A meeting was arranged at the Wessex Institute Campus in Ashurst Lodge, to bring together the ASCE members in the UK and let them know about the recent developments of the Society in the USA, as well as listen to an interesting technical talk about bridge design.
The meeting was opened by Prof Carlos A Brebbia, President of the ASCE/UK Group, who described the work of Wessex Institute. Carlos pointed out that WIT’s main function is the dissemination of knowledge and hence the Institute, rather than being in competition with other academic bodies, collaborates with many of them throughout the world.
The WIT activities are carried out through supporting industry with advanced consulting and software tools. Another important role is the publication of specialist literature and maintaining a large Open Access database, from which papers can be downloaded for free. A further function of WIT is the organisation of technical conferences in different locations, in collaboration with other research institutions and universities.
Carlos finished his introductory remarks by thanking everybody for coming to the meeting which he hoped will be followed by similar seminars in the future. He also expressed the gratitude of ASCE/UK for the presence of the two speakers at the meeting, ie Prof Alex Cheng, from the USA, and Prof Santiago Hernandez from Spain.
Prof Alex Cheng is a Professor of Civil Engineering at the University of Mississippi and currently Dean of Engineering at the same School. He has a distinguished academic and research career, starting with his PhD at Cornell University, where he also taught for some time before taking a position at Columbia University, followed by one at the University of Delaware.
He is renowned in the field of computational mechanics and serves now as the Editor in Chief of the International Journal of Engineering Analyses with Boundary Elements. Alex is also a member of the Board of Directors of WIT and collaborates with the Institute as an Adjunct Professor.
He has been very active at ASCE where he was past president of the Engineering Mechanics Institute. Amongst his many honours and awards he has been the recipient of the Walter L Huber, Civil Engineering Research Prize.
Alex started by paying tribute to the long Civil Engineering tradition in the UK. Civil Engineering can be dated to the first use of that name by Smeaton even before the Institute of Civil Engineers started. It was much later that the ASCE was created.
Alex also mentioned that his own University of Mississippi at Oxford, founded in 1842, followed the English model. One of the first founding professors, John Millington (1779-1868) was the author of The Elements of Civil Engineering, the first handbook of the profession.
Alex explained the importance of the ASCE not only in the USA but also throughout the world. It has developed a series of Institutes which carry out activities in many different countries. It is still mainly a professional association in spite of its research interests.
Alex has been involved with the Engineering Mechanics Institute and described their technical support work which is very varied as it covers many different fields. Some of these topics eventually gave rise to new groups in their own right.
The Institute’s interests range from computational methods to new materials and nanotechnology. The topic of eco-friendly materials is very much in the agenda of the Institute. The Institute has produced a series of successful reports dealing with civil engineering infrastructure problems, including the state of buildings, sewage systems and many other types of infrastructure.
The ASCE reports are taken into consideration by the USA Government. They are highlighted through the work of lobbyists in Washington. This is an important function of ASCE and one of the main reasons for some experts to join the Society.
After Alex’s address, Carlos introduced Prof Santiago Hernandez, F.A.S.C.E. Santiago is a Professor of Civil Engineering at the University of A Coruña, Spain. Santiago also has a long and distinguished research career. One of his main research areas is the analysis and design of bridges. He has written a book on ‘Bridge Aeroelasticity: Sensitivity Analysis and Optimal Design’, recently published by WIT Press, 2011, ISBN: 978-1-84564-056-9.
Santiago has received a most important Award, ie the Distinguished Achievements Medal of Civil Engineers in Spain. The award given once a year is highly prestigious. Santiago is an Adjunct Professor, as well as Member of the Board of Directors, of the Wessex Institute. He has collaborated with WIT for a long time, including in the organisation of courses and international conferences.
During his talk Santiago showed a series of interesting projects which were analysed by his Group. He also described his laboratory facilities for testing bridge spans to obtain their aeroelastic properties. Currently, there are – Santiago said – a number of interesting projects all around the world, many of them setting new records in terms of span length and new materials. It took longer than 20 years after the famous Tacoma Bridge design for the profession to realise the importance of flutter. The earlier understanding of the problem, as postulated by von Karman, produced what is now called von Karman Vortex Street, without pointing out the phenomenon of flutter.
Physical models of bridges are expensive to construct and run. They do not always produce the best results due to problems of scale. Frequent design changes along the way make physical models difficult to use as they require constant modification.
Computational Fluid Dynamics software can also be used to understand the structure-fluid interactions such as the behaviour of the deck under wind. They are not reliable for problems such as flutter, at the moment.
Because of that Santiago’s group proposed to combine experimental and computational methods. The test is carried out using only a section of the deck to obtain the necessary coefficients to define that section as an element in a computer code. The test is carried out in a comparatively small aerodynamic wind tunnel.
Flutter is the cancellation of the damping of the structure for a given wind speed. As the speed of the wind increases the damping reduces, as was the case with the Tacoma Narrows Bridge. Because of that it is necessary to compute the response of the bridge for different wind speeds and see when the damping becomes zero, obtaining in this way the higher wind speed that the bridge can undergo.
The advantage of Santiago’s approach is to require reduced laboratory facilities; testing is less expensive, costs are not related to bridge lengths, and the designer is given a better representation of flutter.
Both talks gave rise to a period of discussion with numerous questions and exchange of ideas amongst the participants.
The seminar was followed by a tour of the Wessex Institute premises, led by Carlos, who explained the work of the different departments.
Finally the members were offered a light lunch before departing.
The meeting was most successful and it is expected to lead to further collaboration amongst the participants.