Environmental Engineering Reference
In-Depth Information
The ongoing development of ever more powerful wind turbines plus additional
requirements for the design and construction of their offshore foundation structures
exceeds the actual experience gained so far in the various disciplines concerned. Wind
turbines represent structures subjected to highly dynamic loading patterns. The load
cycles of onshore installations can reach N
10
9
, but those of offshore installations can
¼
10
8
due to the sea conditions. Therefore,
for the design of loadbearing structures, fatigue effects - and not just maximum loads -
are extremely important. This can lead, in particular, to multi-axial stress states arising
in the connections and joints of concrete and hybrid structures (see Sections 3.6 and
4.9), which have considerable effects on the fatigue strength and so far have not been
addressed in the applicable design codes.
On the whole, there is still a great need for further research in the various disciplines
involved in the planning, design and construction of wind turbines. It was for this
up at the Carl von Ossietzky University of Oldenburg and the Leibniz University of
Hannover in 2003, thus enabling engineers from different disciplines to work together
on research into wind energy. Supported by the Lower Saxony Ministry of Science and
Culture, the objective of the centre is to pool research activities. Construction
technology research into offshore wind turbines began at the University of Hannover
sponsored by the Federal Ministry for the Environment, Nature Conservation and
Nuclear Safety. These research activities are divided into three areas: actions due to
wind and waves, design of loadbearing structures (including foundations) and environ-
mental technology aspects.
GIGAWIND alpha ventus
is a project associated with the
RAVE
(
be exposed to further load cycles of up to N
¼
ntus
) research initiative and therefore has access to the
extensive programme of measurements carried out at the Alpha Ventus test site,
Germany's first offshore wind farm. At European level, the University of Hannover
here is to promote research and development and to train PhD students in the field of
wind energy in various European countries.
The basic concepts for the planning, design, analysis and construction of tower
structures, focusing on wind turbines especially, will be explored in the next chapters.
Many aspects of these basic concepts also apply to the structural and constructional
requirements of other tower-type structures, for example
- telecommunications towers
- radar towers and lighthouses in shipping lanes
- antenna support structures and masts for mobile telephone networks
- chimneys
For more information on these structures please refer to
Beton-Kalender 2006 Teil 1
,
pp. 103-223 [8].
R
esearch at
A
lpha
Ve
