Optimization of Designs and Construction Methods

The Support Structure Test Center for onshore and offshore wind turbines is currently under construction in Hannover-Marienwerder and is expected to be available for industry and research from June 2014. The test center is suitable for all types of support structures and offers two large-scale test facilities:

Foundation test pit: exploration and evaluation of support and foundation structures and affiliated construction methods for their offshore installation in 1:10 scale and larger.

Span: large-scale (1:9 to 1:5) support structures or large components can be clamped in with the aim of examining their fatigue behavior using multi-axial loading.

In order to be able to fulfill preliminary tasks and accompanying examinations, the test center has special laboratories for steel, concrete, composites and geotechnical studies. Furthermore it is equipped with an autoclave, a resonance test machine and a salt water spray chamber with ocean climate.

The experimental research facilities of the Support Structure Test Center contribute to the optimization of onshore and offshore wind turbines. By using support structure designs which are technically reliable and economically efficient, plant availability and thus cost efficiency is achieved. Partners from industry and research are supported by an experienced team of structural engineers, process engineers, material developers and geologists.

More Output through Greater Availability

The Support Structure Test Center is offering:

• Large-scale tests:
  Cyclic load tests on support and foundation structures and their components can be performed on a large scale, i.e. up to a 1:5 scale. Test conditions are clearly defined and reproducible and thus allow to answer complex questions.
• Development and validation:
  Wind turbines can be developed and simulation models validated, using structure models, numeric calculations and large-scale experiments.
• Increasing lifetime:
  Damage occurrence at steel or concrete support structures can be discovered in the tests. In this way, it is possible to take measures in time to prolong the life of the wind turbine.
• Time lapse tests:
  The test center makes it possible to simulate the structure’s dynamic and fatigue behavior under the long-term cyclic influence of waves, wind and plant operation in “time lapse”, i.e. tests lasting three to four months. This makes the tests very economic and efficient.
• Better cost efficiency:
  It is possible to apply a predefined load for the support and foundation structures up to extreme load. Those load experiments can be performed even for a very high amount of load cycles. With the help of these tests, system reserves can be determined and the structural design can be adapted accordingly. Constructing more slender structures while maintaining structural safety and reliability enables savings on materials and logistics.
• Material tests:
  New materials and material combinations can be tried out at the test center, for example for the design of new types of structure connections in hybrid construction, particularly in steel and concrete.
• New constuction methods:
  The ramming of steel foundation piles, especially with large diameters, is still associated with high noise emissions. More environmentally friendly construction methods can be developed and tested at the center.
• Ground evaluation:
  The permanent cyclic load on support structures or extreme loads can reduce the sustainability of a sandy subsoil or lead to shifting and/or misalignment of foundations. At the test center, it is possible to examine and evaluate the mechanical ground behavior and the interactions between ground and construction under long-term cyclic loads.