DEPLOYABLE STRUCTURES Collapsible Structure from a ruled surface
DEPLOYABLE STRUCTURES : Collapsible Structure from a ruled surface A Dissertation submitted for (MArch) Master of ARCHITECTURE RIBA PART II
By Margarita Vervele Canterbury School of Architecture Tutor: John Bell
CONTENTS
Introduction............................................
7
Making the “ring” & the “legs”................ 50
Significance of deployable structures.... 10
Final Model............................................ 52
Concepts of deployable structures........ 12
Conclusion............................................. 67
Hoberman’s deployable structure.......... 14
Bibliography........................................... 69
Scissors deployable structures.............. 16 NASA type cubic.................................... 18 Fast mast............................................... 20 Construction........................................... 22 Model 01................................................ 23 Model 02................................................ 25 Model 03................................................ 27 Model 04................................................ 35 Model 05................................................ 44
INTRODUCTION
TREE DIAGRAM
NASA TYPE CUBIC DEPLOYABLE BASED ON BENNET LINKAGES
Deployable Typologies
LATTICEWORK
TWO-WAY-FOLD TRUSSES
ROLLING BRIDGE
SCISSORS RADIAL EXPANSION/RETRACTION
RIGID-FOLDABLE THICK ORIGAMI
TRUSS STRUCTURE
RIGID ORIGAMI STRUCTURES WITH VACUUMATICS
ORIGAMI PAPER PLEAT
COMPOSITE RIGIDFOLDABLE CURVED ORIGAMI STRUCTURE
GENERATIVE TECHNIQUE
RIGID CENTRIFUGAL ANTENNA
SOLID SURFACE
DEPLOYABLE HINGED PLATES DEPLOYABLE ‘BLOB’ STRUCTURES
RIGID ORIGAMI BAG
PUSH BUTTON HOUSE 1
DEPLOYABLE TYPOLOGIES
WING FOLDING IN BEETLES THE GEOMETRY OF UNFOLDING TREE LEAVES
ANIMALS
NETS FABRICS INFLATABLES
PLANTS BIOMIMETICS STRUCTURAL COMPONENTS
ELASTIC KINEMATICS CONCEPTS FOR ADAPTIVE SHADING SYSTEMS
DEFORMABLE
FLEXIBLE
BENGT SJOSTROM STARLIGHT THEATRE
TENNIS COURT ENCLOSURE INFLATABLE AIR CELL STRUCTURES COMMONWEALTH AEROSTAT
STEMS FAST MAST
COMBINED
THREE-DIMENSIONAL DEPLOYABLE SCISSOR GRIDS DEPLOYABLE COVER FOR SAN PABLO SWIMMING POOL RETRACTABLE MEMBRANE SOUNDSFORMS SARA
FOUR-STAGE MAST EIGHT-STAGE MAST
Sourced from Adrover, E. R., 2015. Deployable Structures (Form + Technique)/ redrawn
AXI-SYMMETRIC REFLECTOR ANTENNA
With so many technological changes, there has been a significant change in archi-
figure of an example to show how deployable architecture works:
tectural designs too. With newer and advanced technologies, nowadays, deployable structures are prepared that can turn into a specific structure and can re- fold or return to normal shape for ease of accommodation. In order to explain what a deployable structure is, it is important to consider that it is a kind of structure that changes shape and correspondingly changes size as well. However, this concept of deployable structures is not a new one and all the human beings have known such deployable structures for years or probably from the time they were able to comprehend. Examples of the basic or very common deployaFigure 1: Deployable house (Weebly, 2015)
ble structures include umbrellas. Other than this, bi- stable structures, tensegrity structures, scissor like structures as well as some of the Origami shapes too are
This research helps to identify that deployable structures can be a beneficial
considered as deployable structures. Despite the fact that these all does not fall in
use as well as very important and prospective technology for the architectural
the category of architecture; but it is important to consider that these are the basic
industry. In order to discuss deployable architectural technology and structures,
deployable structures one could consider for understanding.
this paper will be sub- divided into different sections. The first section, after
Another very useful and interesting example of deployable structures can
introduction, will be about significance of deployable structures. In this section,
be seen in spacecraft where solar panels and solar cells are deployed. The pro-
importance or benefits of deployable structures with respect to their character-
cess through which solar panels and cells are deployed in a spacecraft includes
istics will be discussed. Followed by this, some of the basic concepts used in
deployable structures.
deployable structures will be discussed briefly as well.
