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Tensegrity in Architecture  by: Dennis E. Hayes, R&D Engineer

An Arbelos solar pyramid home has ‘Tensegrity’ in its structural system, allowing it to stabilize itself mechanically because of the way in which tensional and compressive forces are distributed and balanced within the structure. This fundamentally new principle of Tensegrity allows for a stronger structure.

The word Tensegrity is a contraction of the term 'tensional integrity.' Tensegrity describes a structural-relationship principle in which structural shape is guaranteed by the finitely closed and continuous, tensional behaviors of a systems members, and not by the discontinuous and exclusively local compressional members behaviors. Tensegrity provides a structure the ability to yield increasingly without ultimately failing, breaking or coming apart.

When I first saw the "Eagles" predecessor (LEM-Lunar excursion module) hanging in Bucky’s dome (The U.S. Pavilion) at "Montrel-67" I suspected the engineers conceived that design from nature, namely the Bacteriophage. Having a background in science, especially Biology has led me to contemplate and emulate designs of nature, which in their simplicity, form intrinsically complex systems, that possess balance, symmetry and beauty. Architecture and design require simplicity of form and balance to achieve natural strength and beauty.

Some of my early hero’s were Watson and Crick who discovered the DNA molecule’s double helix, structure, and Buckminster Fuller who discovered the Geodesic dome and "Bucky Balls" which form "Bucky Tubes" one of the strongest micro structures that we know of today, composed only of carbon atoms. Like graphite and diamonds, the difference of it being soft or the hardest mineral known is dependent on how those atoms are arranged. So what a crystals physical, mechanical and electrical properties are depends on its atomic structural bonding arrangement.

Tensegrity structures are mechanically stable; because of the way the entire structure distributes and balances mechanical stresses. These structures fall into two categories, the first includes the geodesic domes of Buckminster Fuller. Their frameworks are made up of rigid struts, each of which can bear tension or compression. The struts of the framework are connected into triangles, pentagons, hexagons, to form a polyhedron; each strut is oriented to constrain each joint in fixed position, assuring the stability of the structure.

The other category of Tensegrity structures, Snelson structures stabilize themselves through what is known as pre-stress. The structural members that can bear tension are distinct from those that bear compression. Even before these structures are subjected to external forces, all the structural members are already in tension or compression. They are pre-stressed. Within the structure, the compression-bearing rigid struts stretch, or tense the flexible tension-bearing members, while those tension-bearing members compress the rigid struts. These counteracting forces are equalized within the structure and enable it to stabilize itself, into a balanced system.

Technical evolution has a behavior pattern. First there is scientific discovery of a principle, by a subjective realization of an experimentally probing individual. Next comes objective employment of that principle in a special invention. Next the invention becomes practice. This gives humans a technical advantage over the physical environment. If successful, the invention is used in bigger, better and swifter ways. For instance, Fulton’s small steamship progressed to a bigger ocean cruiser, then to even bigger; swifter, higher-powered oceanic giants like the Titanic then Aircraft Carriers. Subsequently they are engineered to achieve sleekness, increase speed, efficiency and economy. Weapons Technology follows this fundamental evolutionary pattern of bigger, then smaller, i.e. Missiles and smart bombs (more killing, less human effort, greater distances, higher speeds, and increased accuracy).

Technical curves rise in size, weight and volume to reach a giant peak, then progresses to miniaturization. After that, economical art takes over and then goes through a similar cycle of doing progressively MORE WITH LESS, first by getting bigger and taking advantage of volumetric principles, for instance, doubling the length of a ship increases its wetted surface fourfold but increases its payload volume eight fold. This principle is true for ships of both water and air. Then comes miniaturization, the trend to DO MORE WITH LESS. Trends toward the goal of doing everything with nothing at all, which is a trend of the measurable physical to be mastered by the in-measurable metaphysics of intellect.

My interests in Tensegrity started from my studies in biology, chemistry, physics and architecture. I began to realize that how living things are formed, had less to do with chemical composition than with architecture. All natural systems like carbon atoms, water molecules, proteins, viruses, cells, tissues and living creatures, are constructed using the form of architecture known as Tensegrity. Nature applies common assembly rules from the molecular to the macroscopic scale, of certain patterns like spirals, pentagons and triangulated forms. These patterns appear in structures ranging from crystals to proteins and in organisms like viruses, plankton and humans. All organic and inorganic matter is made of the same building blocks, atoms of carbon, hydrogen, oxygen, nitrogen and phosphorus.

The only difference is how the atoms arrange in three-dimensional space. The phenomenon, by which components join together to form larger, stable structures is known as self-assembly, the principal behind Nanobot Technology. It is observed in all forms of nature. Molecules self-assemble into cellular components (organelles), which self-assemble into cells; then self-assemble into tissues, which self-assemble into organs. The result is a hierarchy of tiers of systems within systems. Understanding the way living creatures form, and function will reveal the basic principles of biological organization. Physical laws govern this formation of building to achieve the simplest and strongest structure possible the triangle. Then builds polygons and polyhedrons from these triangular forms into structural systems, of infinite variations. Mother Nature does MORE WITH LESS. It’s an energy thing, conservation and concentration.

Tensegrity structures of both categories share one important feature, which is that tension is continuously transmitted across all structural members. An increase in tension in one of the members results in increased tension in members throughout the structures, even ones on the opposite side. The increase in tension is balanced by an increase in compression within certain members throughout the structure. The structure stabilizes itself through a mechanism that Bucky Fuller described as continuous tension and local compression.

Most buildings (Post and Beam construction) derive their stability from continuous compression, relying on the force of gravity. They are weak in other planes when external forces are applied, like wind forces, snow loads and seismic racking forces. This is why the collapse, when wind or snow loads exceed their design load limits, shake apart during earthquakes, implode during tornado or hurricane wind forces or have their roofs removed when winds get under the eaves.

The tension-bearing members in these structures, whether Fuller's domes or Snelson structures, map out the shortest paths between adjacent members, and are arranged geodesically. Tensional forces naturally transmit themselves over the shortest distance between two points, so members of a Tensegrity structure are precisely positioned to best withstand stress. This is why Tensegrity structures offer a maximum amount of strength for a given amount of building material. The pyramids structural members are in balance in both tension and compression at their apexes, which make it one the strongest geometrical structures.

We know very little about the forces that guide atoms to self-assemble into molecules. We know even less about how groups of molecules join to create cells and tissues, how tissues form organs. Recent advances in the human genome project, and cloning promise major breakthroughs in understanding these forces.

What we at Arbelos Homes know is that the Pyramid form in its simplicity and naturally inherent strength, is the logical solution for safe, efficient and economical structures in the future. Our solar pyramid homes adhere to the physical laws of nature.

Written in 2001 

Dennis E. Hayes
Research & Development Engineer
Receipient of Design Award from Machine Design Magazine 

Arbelos Homes LLC * 8311 Greenwood * Raytown * MO * 64138