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2.2 AA Membrane Canopy, 2007

 AA Membrane Canopy 2007 – Emergent Technologies and Design Programme 0607 @ Architectural Association, London

AA Membrane CanopyBuilding with membranes is emerging from the shadow of the early pioneering achievements. Several decades of practical experience have led to a technology that is future oriented and that deserves to be more widely established…
Klaus-Michael Koch, Membrane Structures, Prestel, 2004

The canopy for the roof terrace of the Architectural Association in London was designed by the Emergent and Technologies and Design Programme in collaboration with Buro Happold, one of London’s leading engineering firms that has been engaged in many high profile projects such as the new roof of the British Museum. The design is a component based membrane system. The design team of EmTech and the engineering team of Buro Happold met on a daily basis integrating design and engineering consideration towards a multi-performative membrane assembly.

The canopy was developed using Generative Components, a new software package developed by Bentley Systems, Inc. for associative parametric modelling. The underlying logic of parametric design can be understood as an alternative design method, in which the geometric rigour of parametric modelling can be deployed to integrate manufacturing constraints, assembly logics and material characteristics in the definition of simple components, and then to proliferate the components into larger systems and assemblies. This approach employs the exploration of parametric variables to understand the behaviour of such a system and then uses this understanding to strategise the system’s response to environmental conditions and external forces.

The role of digital models was thus not to derive a particular gestalt defined by a series of coordinates, but instead a range of possible formations that is coherent with the processes of fabrication and assembly and maintains behavioural characteristics. The morphology of material systems is defined not only through a set of points but also through the relations of proximity and contiguity of these points. In Euclidean geometry the relation between points is expressed as fixed length and distances that stipulate how far apart points are in relation to one another. Euclidean geometry operates in ‘metric spaces’ based on concepts such as length, area and volume. However, in topological space distances expressed in length cannot characterize proximity as the length does not remain fixed. Such topologies can be stretched or scaled without changing the characteristics of its defining points. In this way, significant changes in the design that are accommodated by the parametric definition are possible until the late in the design process.

The notion of ‘component’ needs also to be expanded: it integrates the possibilities and limits of making, and the self-forming tendencies and constraints of materials. Furthermore, it anticipates the processes of assembly and is defined as part of a component collective, opening up the possibility for building up a larger system. Another key development is that this component’s geometric aspects can be defined by the transformations under which they remain invariant, meaning that its possible geometric associations can be strategised according to characteristics of Euclidean geometry, affine geometry, projective geometry or topology. A critical task for the designer, then, is the negotiation between metric precision and topological exactitude. Fundamental to this approach presented is the understanding of a component system as a population of individual components. The transformative potential of the system is enabled by the differentiation of its sub-locations through the abilities of an open parametric components and component systems that serve to modulate environmental conditions.

The design results in a differentiated component system with every membrane and every steel member having different dimensions. The membranes are to some extend structural elements, taking on tensile loads, particular in the edge cables of the membranes, whereas the steel members take compressive forces. The structure as a whole works as a cantilevering roof that is supported by three columns. The differentiated component logic of the system allows for spatial and environmental variations of the canopy, such as varying degrees of sun-shading, rain-protection and airflow. These effects are mainly modulated by the degrees of openness or porosity of the individual components. They were tested using specific simulation software. On a much smaller scale, the component membrane introduces a shingling system that allows for the membranes to overlap and thus runs off rainwater in spite of the many openings. Computer fluid dynamics analysis served to simulate airflow that impacts upon and results from the membrane assembly. It was important to reduce the wind-load on the assembly so that it did not act like a big sail. In addition it was necessary not to accelerate the airflow so much that inhabiting the space under the membrane would become uncomfortable.

The eventual digital model was translated into manufacturing instructions and excels sheets with the dimensional specifications, allowing for the membranes to be laser-cut to size. The integration of digital modelling and manufacturing constraints enabled relatively complex and varied geometries to be realized without becoming either too costly or time-consuming to manufacture.

 
PROJECT CREDITS

Project Coordination
Michael Hensel, Michael Weinstock, Achim Menges

Digital Modelling Coordination: Omid Kamvari Moghaddam
Structure Coordination: Daniel Caserta Segraves
Material and Fabrication Coordination: Bulut Cebeci
PR and Documentation Coordination: Karola Dierichs

Design and Construction:
Irina Bardakhanova, Maria Bessa, Arielle Blonder-Afek, Bulut Cebeci, Yi Wen Chen, Karola Dierichs, Christina Doumpioti, Andres Harris Aguirre, Omid Kamvari Moghaddam, Sreedhar Mallemadugula, Cyril Owen Manyara, Akanksha Mittal, Matteo Noto, Onur Suraka Ozkaya, Elke Pedal Baertl, Gabriel Sanchiz Garin, Daniel Caserta Segraves, Defne Sunguroğlu, Manja Van de Worp, Christy Widjaja

Structural Engineering – Buro Happold
Project Coordination: Mike Cook, Wolf Mangelsdorf, Toby Ronalds
Engineering Team: Kevin Berry, Jamie Goggins, Chris Hulmes, Jean Pierre Kim, Marissa Kretsch, Tom Makin, Ivan Muscat, Greg Phillips, Toby Ronalds, Ricardo Sequeira

Software Collaboration:
Robert Aish, Director Bentley Research, Generative Components, Bentley Systems Inc.

Membrane Technology Consultants: WG Lucas and Son

Membrane Cutting and Labelling: Automated Cutting Services Ltd

Membrane Sewing: London College of Fashion

Steel Nickel Plating: Fox Plating

Sponsors:
AA Workshop, Bentley Systems Inc., Kamkav Construction Ltd., MPanel Support Team, Ocean North, Online Reprographics

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