Deployable structures categorized for space crafts and other machines
Also, benefits of folding and development of such transformable struc-
are basically categorized into 3 primary categories; where the 1st category is of
tures will be highlighted. Along with this, some of the different deployable struc-
articulated structure (in this category, structures slide on contact joints or fold on
tures as the architectural technology will be discussed such as the Hoberman’s
hinge/ pivot joints; however, this helps in locking of structure too) (Adrover, 2015).
structures and scissors like structures. Furthermore, different deployable struc-
The second category is of on- orbit structures where device or structure is me-
tures such as NASA type cubic and fast mast will also be discussed. Lastly, I will
chanically joined/ developed in space. Lastly, the third category of space based
describe how I developed my own deployable structure from a ruled surface. At
deployable structures is high strain structures where the structure is developed
the end a conclusion will be included that will provide summary of findings from
such that it flexes between one configuration and another easily. Following is a
this research.
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01
SIGNIFICANCE OF DEPLOYABLE STRUCTURES
In this fast paced world with so many technological advancements, it should not
Figure 2: Hoberman Geodesic Domes (Hoberman, 2011)
be neglected that people migrate or change their locations with respect to feasibility for employment opportunity as well as for other reasons too. For this purpose, architectural designs and structures are quite beneficial since they help the owner to move around easily. Folding and transformation helps the owner of product to change its form whenever in need. Along with this, folding also helps the user to change the purpose of plain sheet of paper for which it may be used. Moreover, with the help of unfolding the same folded or transformed structure, it is clearly identified that how the structure was developed; in this way, it can be replicated multiple times as well as on different scales. A morphogenetic solution can be employed through folding a system or design that can be made on a sheet of paper. This sheet of paper, then, can be folded and transformed into inhabitable structure. Along with this, since the structure is folding and transformable, cost efficiency and ease of fabrication will be reduced; this in turn will help to design systems or structures that can be built through low cost materials. These structures, thus, can be used for development of accommodations aesthetically and programmatically.
In light of this immense benefit that deployable architecture can provide, it is important to note that deployable architecture and structures can be easily used and provided as a means of accommodation facility in areas that have been hit by tsunamis and earth quakes. With the help of deployable and transformable structures, a transitional shelter may be provided to devastated communities in time of crisis management. In this way, deployable architecture can be a means of shelter for people who have lost their belongings due to natural disasters and other calamities.
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02
CONCEPTS OF DEPLOYABLE STRUCTURES
Deployable structures are based on three basic concepts. Of the three concepts,
In doing so, continuous analysis and review, errors that are usually left
two are genetic and new ones that are based on foldable cylinders and solid sur-
out previously are removed and new fold pattern is generated that is error free.
face deployable reflector. On the other hand, the third concept is an old one where
Also, with the help of this step, different ways are suggested that shows how a
a membrane, extended after analysis, is folded. According to the new concepts
concept could be extended further on. Another example of deployable structure
of deployable structures, foldable cylinders can transform into a stack of plates
is a solid surface deployable antenna. With the help of this antenna and its new
and are triangulated in shape. These cylinders fold in axially and transform into a
method of folding, a new wrapping method or fold pattern is identified.
compact structure.
Moreover, this antenna and its new folding method helped to understand
In the concept of foldable cylinders, a geometric approach is also intro-
that size can be considerably reduced in case of folding and there is no further
duced that provides insights about how the structure can be folded easily. On the
complex mechanical components required to do so. A new technique is usual-
other hand, folding is also analysed and computed to know how the experiments
ly implied in antenna’s model where rigid body displacements are represented
are taken of or what behaviour is shown by the structure. It has been identified that
through dual quaternions. The same design of antenna can further be optimized in
numerous cylinders have developed and experimented. The very first one was
order to remove any sort of deformation. The following figure shows a deployable
developed by wrapping a membrane around a central hub in 1960’s. However,
antenna:
sometime ago, this process has been considered to be a folding process of a space sail. With continuous conceptual analysis and review, new folding patterns are generated easily. The following figure shows a foldable cylinder:
Figure 3: Deployable cylinders (University-of-Surrey, 2016)
Figure 4: Deployable antenna (JAEA, 2008)
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03
HOBERMAN’S DEPLOYABLE STRUCTURE
First of all, to understand what Hoberman’s deployable structures are, it is im-
A number of exhibitions have been conducted that exhibited work of Hoberman
portant to note that Hoberman is a founder of Hoberman Associates. Hoberman
and its associates such as the one which was held in the Museum of Modern Art
associates is well known for the production of various products such as deploya-
in New York. One of the commissioned installation of Hoberman’s associates,
ble shelters, consumer products, as well as some space structures. A well- known
known as Emergent Surface, was also exhibited in the ‘Design and the Elastic
example of Hoberman’s structures include a transformable LED Screen used for
Mind’.
