Engineering and the Environment, University of Southampton

Knowledge and understanding
Having successfully completed the module, you will be able to demonstrate knowledge and understanding of:

• The sources of vibration and how to determine the number of incoherent vibration sources by measurement.
• Mobility and impedance techniques.
• How to control vibration using a variety of techniques.
• How to assess the effectiveness of vibration control measures.

Cognitive (thinking) skills
Having successfully completed the module, you will be able to:

• Read, understand and interpret the literature relating to vibration control.
• Assess a vibration control problem, develop solutions to solve the problem and design an experiment to assess the solution.

Practical, subject specific skills
Having sucessfully completed the module, you will be able to:

• Carry out modelling and measurements to assess a vibration problem.
• Design and apply appropriate vibration control measures.

Key transferable skills
Having successfully completed the module, you will be better able to:

• Carry out experimental work.
• Write-up laboratory work.
• Use of MATLAB.

The aim of this module is to:

• Give students fundamental knowledge in vibration control.

• To give students an appreciation of the sources of vibration and to introduce techniques of source identification and transfer path analysis.
• To introduce a framework by which complex structures can be described to enable the effectiveness of vibration control measures to be assessed.
• To introduce the principles behind vibration control techniques, and give an appreciation of the physical processes involved when they are applied.
• To introduce students to various techniques of vibration control.

Sources of vibration

• Types of source mechanisms; rotation, impact, flow, self-excited.
• Description of vibration generated by these mechanisms; deterministic, random, transient.

Source identification and transfer path analysis

• Development of matrix techniques for transfer path analyis in multi-input-multi-output systems.
• Identification and ranking of independent source contributions using singular value decomposition.
• Principle component analysis and virtual coherence techniques.
• Case study: Analysis of vehicle vibration due to multiple sources.

Mechanical impedance and mobility techniques

• Impedance and mobility concepts; impedance and mobility of simple elements (mass stiffness and damping, infinite beams and plates) .
• System modelling using impedance and mobility approach; characterisation of sources, transmission paths and receivers.
• Computation using transfer matrices from impedance and mobility matrices .
• Measurement of impedance and mobility.
• Coupling of system components together to predict the overall response.

Control by isolation

• Limitations of the simple model.
• Use of the impedance and mobility approach in the design of isolation systems; engine isolators, aircraft structures and piping systems.

Control by the addition of vibration neutralisers and tuned mass dampers

• Control of deterministic vibration using neutralisers.
• Damping of structures subject to broadband excitation using tuned mass dampers.

Control by damping treatments

• Review of damping mechanisms.
• Characteristics of damping materials and use of constrained and unconstrained damping treatments.

This is a one-week module.

Lectures in the classroom typically occur in the mornings followed in the afternoons by laboratory work to underpin the knowledge gained in the lectures.

Some demonstrations are given in the morning lectures.

Hands-on laboratory work for the students in the afternoons. The students are arranged in four groups of three so that each student participates in the experiment.

The students have to write-up two laboratories that are chosen by the course co-ordinator. They also have to do a written assignment which requires analysis of a problem and the design of suitable vibration control measures together with an assessment of the solution. Students are encouraged to read supporting texts and a booklist is provided.

Core text

Shock and Vibration Handbook
3rd Edition, 1988, C M Harris, McGraw-Hill
New York
0070267995

Advanced Applications in Acoustics Noise and Vibration, 2004, F J Fahy
J G Walker, Spon Press

Machinery Noise and Diagnostics, 1987, R H Lyon, Butterworths,
Boston, Mass
0409901016

Modal Testing: Theory, Practice, and Application
2nd Edition, D J Ewins, Baldock, Herts: Research Studies Press, 2000
ISBN 0863802184 hbk
ISBN 0471975184 Wiley: hbk

Noise and Vibration Control Engineering, 1992, L L Beranek
I Vér (eds), John Wiley
0471617512

Noise and Vibration, 1982, R G White
J G Walker, Ellis Horwood, Chichester