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ULTRASONIC RESONANCE SPECTROSCOPY QUALITY ASSURANCE TESTING OF: CONCRETE, AEROSPACE COMPONENTS AND DIECAST ALUMINIUM COMPONENTS

Objective


This project has shown that resonance spectroscopy, when used to test a whole sample (global testing) and when a neural network is used for interpretation is an intrinsically simple test and can be used successfully to assess the mechanical quality of industrial components. It involves no surface scanning and no operator is needed to interpret data. The project has also shown that resonance spectroscopy can be used successfully for local testing with a neural network for interpretation. The output of the neural network can be as simple as either Pass or Fail. The only manipulation of the object required is to place the transducer pair in contact with the sample for the test. For these reasons resonance spectroscopy has considerable potential to be highly cost-effective tool for quality assurance of industrial parts made on a production-line. Resonance spectroscopy has been much less successful when it is used without an effective aid to interpretation - when that the operator is substantially responsible for deciding the quality of the inspected component and it cannot be recommended for use in this particular way. However, resonance spectroscopy when aided by a neural network has proved to be a highly effective tool for inspecting a range of industrial components.
Quality assurance inspection is known to be unsatisfactory for the following industrially important materials and components : concrete, concrete structures, composite honeycomb aerospace materials and high pressure die-cast aluminium components. Improvements sought by industry include : introducing new methods to allow testing for the first time, reducing cost per test, increasing sensitivity to flaw size, in-service monitoring, feature selectivity and pass/fail decision making.

It is proposed to investigate only one method of testing - the method of ultrasonic (and sonic) resonance spectroscopy. Although the method is long-established it is not used to its full potential. Important weaknesses in previous embodiments of the method have been identified which cause distortion to measured spectrums and hence severely reduce its effectiveness. An objective here is to collect spectrums accurately. Another objective is to provide software tools to help interpret the spectrums and hence improve the overall effectiveness of the method.

Two common characteristics of the materials of interest are (i) that they are all difficult or impossible to test by the ultrasonic pulse-echo method and (ii) that they all have fairly low acoustic attenuation at frequencies of interest. Due to the low attenuation standing wave patterns can be established in them and the method of ultrasonic resonance spectroscopy can be applied, however, the challenge remains to interpret spectrum. The range of frequencies of interest is from typically 10Hz (case of concrete structures) to 10MHz (case of aerospace components).

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Instrumentation Innovation Ltd
Address
Church Farm Barn Horse Ware Over
CB4 5NX Cambridge
United Kingdom

Participants (10)

Alcatel
France
Address
26 Avenue J F Champollion
31077 Toulouse
ISOTEST LTD
Italy
Address
Via Roma 8
10090 Reano
KING'S COLLEGE LONDON
United Kingdom
Address
Strand
WC2R 2LS London
Magma Gießereitechnologie Gesellschaft für Gießerei-, Simulations- und Regeltechnik mbH
Germany
Address
Werner-heisenberg-straße 14
52477 Alsdorf
Petroleum Science and Technology Institute
United Kingdom
Address
Dunedin House Ravelston Terrace
EH4 3EX Edinburgh
Rendel Palmer and Tritton Economic Studies Group Ltd
United Kingdom
Address
61 Southwark Street
SE1 1SA London
TECHSONIC SARL
France
Address
Route Des Alisiers Bat. B
06600 Antibes
Taywood Engineering Ltd
United Kingdom
Address
Taywood House 345 Ruislip Road
UB1 2QX Southall
Transport Research Laboratory (TRL)
United Kingdom
Address
Old Wokingham Road
RG11 6AU Crowthorne
UNIV UPPSALA
Sweden
Address
Box 534
75121 Uppsala