the U2 360 degrees world tour as a primary stage element (James, 2008). Along
Conversely, there have been so many developments and a number of structures
with this. Hoberman’s Arch in Salt Lake City was installed for the Winter Olympic
have been developed by Hoberman’s associates. According to Chuck Hoberman,
Games as a centerpiece. Following is the figure of Hoberman’s Arch:
unfolding architecture can be defined as an object that can be considered as an identical mechanism as well as structure. He also emphasized that such innovations could help in transfer of forces and motion in a controlled manner, where any secondary support systems will not be required.
Furthermore, Hoberman also posits that development of structures
through repetitive pleating of single sheet can help to transform between two states of a deployable structure; active state and dormant state. The active state refers to the structural configuration for which it has been developed and the dormant state refers to one that is a compact bundle. The system developed acts as a mechanism, developed through different matrix of fold, and allow such surface structures to behave like some kind of rigid and hinged plates.
Figure 5: Hoberman’s Arch (W, 2016)
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04
SCISSORS DEPLOYABLE STRUCTURES
With the increased need of light weight and kinetic structures, scissors like structure found a way into deployable architecture. A good example of scissors structure is the Hoberman’s sphere, an isokinetic structure. The structure is much like the geodesic dome that can fold and become a fraction of its normal size. This is accomplished with the help of joint’s action that act like scissors. The same structure is also available for children in colourful plastics where different sizes of the sphere can be seen. The actual design developed by Hoberman and associates can expand to a range of 15 centimetres, which is approximately 5.9 inches, in diameter and over as well to 30 inches or 76 centimetres (Pellegrino & Guest, 2000).
Deployable architecture based on scissors action are of great interest.
The Hoberman sphere is made up of six large circles. Each of the circle corresponds to an edge of icosidodecahedron. The sphere can easily unfold and fold with the help of certain members that fold and unfold. This is usually accomplished through the use of cable that are fed out in larger models. To date, the largest
Figure 6 : Hoberman’s sphere is AHHA Science Center (Hoberman, 2011)
sphere is located in the AHHA Science Center situated in Estonia (Tartu). The fully expanded sphere is about 5.9 meters in diameter or 19 ft. wide. The sphere weighs around three hundred and forty kilograms and is suspended above the Center’s Science Court. The sphere is constructed with aircraft grade aluminium. The sphere changes between the two states, collapsed and expanded, constantly through a control system along with lighting, music and some special effects. Following is a figure that shows the Hoberman’s sphere is AHHA Science Center:
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05
NASA TYPE CUBIC
For the development of NASA type cubic deployable structure, the developers considered symmetry as a basis for geometrical and morphological development. Different types of NASA type cubic deployable structures have been developed; namely, NASA PACTRUSS, X- BEAM and the STAC- BEAM. As per the structure of NASA PACTRUSS, it was seen that it is a lightweight structure. This structure was particularly used in different deployable structures such as deployable reflectors and antenna (Britt & Lalvani, 2014).
On the other hand, X- BEAM and STAC- BEAM, both, are considered
to be beneficial for as extendable support structures. These support structures are used to support platforms of solar concentrators and phased arrays. The researchers while working on the development of NASA type cubic deployable structures found that slight changes in the geometrical arrangements of STACBEAM can result in the formation of new structure, which is geometrically like the original piece but shows some different geometry in deployment. Following in a figure of NASA type cubic deployable structures where different shapes or possible geometrical arrangements are shown:
Figure 7 : NASA type cubic deployable structure (Britt & Lalvani, 2014)
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06
FAST MAST
Ever since the developments of deployable technology is the field of architecture, there has been an increased need to reduce weight of the structures. For this purpose, different experiments have been conducted and it has been found that extra bracing members can do the job and thus should be added in the structure. Along with this, the constraints added by bracing members can help to figure out different facts about deployable structures. To understand this scenario, a deployable structure developed by AEC- able Engineering in California known as the Folding Articulated Square Truss Mast (FAST Mast) can be considered (Pellegrino, 2014).
