29th European Conference on Acoustic Emission Testing 2010
Vienna, Austria, September 8-10, 2010
EWGAE Vienna, September 2010
Copyright © 2010 European Working Group on Acoustic Emission and TÜV AUSTRIA SERVICES GMBH
All rights reserved. No part of the contents of this book may be reproduced or transmitted in any form or by any means without written permission of the publisher or the author. Neither the publisher nor the producer is responsible for the use which might be made of the following information. Every effort has been made to ensure that these proceedings are correct.
An online version of these proceedings is available at www.ndt.net
EWGAE-29 Organizing Committee
Purpose of Conference
This 29th Conference is arranged by the Institute of Technical Physics, a division of TÜV AUSTRIA SERVICES GMBH on behalf of The European Working Group on Acoustic Emission (EWGAE).
The European Working Group on Acoustic Emission
The first European meeting on the subject was the "Institute of Physics Conference on Acoustic Emission" which was organized by Adrian Pollock and held in March 1972 at Imperial College in London. Fifteen papers from throughout Europe and USA were presented. The success of this conference established both the interest and the need for forming a working group. Consequently, Pollock and Birchon organized the European Stress Wave Emission Working Group, which held its first meeting in November 1972, at the Admiralty Materials Laboratory in England. During their second meeting at Battelle-Institut in September 1973, the group formally adopted their present name, European Working Group on Acoustic Emission. The original letterhead logo was designed by Patricia Preston, graphics designer at Cambridge Consultants. During the late 1970s and early 1980s, the Codes Subgroup of EWGAE published 5 codes of practice. In 1991, the work of this group was taken up by a new working group on AE (WG7) within TC138, the Technical Committee for NDT within CEN. This working group is comprised of national representatives who have been nominated by their respective National Standards Institutions. The first Convenor of WG-7 was Emilio Fontana of CISE, Italy. After his retirement in 2003, Peter Tscheliesnig of TÜV Austria was appointed and is currently serving as Secretary of the group. Since 2000, the following standards for AE, developed by TC138-WG7 have been published:
Current work items deal with testing of fiber-reinforced polymers, AE testing for the detection of corrosion within metallic surrounding filled with liquid, and reviews of EN 13554 and 13477-2. These Standards have significantly contributed to the today's acceptance of the AE testing method in Europe. During the last 5 years, active members within the CEN TC138-WG7 were: P. Tscheliesnig (Austria), C. Herve and J.C. Lenain (France), J. Bohse and H. Vallen (Germany), A. Anastasopoulos (Greece), C. De Petris (Italy), E. Romero (Spain), H. Schoorlemmer (The Netherlands), L. Rogers and P. Cole (U.K.) Since 2000, the European Standard for Qualification and Certification of NDT Personnel, EN473, covers also the AE testing method (abbreviation: AT) and defines details for education and certification.
During 2005, the British Institute of Non-Destructive testing has established an Acoustic Emission Working Group to develop the Acoustic Emission sections of their PCN scheme which provides an international programme for the certification of testing, inspection and condition monitoring personnel which satisfies the requirements of numerous European and international standards. Members of this group include K Holford, T Bradshaw, D Mba, M Forde, Trevor Holroyd, Winfield Stewart, Ian Taylor, John O'Brien, R Reuben, Stuart Courtenay and Martin Peacock. The following EWGAE conferences were held since 2000: Senlis/Paris, France (June 2000); Prague, Czech Republic (Sept. 2002); Berlin, Germany (Sept. 2004); Cardiff, UK (Sept. 2006); Krakow (Sept. 2008) and the increasing desire to exchange ideas and experience is reflected in the number of delegates: 99, 108, 150, 100, 121. AE Testing in Europe is now well established in several important areas of proof testing, inservice monitoring, corrosion and leak detection. Development of the technology continues to be driven by the needs of the industry to reduce inspection and maintenance costs while preserving its assets and personnel safety. The advancement of PC technology has positively influenced new developments in hardware and software for powerful and user-friendly testing equipment.
Sources: T.F. Drouillard, Adv. in AE-2007, pp. 1-10; H. Vallen, 26th EWGAE Proc. Vol. 1, DGZfP, pp. iii-v; Report for EWGAE 2006, Cardiff, UK
The Institute for Technical Physics of
The acoustic emission examination (AE) is a non-destructive testing and inspection method to locate failures and leakages within pressure equipment. Acoustic emission testing (AT) gives an overall view of the physical condition and density of the tested structure. Detecting and locating possibly existing failures and leakages is effected with the help of a classical physical principle. It is applied for the advantage of industry by means of today's data recording and processing.
Even the blacksmiths of the ancient world realized that metals released audible soundwaves when subject to load, bending, pressure or pulling (e.g. "screaming tin") and avoided the overloading of materials with simple procedures. Sound emissions result from defects in the different materials or leakages in containers. When energy is applied, voltage discharges in the form of sound impulses. The resulting energy is recorded by sensors applied on the surface of the examined unit.
The sound source can be located by means of chronological measurement of the impulses with the help of an algorithm. Therefore AE is an ideal integral inspection method for larger pressure vessels. Due to the results only selected areas must be subjected to the additional conventional non-destructive examination.
One of the most essential advantages of acoustic emission examination is the feasibility to examine pressure equipment and storage tanks with regard to leakages and corrosion "online", i.e. during operation or short standstills. The tank or pipe does not always have to be excluded from the production procedure. In many cases the reliability of information gained by means of AE is higher than the results of normal pressure tests or visual internal examinations. This versatile testing procedure is state of the art and combines highest possible safety with optimal availability of production factors.
TÜV Austria has been applying the acoustic emission examination since the seventies and has gradually developed and improved this testing method. TÜV Austria plays a leading role in Europe in this field and is your competent partner for efficient resource management.
Dipl.-Ing. Peter Tscheliesnig
Hartmut Vallen (Germany) - Chair
Conference Organizing Committee
Peter Tscheliesnig - Conference Host (Austria)