Design of Adaptables Structures Based on Application of Observed Principles in the Nature

Marroquín Rivera, Luis Alberto San Martin de Porres University Faculty of Engineering and Architecture 1250 La Fontana Ave.,Lima , PERU amarroquin@usmp.edu.pe

KEYWORDS Kinetic, fractal frame, unlimited growth, inflatable. 1. INTRODUCTION Nature is an infinite source of inspiration for all designers; the performance of the designs observed in its creatures surprises us every day, due to the fact that we achieve a better knowledge of the natural world. The principles of design used by nature are countless; in all of them we find an harmonic combination of parts that are destined to one purpose, This purpose is create a perfect balance with the environment. Biological analogies Moderns architects like Sullivan, Wright, Le Corbusier, R. Buckminster Fuller and Otto Frei employed biological analogies and the concept of the organic. Both of these concepts are central to the twentieth century. In our case three specific characteristics that we observe in the constructions of nature can be used in the creation of analogical designs of adaptable structures with excellent earthquake-resistant performance and minimum quantity of mass:

a) Traction and resilience.- Is the study of organic structures, which strategy of design is the

create mechanisms where predominate the efforts of traction with materials of high elasticity and resilience. These two characteristics are used to achieve a high performance with minimum energy consumption; we observe them in the spider webs (figure 1). Structures made with organic material and excellent properties of traction and resilience.

b) Self-similarity and homotecy. Is the strategy of repeating a formal pattern of different scales, the goal is to generate a stable mechanism that can extend its volume and mass without losing the original form, we can observe this strategy in the vegetable kingdom and in the shells of molluscs. ( figure 2 )

c) Expansible pneumatic membrane. Is the analysis of mechanical design of insect wings (figure 3)

Figure 1. Spider web Figure 2. Nautilius Shell Figure 3. Dragonfly wing

2 DEVELOPMENT OF PROTOTYPES 2.1 The pentatensegrity house

The inspiration comes from the spider web, which uses the fibers to minimize the quantity of mass in the structure. Webs of araneid spiders have several structural devices designed to absorb the impact energy. Space frame: This prototype is constructed in a module named “Dodecahedral space frame” The module is assembled by the platonic bodies (tetrahedron, cube, octahedron, dodecahedron and icosahedron). The mathematical relationships between the bodies is the classic golden ratio. The principle of the tensegrity developed by Buckminster Fuller in the 1950s is used to convert the “dodecahedral module” (figure 5) to “tensegrity dodecahedral module”. (Figure 6) The dodecahedral tensegrity is made of rigid post and coil spring to absorb the impact of the outer forces.

The pentatensegrity house is the integration of five “tensegrity dodecahedral modules” that work in perfect structural unit. The construction and test of prototypes is an integral part of structures adaptables development

Figure 6. Dodecahedral tensegrity

Figure 5. Dodecahedral module

Figure 4. The Platonic bodies

Figure 8. Tensegrity system Figure 7. Architectural model

Figure 9 .The prototype absorbs the impact of the outer forces.

Figure 10 . The prototype recovers its original form

2.2 Logarithmic Geospiral Dome The geometry used for the space frame of this model, is the spiral generated by a recursive nest of Golden Triangles. This is the classic shape of the Chambered Nautilus shell. The curve of this shell is called Equiangular or Logarithmic spirals and is common in nature to build this armour. Creatures use the same proportions for each expanded chamber that is added; growth follows a law which is everywhere the same. The prototype is based on a pattern of the fractal geometry. The geometric characterization of the simplest fractals is self-similarity: where the shape is made of smaller copies of itself. The copies are similar to the whole: same shape but different size.

The “Logarithmic Geospiral Dome” is based on a geometry which allows an unlimited growth in function the increase of needs of space. The model uses the strategy of repeating a formal pattern of different scales. This is made to generate a stable mechanism that can extend its volume and mass without losing the original form.

The Logarithmic Geospiral Dome is retractable by pulling outwards at the base. The driving system used to open and close the retractable dome is a wire traction system, which has a simple movement and does not require a lot of maintenance.

Figure 11. The protoype is assembled by an stable mechanism that can extend its volume and mass.

Figure 13 . Percentage of opening of the retractable dome.

35%

85% 100%

5%

Figure 12. The spaceframe is made of smaller copies of itself.

2.3 Kaleidocyclical Pneumatic membrane. The design is based around a few basic ideas: a) The Metamorphosis of the Dragonfly, The inspiration comes from the transformation of the nymph in a flying creature; there are a series of special mechanisms that help the dragonfly to shed its skin. The body of the dragonfly shrinks and becomes wrinkled in the old body. In order to open this body, a special pump system and a special body fluid are created to be used in this process. These wrinkled body parts of the insect are inflated by pumping body fluid after getting out through the slot. In the meantime, chemical solvents start to break the ties of the new legs with the old ones.

b) The inflatable structures These structures are typically classified as Pneumatic structures (figure 15) and are structural forms stablized wholly or mainly by pressure differences of gases, liquids, etc. Tensile stress pneumatic structures can be readily made from light collapsible, very strong membranes. They basically fall into three categories: single-layer air supported, air-inflated structures, and inflated ribbed structures. c) The Kaleidocycle The kaleidocycle are three-dimensional ring made up of tetrahedrons united by their edges. They can turn on if same infinite times without breaking themselves nor becoming deformed themselves around his centre. The Kaleidocyclical Pneumatic membrane This prototype is a radical new form; It is the combination of three concepts: air-Inflatable structure, Kinetic kaleidocycle and deployable systems in nature.

Figure 14 . The Metamorphosis of the Dragonfly, body parts of the insect are inflated by pumping

body fluid.

Figure 15 . Inflatable Geodesic stabilized by pressure of gases

developed in the 1940s

Figure 16. The four kinetic transformation of the Kaleidocyclical Pneumatic module

Figure 17. The kaleidocyclical pneumatic membrane is the integration of several “kaleidocyclical pneumatic“modules.

3 DEVELOPMENT OF PROTOTYPES The potential of these adaptables structures is enormous, I would thank to the characteristics of

flexibility, rapidity of assemblage, excellent earthquake-resistant performance, minimum quantity of mass, savings on installation costs and the potential for more rigorous factibility studies by computer.

All of these all possibilities for the application in architecture, structures and construction industry

can be adapted to multiple functions: Pavilion, auditorium, theatre, gallery, house, playground equipment for kids, etc.

4. REFERENCES D’Arcy Wentworth Thompson, 1961, On Growth and Form, Cambridge University Press, London. Doczi Gyorgy, 1981 , Power of Limits , Shamballa Publications INC, Boston, Massachusetts. Mandelbrot, Benoît B. 1982, The Fractal Geometry of Nature. New York: W. H. Freeman and Co. Marks, Robert W, 1962, The dymaxion world of Buckminster Fuller, New York : Reinhold Pub. Corp Otto, Frei, 1973, Tensiles structures : design, structure, and calculation of buildings of cables, nets,

and membranes Cambridge : The MIT Press. Pallasmaa Juhani, 2001, Animales Arquitectos.El funcionalismo ecológico de las construcciones

animales Colección Cuadernas, Fundación César Manrique, Madrid, Spain. Steadman, Philip, 1979, The evolution of designs; biological analogy in architecture and applied arts,

Cambridge: Cambridge University Press. Wright, Frank Lloyd, 1958, The future of architecture, Buenos Aires : Poseidon.

Figure 18 The structure of the pentatensegrity house

Figure 19 The logarithmic geospiral dome