33971 - Vibration Mechanics M

Academic Year 2019/2020

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Mechanical Engineering (cod. 0938)

    Also valid for Second cycle degree programme (LM) in Mechanical Engineering (cod. 0938)

Learning outcomes

Students are introduced to procedures and methods for identification, design, analysis of dynamical models of mechanical systems.

Course contents

This course discusses main techniques commonly employed in experimental identification of mechanical systems, showing that some useful results can be obtained in solving problems arising in the industrial practice. The theoretical basis concerning the vibrations of single- and multi-degree-of-freedom mechanical systems is first outlined. Discretization of continuous systems is also considered, and some techniques are briefly illustrated. Identification of structural and modal system parameters then follows, and some time and frequency-based techniques are shown and discussed in detail.

Some practical examples, concerning the application of some previously defined techniques, are also reported. Identification of the structure of a machine tool is discussed, and some useful results concerning the simulation of its dynamical response and the effect of localized structural modifications is also reported.

A diagnostic application, concerning the identification and localization of a damage (crack) in an operating rotating shaft is also discussed in detail.

— Free and forced vibration of single and multi-degree-of-freedom systems, real and complex damping ;

— structural v/s modal model;

— experimental modal analysis (EMA): time and frequency domain identification techniques;

— EMA applications:

_ response simulations;

_ structural modifications;

— application examples:

_ machine tool model identification and structural modification;

_ crack identification and localization on a rotor.

Readings/Bibliography

References

-   Bendat, J.S., Piersol, A.G., Random Data Analysis and Measurement Procedures, III ed., Wiley, N.Y., 2000;

-   Bendat, J.S., Piersol, A.G., Engineering Applications of Correlation and Spectral Analysis, II ed., Wiley, N.Y., 1993;

-   Bendat, J.S., Nonlinear System Techniques and Applications, Wiley, N.Y., 1998;

- Cochin, I., Cadwallender, W., Analysis and Design of Dynamic Systems, III ed., Addison-Wesley, Reading, 1997;

- de Silva, C., W., Vibrations Fundamentals and Practice, CRC Press, Boca Raton, 2000, http://www.engnetbase.com/ejournals/books/book_summary/summary.asp?id=426;

- Ewins, D. J., Modal Testing, II ed., Research Studies Press, Philadelfia, 2000;

- Fahy, F., Sound and Structural Vibration, Academic Press, London, 1985,

- Inman, D.J., Vibration with control measurement and stability, Prentice-Hall, London, 1989;

- James, M.L., Smith, G.M., Wolford, .J.C., Whaley, P.W., Vibration of Mechanical and Structural Systems, Harper & Row, NY, 1989;

- McConnell, K.G., Vibration Testing theory and practice, Wiley, N.Y., 1995;

- Meirovitch, L., Computational Methods in Structural Mechanics, Sijtoff & Noordhoff, Rockville, Usa, 1980

- Newland, D.E., Random Vibrations and Spectral Analysis, II ed., Longman, N.Y., 1984;

- Newland, D.E., Mechanical Vibration Analysis and Computation, Longman, Singapore, 1989;

- Thomson, W.T., Theory of vibration with applications, Chapman &Hall, London, IV ed., 1993

- Przemienecki, J.S., Theory of Matrix Structural Analysis, McGraw-Hill, N.Y. 1968

Teaching methods

Lectures with blackboard and slides and notebook+overhead projector.

Assessment methods

Oral examination: discussion of topics listed in the program. Discussion of a specific topic or solution of a numerical application concerning mechanical vibrations.

Teaching tools

Lectures with blackboard and slides and notebook+overhead projector.

Office hours

See the website of Giuseppe Catania

SDGs

Industry, innovation and infrastructure

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.