Fraunhofer-Institut IWES, Bremerhaven
Technical / General information:
ETFE facade, single-plyDimensions / sqm:
Fraunhofer GesellschaftMembrane Assembly
: May 2012
The Fraunhofer-Gesellschaft zur Förderung der angewandten Foschung e.V. (registered association for the promotion of applied research) erected a multistory engineering building in Bremerhaven offering workshop and office facilities for the institute. The development and extension of the business area “wind energy” made it necessary to improve the working conditions for the research projects by supplying additional office space and test facilities. According to the intended purpose “research in wind energy” the building acts as a visible sign with an appealing, technically demanding curtain wall.
The wall structure is a mixture of a rigid, form-giving and load carrying steel sub-structure with glass panels, and flexible single-layer ETFE sheets which are pre-tensioned by cables. The curtain wall is connected to the massive building by 380 steel strut brackets welded onto plates fixed at the building. Floor-wise, the struts, having a horizontal distance pattern of 1,17 m, have different gaps between the traverse stations of the concrete construction and the steel rings, leading consequently to different lengths. Bent steel profiles (circular girders) follow the outline of the building at each floor, forming the horizontal connection line of the ETFE sheets and the glass panels. The ETFE bays 1 – 4 each have a wind suction cable connected to the front profiles. The upmost ETFE bay has two wind suction cables additionally connected positively to the massive wall in 4 points.
The complicated installation conditions due to the direct vicinity of the sea required special attention. During the installation works permanently changing weather conditions prevailed with different wind speeds up to wind speed 6. This led to a complicated handling of the large ETFE bays (ca. 50,00 x 1,50 m per bay) requesting a sophisticated logistic preparation for an installation period of about 2 weeks, including all back-work.