2010-3 general survey of deploy able structures with articulated bars

Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2010, Shanghai Spatial Structures – Permanent and Temporary

November 8-12 2010, Shanghai, China

General survey of deployable structures with articulated bars.

Escrig1*, Félix. Sánchez, José 2 1*Professor of Architecture in the University of Seville.

Avda. Reina Mercedes 2 41012. Seville. Spain. [email protected] www.performance-starbooks.com

2 Professor of Architecture in the University of Seville [email protected]

Abstract The paper deals with the state of the art of deployable structures based in the behaviour of groups of bars connected between them at their ends but also at intermediate points. There are several systems accepted as capable of configuring different dynamic positions statically determined. We introduce a general view of some of the most used systems that we identify as umbrellas, bundles, scissors, rings, polyhedron, flat panels and curved bars systems. Keywords: deployable structures, umbrellas, scissors, foldable polyhedra, foldable rings, articulated bars. 1 Introduction

There are structures that are based on the mobility of ensembles of bars united by means of articulated joints (Figures 1 and 2).

Fig. 1: Arp Player Summer. Fig. 2: Senefer tomb of Amenofis II Fig. 3: Hunter chair They pass from an initial folded very compact and another one extended on a plane or on a curved surface. The system of covering, when existing, will usually be flexible (Figure 3). Only exceptionally it will be rigid. The fundamental systems are: Umbrellas, bundles, rings, polyhedra, planes and coupled arches.



2 Umbrellas.

They were the most ancient foldable structures and they are documented in Middle East bas-reliefs and also in a lot of drawings (Figure 5). They were usually conceived in small pieces but for great size even Leonardo planned a proposal carefully represented with the probable intention of being built.

Fig. 4: Black obelisk of king Salmanasar III. Fig. 5: Assurbanipal king stone (British Museum.) Fig. 6: Madrid I Notebook by Leonardo da Vinci

Fig. 7: Convertible Umbrellas at the Bundesgartenschau, Cologne, Germany 1971 (together with B. Rasch, H. Isler.)



Nowadays the main umbrella designers come from the Frei Otto School and they planned to place the flexible roof below the foldable structure with difference respect to traditional umbrellas (Figure 7). Bodo Rasch is the designer who proposed the most developed constructions and they are his famous great umbrellas for covering mosques (Figure 8 and 9) and other mobile application powered with photovoltaic energy (Figure 10).

Fig. 8: Convertible Umbrellas in the inner court of the Prophet's Mosque in Medina, Saudi Arabia, 1971 (Bodo Rasch )

Fig. 9: Umbrella design by Frei Otto

Fig. 10: (Jurgen Bradatsch) Stage umbrellas for a concert tour of the group Pink Floyd, 1978 (together with B. Rasch and Office Happold



Fig. 9: Solar convertible Umbrellas 5x5 m. Makkah and Obhur, Saudi Arabia.

3. Bundles.

The word bundle means here that our structure is compact with all its elements aligned in a parcel when folded and which deploys in two directions as a spider web. We can distinguish between three main types: With joints only at the end of bars (Figure 10), with lockable joints in the intermediate points and with intermediate joints with continuous bars.

Fig. 10 Flying Seedpod model by Buckmister Fuller in 1953



Looking for deployability, Buckmister Fuller patented several systems that, once deployed, were hardly foldable. These designs have been successfully used in aerospace applications because it is not necessary to recover space panels. The lockable meshes are included in this type.

Fig. 11. Models designed at the Surrey Laboratory of Space Structures 1985. In 1970 Emilio Pérez Piñero proposed an experimental design very awarded at his time and which took the attention of Candela and Fuller (Figures 12 and 13) . They encouraged the young architect to build at a full scale this kind of solution and the results where a few masterpieces which are shown in the figures 12 to 14 all of them realized with modulus of three bars.

Figure 12. Deployable dome winner the UIA Competition in 1961 by Emilio Pérez Piñero. It consisted in a itinerant theater.



Figure 13. Itinerant theater not built by Emilio Pérez Piñero.

Figure 14. Two layer dome by Emilio Pérez Piñero. With a solution of modulus composed of four bars he built an itinerant exhibition pavilion shown in the figure 15. Unfortunately the author was dead in a car crash in 1972 at 36 years old.



Figure 15. Itinerant exhibition pavilion made with modulus of four bars. 1964 Pérez Piñero based his designs in modulus of three or four bars instead of simple scissors that lead to more realizable solutions like shown in the figures 16 and 17.