This structure of FAST Mast includes square frames that have hinge
axes directly parallel to them. Along with this, two pairs of cross bracing cables are also places on each face of the cube. It should be noted that half of the cables become limped while the structure folds and on the other hand, all the slacks and cables are taut when the structure is in complete open or deployed form. The following figure shows how the FAST Mast is expanded or collapsed and how cables as well as hinge axes help in doing so (in the transition phase) (Pellegrino, 2014):
Figure 8: Figure: Fast Mast (Pellegrino, 2014)
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07
CONSTRUCTION DEPLOYABLE STRUCTURES: COLLAPSIBLE STRUCTURE FROM A RULLED SURFACE • • • • • • •
Model Development 01 Model Development 02 Model Development 03 Model Development 04 Model Development 05 Making the ring & the “legs” Final Model
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.1
MODEL DEVELOPMENT 01
ERROR
The pivot point of the connection should be horizontal and facing the “ring� structure. The model was made by 2mm MDF and I have used 4mm nuts and bolts for the connections.
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07
.2
MODEL DEVELOPMENT 02
ERROR
The structure bends too much.
I have used 1mm thin card and 4mm nuts and bolts for the connections.
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07
.3
MODEL DEVELOPMENT 03
ERROR
The openings are very close to the edge and the structure is too thin. I used 2mm grey card and 2mm nuts and bolts for the connections.
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07
.4
MODEL DEVELOPMENT 04
ERROR
All the “X� scissors - like connections have been brought forward, and there are cracks on the structure.
I used 2mm grey card and 2mm nuts and bolts for the connections.
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07
.5
MODEL DEVELOPMENT 05
ERROR
The length of the “ring� components should be the same with the The components of the model
vertical scissors - like components. I used 2mm grey card and 2mm nuts and bolts for the connections. I have 3D printed the connection components.
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07
.6
MAKING THE RING & THE “LEGS”
ERROR
The structure bends too much and breaks under pressure.
•
To stop it from breaking, I have added extra material near the edges.
•
At the end, I found that connecting the legs with the ring, it won”t work.
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07
.7
FINAL MODEL
Making the scissors - like components
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The 3D printed hinges connect all the scissors - like components together and help the structure to fold and unfold. Why six sides? We know from Origami paper making that the folds have to be an even number so the structure can be folded and unfolded a lot faster.
To put together the hinges, I have used 1.8 mm copper rod. From the 1 meter long copper rod I cut pieces with length 45 mm. After inserted the copper rod into the hinge’s hole, I trimmed and bended the edges using pliers.
•
All the scissors- like elements have been laser-cut using 3mm black acrylic.
•
For All the connections, I have used 2mm nuts and bolts.
•
To put together the hinges, I have used 1.8 mm copper rod.
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Folding the scissors components
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The scissors components
3D printed Hinges Laser cut Black Acrylic
Laser cut Black Acrylic
Laser cut Black Acrylic - Acting as a washer
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The scissors components
scale 1:1
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The “feet” of the structure scale 1:1
The “feet” hold together the scissors - like components and help the structure to stand up.
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The “head” of the structure scale 1:1
The “head” holds together the acrylic struts. Under load pressure the cables going through the little ball like system (under the head while they are connected to the part of the bottom “legs”) will make the whole structure more stable. I used super glue to glue the 2 separate pieces.
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The “strut connectors� scale 1:1
The 3D printed components hold the struts. The struts are made from black acrylic. I used super glue to glue the 2 separate pieces.
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Final Model with cables
This structure is self-supported but it can be load-bearing - holding lightweight structures by attaching cables to the top and bottom part. The structure is stabilized into the deployed state by attaching the cables to the pivot point under the “head�. Under load pressure the compressive forces are resisted by the top struts while the tensile forces are resisted by the cables at the bottom of the structure and the shear forces are resisted by the scissors -like components. The cables are fishing wire with 0.45 mm thickness.
