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.
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| ASCE members at a special event at Wessex Institute |
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.
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| ASCE members |
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.