Fig. 16. Leonardo lifting mechanism. Fig 17. War ladder made to scale walls.



The utility of this kind of scissor combination was understood very early as seen in the figure 17. In architecture the first proposals came from Escrig and Sánchez who built the Seville swimming Pool with spherical segments as shown in the figure 18.

Fig 19. San Pablo swimming pool in Seville in 1994. Arch. Escrig and Sanchez Fig. 18. 19th Century elevator. With posteriority a lot of designs with a lesser scale have been realized. The most interesting by Masao Saito (Figure 20) or Carlos Henrique Hernández in cilindrical surfaces (Figure 21) and Luis Sánchez Cuenca for spherical domes (Figure 22).



Fig. 20. Cylindrical deployable grid by Masao Saito 2005.

Fig. 21. Cylindrical deployable grid by Carlos Henrique Hernandez. Caracas. Venezuela 1990.

Fig. 22.Spherical Shell like by Luis Sánchez Cuenca. Gerona. Spain. 2007.



4. Rings. Bundles fold in a compact parcel in a central point and they are not useful to cover circular areas where it is preferable to fold the structure around the border. In this case we can also use scissor systems. The cleverest idea is the proposed by Chuck Hoberman in which the tree hinges of each piece of scissors are not aligned. Hoberman checked that it was possible to fold and extend the ensemble with practically no displacements al the exterior hinges (Figure 23) Other proposals based in the same idea are extraordinarily suggestive (Figure 24).

Fig.23. Iris dome at the MOMA NY. by Chuck Hoberman in the folding process.1991.

Fig. 24. Arch at the Winter Olimpics Salt Lake City 2002. Chuck Hoberman.



5. Polyhedra.

Blade mechanisms can also concentrate on spatial arrangements to create spongy bodies that expand from a central position. Hoberman sphere is the best known one of all around the world although the main application so far has only been a toy. Fig. 25. Deployable spherical toy by Chuck Hoberman. 1995.

Fig. 26. Expanding Geodesic Dome by Chuck Hoberman in New Jersey Liberty State Park. 1991.

Fig. 27. Deployable icosahedron by Escrig 1985.



6. Planes.

They are flat sets of pinned bars which mobility makes them take spatial configurations. Santiago Calatrava is one of the great masters of this type of solution, using it on large scale (Figures 28 and 29). But we have also precedents for this solution in the leonardo´s Notebooks in the figure 33 shown at the end of this paper.

Fig. 28. Foldig door for Ernsting Coestfeld-Letle store .Germany. Santiago Calatrava. 1983. Fif 29. Pfalzkeller Gallery in St. Gallen. Switzerland. Santiago Calatrava.1988. 7. Coupled arches. Another very special solution is to create blades with curved bars and multiple joints through a system like one shown in the figure 30 with interesting applications such as those described in figures 31 and 32.



Fig. 30. Coupled arch basic model by Felix Escrig. 1998.

Fig. 31. Mobile roof for a swimming pool with coupled arches spanning 20 m. by Escrig and Sánchez. 1999.

Fig. 32. Mobile roof for an auditory with coupled arches spanning 42 m. by Escrig and Sánchez. 1999.



8. Epilogue. The possibilities of deployment of the meshes of bars are huge and we have realized an overview of current achievements. However, theoretical studies go much further and hopefully many of them will turn into innovative proposals and applications. We have forgotten to mention many designers who have made significant progress in the field of the paragraphs exposed and we apologize for it. We have selected specific built examples and a longer version of this exhibition will be proposed in an extended version of this paper.

Fig 33. Flying machine by Leonardo da Vinci with mobile articulated arms References

[1] Candela F, Pérez Piñero E, Calatrava S, Escrig, F and Pérez Valcárcel J. Arquitectura Transformable. Textos de Arquitectura. Escuela de Arquitectura de Sevilla.1993. ISBN 84-600-8583-X.

[2] Escrig F. Sánchez J. Mobile and Rapidly assembled architecture. STAR Structural Architecture n1. University of Seville. 1996. ISSN

[3] Gantes Ch.J. Deployable structures. WIT Press ISBN: 978-1-85312-660-4 2001. [4] Pellegrino S. Deployable Structures”. Springer. 2001 ISBN 3-211.83685.3.

2010-3 general survey of deploy able structures with articulated bars

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