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08
CONCLUSION
In conclusion, it can be stated that the deployable technology in architectural
Deployable structures are easily foldable and transformable, thus, provides cost
industry has opened ways to modern developments, which can help in several
efficiency and ease of fabrication; this in turn, such structures help to design
ways. A number of factors to be considered here include that deployable
systems or structures that can be built through low cost materials. This is why
architecture helps to reduce size as well cost effectively. This is so because
it is said that deployable structures can be used to reduce expenditure too. De-
deployable structures are foldable and can reduce to bigger or smaller sizes.
ployable structures, thus, can be used for the development of accommodations
This helps in easy accommodation too.
aesthetically and programmatically.
It is also important to note that deployable architecture and structures can be
In this paper, it was identified that deployable structure is a kind of
structure that changes shape and correspondingly changes size as well. Deploy-
easily used and provided as a means of accommodation facility in areas that
able structures categorized for space crafts and others are basically categorized
have been hit by tsunamis and earth quakes. A transitional shelter may be
into 3 primary categories; where the 1st category is of articulated structure. The
provided to devastated communities in time of crisis management. Furthermore
second category is of on- orbit structures where device or structure is mechan-
continuous analysis and review, errors that are usually left out, previously, can
ically joined/ developed in space. Lastly, the third category of space based
be removed and new fold pattern can be generated that is error free. Also, with
deployable structures identified was of high strain structures.
the help of this step, different ways are suggested that show how a concept
Architectural designs and structures are quite beneficial since they
could be extended further on. Another example of deployable structure identified
help the owner to move around easily. In this paper, it was also identified that
in this paper is a solid surface deployable antenna. This research and construc-
folding and transformation helps the owner of a product to change its form when-
tion is beneficial for the understanding of deployable structures that can change
ever in need. For example, there are now such wooden or iron tables that can
the outlook of architecture in near future.
change shape and transform into smaller or bigger sizes depending upon the need of owner or user. Along with this, folding also helps the user to change the purpose of plain sheet of paper for which it may be used. Plain sheet of paper is usually used here in the context that deployable structures are made such that they resemble a plain sheet of paper and thus facilitates accommodation easily.
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BIBLIOGRAPHY
Adrover, E. R., 2015. Deployable Structures (Form + Technique). s.l.:Paperback. Britt, A. L. & Lalvani, H., 2014. Symmetry as a Basis for Morphological Analysis and Generation of NASA-Type Cubic Deployables. s.l.:Springer . Hoberman, 2011. Expanding Sphere (Estonia). [Online] Available at: http://www.hoberman.com/portfolio/sphere-estonia.php?&projectname=Expanding+Sphere+(Estonia) [Accessed 28 February 2016]. Jackson, Paul., 2011. Folding techniques for designers: from sheet to form. JAEA, 2008. HALCA. [Online] Available at: http://www.isas.jaxa.jp/e/enterp/missions/halca/ [Accessed 28 February 2016]. James, A. M., 2008. Deployable Architecture , s.l.: Georgia Institute of Technology. Pellegrino, S., 2014. Deployable Structures. s.l.:Springer. Pellegrino, S. & Guest, S. D., 2000. Solid Mechanics and Its Applications. s.l.:Springer . Pellegrino, S. & Guest, S. D., 2013. IUTAM-IASS Symposium on Deployable Structures: Theory and Applications: Proceedings of the IUTAM Symposium held in Cambridge, U.K., 6–9 September 1998. s.l.:Springer Science & Business Media. University-of-Surrey, 2016. FOLDING INFLATABLE STRUCTURES. [Online] Available at: http://www.surrey.ac.uk/ssc/research/space_vehicle_control/deploytech/science_and_tech/folding_inflatable_structures/ [Accessed 28 February 2016]. W, 2016. Welcome to Waymarking.com!. [Online] Available at: http://www.waymarking.com/waymarks/WMJ70X_Hoberman_Arch_Salt_Lake_City_UT [Accessed 28 February 2016].
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Weebly, 2015. Zsombor Nagy. [Online] Available at: http://zsombornagy.weebly.com/deployable-architecture.html [Accessed 28 February 2016].
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