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LB Engineering GbR Chausseestrasse 8 info@LB-e.de Dipl.-Ing. Christoph Lederer Dipl.-Ing. Steffen Bruck

10115 Berlin www.LB-E.de

Tel.: +49 30 24008988Fax: +49 30 24008985

Berlin 05.12.2007

„Can safety and aesthetic be combined for events without compromises?”

Maximum safety for the publicity of events is one of the most important goals for organizers and tent manufacturers. Especially considering the ever increasing strong winds and other extreme weathers, this will become more even important. In the area of wind loads the introduction of the new DIN norm will have great consequences on all tent systems.

This is why ZENDOME, the Berlin manufacturer of geodesic space, has decided to have its tent constructions tested for wind loads by LB Engineering. By means of the numerical streaming simulation the wind impact and forces on the geodesic structures where calculated and evaluated considering the new EU norm for wind loads for buildings.

In the following interview managing director and engineer Christoph Lederer presents the numerical test for wind loads on the ZENDOME.

Mr Lederer, what kind of experience has LB Engineering had with temporary buildings and other mobile architecture for the event business? Our services are mostly required for large projects because our competence in the area of streamline mechanics stretches over a vast spectrum, ranging from numerical stream simulation to metrological registration of streaming parameters. This way for example, we calculated the wind loads on the moving roof structure of the Venezuelan “La Flor de Venezuela” pavilion at the EXPO in 2000.

Are your results put into practice? The complex roof construction of the Venezuela Pavilion is opened by means of a hydraulic system according to changing weather and thus is subject to strong wind loads. The calculations prove the safety of the construction even at its new location in Venezuela where it will be reopened at the beginning of 2008.

Concerning geodesic structures you have exemplarily tested the ZENDOME.150M. Which requirements where thus defined? It was very enjoyable to test this interesting structure. In cooperation with a structural engineering company we defined the forces and did not spare the system anything. And we have already taken the new Euro norms into account. During the strong wind weather of the last years the ZENDOME has already proven the safety of its structure. In order to provide their guests with a maximum of security our clients now want to have this experience proven by streaming simulations. In addition to the regular testing they have now requested an impartial analysis by our company.

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LB Engineering GbR Chausseestrasse 8 info@LB-e.de Dipl.-Ing. Christoph Lederer Dipl.-Ing. Steffen Bruck

10115 Berlin www.LB-E.de

Tel.: +49 30 24008988Fax: +49 30 24008985

Can you explain the testing design in two sentences? The wind loads on the ZENDOME where calculated via the numerical simulation based on wind speeds of 30m/s 10m above ground. With the results of these streaming calculations the load spread on the membrane of the ZENDOME can be determined which then can be translated into the resulting forces on the ZENDOME. This then is the basis for examining the anchoring and additional weights.

You have reached the conclusion that the structure will be lifted from the ground with 40 tons pulling force thus making the geodesic dome similar to an aeroplane wing. How are these forces received? Because of the round form of geodesic domes the wind is accelerated to up to 220 km/h leading to strong forces on the suction side – just as found with aeroplane wings. Our testing shows that the ZENDOME also meets the requirements resulting from the EN 1991 -1-4 and the new adapted to the Eurocode 1 DIN 1055-4 even in rural areas where the strongest wind forces are found. ZENDOME meets these high forces with according anchoring and correct additional weights.

Are there many companies in the business of temporary buildings that have their systems tested? To be honest, I cannot say for sure but I would not imagine so. Even though the last year with its strong wind weathers has seen several structures taking off. Of course the high end processing of the geodesic domes and other mobile buildings alone does not guarantee the safe standing – of course the given additional weights are also an important part of the safety of these kinds of structures.

If you take a closer look at the data on the market, what is so special with this system? There are several providers of systems with which geodesic structures can be realized. The result of our testing has confirmed our impression that ZENDOME follows a very strict quality policy and puts the safety of their customers first at all times. In addition to all this, the ZENDOME just looks wonderful.

Mr Lederer, we thank you fort his interview!

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LB Engineering GbR Chausseestrasse 8 info@LB-e.de Dipl.-Ing. Christoph Lederer Dipl.-Ing. Steffen Bruck

10115 Berlin www.LB-E.de

Tel.: +49 30 24008988Fax: +49 30 24008985

Illustration of the streaming calculation results in form of particle paths around the ZENDOME.150M

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LB Engineering GbR Chausseestrasse 8 info@LB-e.de Dipl.-Ing. Christoph Lederer Dipl.-Ing. Steffen Bruck

10115 Berlin www.LB-E.de

Tel.: +49 30 24008988Fax: +49 30 24008985

Contures of the speed spreading above the pavilion “La Flor de Venezuela” at its location Barquisimeto, Venezuela (calculated by numerical streaming simulation, LB Engineering)

Speed vectors above the pavilion “La Flor de Venezuela” at its location Barquisimeto, Venezuela (calculated by numerical streaming simulation, LB Engineering)