advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...

Advanced Building Skins
Because the people inside do not experience the deformation of the outer skin, there is no need for low
deformation limitations. This results in a higher efficiency of material governed by strength.
Figure 18: Deformation of external skin loaded [1] Figure 19: Outer skin deforms because of wind
loading, but inner skin hardly moves [1]
Because of the independent behaviour of the external and internal skin and the air movement in the
cleft the varying external loading has limited influence on the loading of the internal skin. The
pneumatic arches, supporting the internal skin, therefore are mostly loaded with permanent equal
divided loading: self weight, internal skin, the water tubes and the air pressure in the cleft. When the
differentiation of the loading pattern on an arch structure is limited, the arch can be designed as an
optimum compression arch with limited bending moments. This will make it possible to design
slender and mostly axial loaded pneumatic arches.
6 Conclusion
The façade can play an important role in building physics, but also structurally on how a building
reacts on a wind loading.
A second skin façade is discussed that is flexible connected to the building, symbolised as a massspring-damper
system. Flexible structures reduce the internal forces and reaction forces in case of a
short impact. But with a harmonic loading they can increase to a level higher than in a static situation.
Wind is a constant changing dynamic load with both gusts and harmonic fluctuations. The active
control of the spring and damper stiffness connecting the façade to the building, can give us better
control over the force development but can also give us the possibility to optimize wind energy
absorption.
To further reduce the loading on a building two designs are shown in which the second skin is fully
independent of the main building. Between a fully fixed second skin façade and the fully independent
façade a large variety of interactive design options between the façade and the building are possible
optimizing forces and energy absorption.
7 References
[1] Habraken, A.P.H.W., “Natrix barrier of silence”. Competition entry: Creating a Sound Barrier for
Amsterdam Airport Schiphol, 2008.
[2] Schiphol brochure design contest: “Create a Barrier of silence”, 2008
[3] Habraken, A.P.H.W., “De Constructieve Tweedehuid”, TU/e Eindhoven University of Technology, 10-07-
2003
[4] Picture: ‘City In Antarctica’, website www.loop.ph
[5] Picture: ‘Frequency of Wind Speed Occurrence ‘, website www.windenergy.nl
[6] C.W. Newberry Alit. IVnd Kjeaton, “Windloading Handbook; Building Research Establishment Report”
[7] Stellingwerff, D.A. and Hajji, B., “ Tweede huidfacade – Scheiding van dynamische belasting tussen gevel
en binnenconstructie”, masterproject Eindhoven University of Technology, Faculty of Building and
Architecture, Eindhoven, The Netherlands, 2012
[8] Bosma, S., “Flexibility in structural design inspired by compliance in nature”, masterproject Eindhoven
University of Technology, Faculty of Building and Architecture, Eindhoven, The Netherlands, 2012
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