This second edition follows the previous one after about two years. Apart from correcting a number of printing errors, few additions have been introduced. In the chapter on the finite element method, a short summary on finite elements in time (four-dimensional finite elements) has been introduced. In the chapter on rotordynamics, two new graphical representations are used; namely, the roots locus plot for free whirling and a tri-dimensional plot for the forced response for which the designation of "orbital tubes" has been proposed. The former has been borrowed from controlled systems dynamics, where it is widely used, while the latter is made practical by the availability of powerful graphical tools for postprocessing numerical or experimental results. As a last point, a more detailed description of the behaviour of magnetic bearings has been introduced in Chapter 6. Torino, September 1994 G. Genta Preface The present book originates from the need felt by the author to give a systematic form to the contents of the lectures he gives to mechanical and aeronautical engineering students of the Technical University (Politecnico) of Torino, within the frames of the courses of Principles and Methodologies of Mechanical Design and Construction of Aircraft Engines. Its main aim is that of summarizing the funda mentals of mechanics of vibrations to give the needed theoretical background to the engineer who has to deal with vibration analysis and to show a number of design applications of the theory.
Auflage
Sprache
Verlagsort
Verlagsgruppe
Illustrationen
ISBN-13
978-1-4684-0236-0 (9781468402360)
DOI
10.1007/978-1-4684-0236-0
Schweitzer Klassifikation
1. Discrete linear systems.- 1.1 Systems with a single degree of freedom.- 1.2 Systems with many degrees of freedom.- 1.3 State space.- 1.4 Free behaviour.- 1.5 Uncoupling of the equations of motion.- 1.6 Excitation due to the motion of the constraints.- 1.7 Forced oscillations with harmonic excitation.- 1.8 System with structural damping.- 1.9 Systems with frequency dependent parameters.- 1.10 Co-ordinate transformation based on Ritz vectors.- 1.11 Structural modifications.- 1.12 Parameter identification.- 1.13 Laplace transforms, block diagrams and transfer functions.- 1.14 Response to non-harmonic excitation.- 1.15 Short account on random vibrations.- 1.16 Concluding examples.- 1.17 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 the 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 systems.- 3.6 Forced oscillations of the damped system.- 3.7 Parametrically excited systems.- 3.8 An outline on chaotic vibrations.- 3.9 Exercises.- 4. Dynamics of rotating machinery.- 4.1 Rotors and structures.- 4.2 Vibration of rotors: the Campbell diagram.- 4.3 Forced vibrations of rotors: critical speeds.- 4.4 Fields of instability.- 4.5 The linear "Jeffcott rotor".- 4.6 Model with 4 degrees of freedom: gyroscopic effect.- 4.7 Dynamic study of rotors with many degrees of freedom.- 4.8 Non isotropicsystems.- 4.9 Introduction to nonlinear rotordynamics.- 4.10 Rotors on hydrodynamic bearings (oil whirl and oil whip).- 4.11 Flexural vibration dampers.- 4.12 Signature of rotating machinery.- 4.13 Rotor balancing.- 4.14 Exercises.- 5. Dynamic problems of reciprocating machines.- 5.1 Specific problems of reciprocating machines.- 5.2 "Equivalent system" for the study of torsional vibrations.- 5.3 Computation of the natural frequencies.- 5.4 Forced vibrations.- 5.5 Torsional instability of crank mechanisms.- 5.6 Dampers for torsional vibrations.- 5.7 Experimental measurements 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 discrete linear systems.- 6.4 Modal approach to structural control.- 6.5 Dynamic study of rotors on magnetic bearings.- 6.6 Exercises.- Appendix. Solution methods.- A.1 General considerations.- A.2 Solution of linear sets of equations.- A.3 Computation of the eigenfrequencies.- A.4 Solution of nonlinear sets of equations.- A.5 Numerical integration in time of the equation of motion.
