Engineering and the Environment, University of Southampton

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

• Use advanced techniques for the measurement of aspects of sound and vibration phenomena and data processing.

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

• Read and understand the literature relating to experimental studies and measurement techniques in advanced acoustics, vibration and signal processing.
• Critically review experimental procedures and develop further experimental procedures.

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

• Demonstrate expertise in advanced measurement methods and an ability to prepare high quality technical reports.

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

• Undertake experimental work.
• Read and write technical reports.

The aims of this module are to:

• Develop aspects of sound and vibration measurement, data analysis and interpretation skills together with report writing skills.

• To provide you with advanced measurement, data analysis and interpretation tasks under close supervision and to present you with associated reporting tasks.

The student will select any three of the following topics.

AMT 1 Dual channel frequency analysis (Pre-requisite ISVR6032 Signal Processing)

• Determination of frequency response functions using auto and cross spectral densities
• Windowing and segment averaging
• Coherence
• Effects of noise on the computation of the FRF
• Influence of FFT size and number of averages on spectral estimates

AMT 2 Sound absorption measurement (Pre-requisite ISVR6030 Fundamentals of Acoustics)

• Absorption coefficient
• Use of reverberation chamber
• Use of standing wave tube
• Diffuse field energy balance
• One-dimensional standing wave fields
• Schroeder (backwards) integration

AMT 3 Measuring FRFs using a shaker (Pre-requisite ISVR6031 Fundamentals of Vibration)

• Assembly of rig
• Stepped sine technique / nonlinearity
• Choice of excitation signal (random, burst random, chirp) when using FFT technique
• Checking measurements
• Advantages and limitations of shaker testing

AMT 4 Acoustic source reconstruction (Pre-requisite ISVR6030 Fundamentals of Acoustics)

• The SVD technique for source identification
• Coherence as a tool for source identification
• The Rayleigh criterion as a resolution limit for source identification
• Near field and far fields
• The reverberation radius

AMT 5 Vibration testing using an impact hammer (Pre-requisite ISVR6031 Fundamentals of Vibration)

• Selection of instrumentation
• Signal processign issues
• Point and transfer FRF measurement
• Modes of vibration: natural frequencies and mode shapes
• Experimental modal analysis: peak response and circle fit methods
• Input power, modal density

Introductory lecture overviewing the module and reviewing experimental method, laboratories and reports.

3 Laboratory sessions of up to 4 hours each. Teaching groups are normally very small (usually from 2 or 3 students to a maximum of 6 depending on the apparatus used). Each laboratory is preceded by an introductory lecture.

Laboratories include a work-sheet although you are not confined to work exclusively from this sheet and are encouraged to broaden your measurement capability whenever possible.

Assessment of the laboratory reports tests your ability to make good quality measurements and to apply advanced measurement techniques.

Secondary text

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

Vibration Testing, Theory and Practice, K G McConnell, Wiley

Technical Reviews 1 and 2, Anon, Bruel and Kjaer

Fundamentals of Signal Processing for Sound and Vibration Engineers, K Shin
J K Hammond, Wiley 2008
ISBN 0470511885