution of nonlinear sets of equations

A.5  Numerical integration in time of the equation of motion

…This present version of Vibration of Structures and Machines by Giancarlo Genta is the second edition of a work first published in 1993 - a new edition after only two years! Does this book meet a need and form a valuable addition to the literature? For a range of reasons it is good to be able to answer this query positively. I fear that, certainly in British universities, Giancarlo Genta's work is not directed at the undergraduate market, although as a work of scholarship it should be essential reading for teachers of mechanical vibration. The book provides a good theoretical underpinning to a sound knowledge and understanding of vibration phenomena, their analysis and numerical procedures for their solution. It is not a book for initial reading in the subject, but teachers and industrial engineers with experience in the field will enjoy the reinforcement of their understanding of the fundamentals provided by the firm theoretical grasp offered by the work. It is thoughtfully written and makes clear, easy reading in the context of experience. With some occasional minor clumsy phrasing the overall presentation in English is fine.

The price of the book, some £50, is not low, but it is unfortunately a reflection of current costs of many similar texts. The book is well produced and presented. It should certainly appear on institution, company and department library shelves where researchers, teachers and designers are active in the vibration area.

The book is based on lectures given by the author to students in mechanical and aeronautical engineering at the Technical University of Turin. As such it highlights the different approach to engineering education in many parts of mainland Europe compared with that adopted in the United Kingdom, restricted as the latter often is by the mathematical limitations of the students. Nevertheless, the book can certainly be read with profit by postgraduate and research students in Britain, not as an introductory text but as a means of enhancing their understanding of vibration and placing their immediate problems in a wider scenario.

The book starts with a thoughtful introduction highlighting typical sources of practical vibration problems and summarizing various, theoretical and numerical, solution procedures. It clearly sets the study of vibration in the context of design and production. Chapter 1 provides a thorough and comprehensive introduction to the analysis of discrete, linear systems, covering all the required areas and applications including structural and viscous damping. Numerical/computing procedures are encouraged, but cautionary advice is given concerning the overconfidence that large-scale computing can induce - physical insight remains essential. The text leads naturally into Chapter 2 on continuous linear models for vibrating systems, principally the flexural vibration of beams/shafts. The continuous analysis is used to establish discretization techniques, parti'dularly the finite element method, on a sound theoretical basis, leading to adequate mathematical models and the important ability to evaluate critically the results of computational procedures. Chapter 3 explores the elements of the vibration of non‑linear systems, mainly in the context of systems with one degree of freedom. Coverage includes the Ritz averaging technique, Dufiing's equation with no damping, with viscous damping or with structural damping, Van der Pol's method and Poincare mapping. The chapter concludes with parametrically excited systems and an outline of chaotic vibrations.

The reviewer, partly because of his own research interests perhaps, particularly values two extensive chapters (Chapters 4 and 5) devoted to rotordynamics, the vibration of rotating machinery and the dynamics of reciprocating machines. Apart from the inherent interest of these topics, rotating machinery is a source of many practical vibration problems which can lead to discomfort, unreliability and dangerous operation. The coverage of vibrations in rotating machinery is comprehensive and is intended to be more in the context of engineering applications than the previous chapters. The scope extends to the inclusion of developing topics and procedures which at present are still the subject of research investigations. The text finishes with a short outline on controlled and active systems, including the study of rotors supported on magnetic bearings - all very much growth areas of research and design practice.

In summary, Giancarlo Genta has provided a valuable addition to the vibration literature, especially in providing a thorough theoretical framework, so that the vibration specialist can see practical and theoretical problems in a wider context. The text is not aimed at undergraduate students in the United Kingdom, but can be read with interest and insight by the industrial design practitioner and/or teacher.

(A G Parkinson, Proc. of the Inst. Of Mech. Eng.)

This is the second edition of this outstanding book. It follows the first edition after just two years, which shows that the book has met with great interest among readers…

… The book presents a really broad scope of vibration problems of machines and structures; the broadest, I believe, of all textbooks on vibration. This fact limits, of course, the extent of some special classes of problems. However, the book provides a lot of information and up‑to‑date knowledge on vibration. The good presentation is strpportcd by instructive illustrations. The examples offer useful exercises for students.

This very good book can be recommended not only to students - especially to postgraduates - but also to designers and to any one looking for better knowledge of vibration.

(A: Tondl, Journal of Sound and Vibration)