3501 Portfolio

Materials Catalogue | Studio 3501 | Fall 2008

History of Tensile Structures Tensile structures were first seen in the earliest forms of shelter, such as the tent. However it was Vladimir Shukhov who pioneered the use of tensile structures in the late 19th & early 20th centuries by doing many shell tower and pavillions such as the Elliptical Pavillion of the Panrussian Exposition in 1896. These structures began an era of tensile creations done by many well known architects and engineers such as Eero Saarinen, Santiago Calatrava, Frei Otto, and many others. Although we have been using tension in our structures for many centuries, it only recently has become a form of art. As these structures progressed they began to seperate themselves into three different categories: Linear, 3-Dimensional, and surface stressed. These structures began as Linear tensile structures such as the pavillion above by Shukhov. They were more simplistic designs that had linear cables in tension forming a space. In later years these structures began to take several different forms of more complex shapes. The 3-dimensional forms started as very sculptural towers and other vertical forms. The last of the three categories is surface stressed tensile structures. This type of construction can take many different forms given its flexibility of materials. All of these different types of tensile construction are unique but all remain to have their main force of tension.

Materials Catalogue | Studio 3501 | Fall 2008

Linear Structures The Chords bridge in Jerusalem, Israel was done by Santiago Calatrava in 2008. It is a cable stayed bridge composed of 66 steel cables. It has one angle, cantilevered tower supported by the cables. The goal of the bridge was to add a unique defining aspect to the jerusalem skyline. These tensile structures often have a great beauty to them, but can also be much more costly than a more simple and traditional solution. On this particular project many of the cities tax payers were skeptical on how much this project was costing them. Although these structures are more expensive than a standard concrete or compression bridge, there structural longevity and stability offsets the price jump. This bridge, although beautiful and streamlined, is extremely simplistic in comparison to the other types of tensile construction. Linear structures typically have a central mast, just as the chords bridge, with strategically placed cables anchored to the ground in order to support the structure. When you begin to get into 3D and surface stressed tensile structures, the placement, forms, and mathematics begin to become much more complex.

Materials Catalogue | Studio 3501 | Fall 2008

3D Structures A typical 3D tensile structure can be not only in tension, but in compression as well. When this occurs, as it has in the sculpture to the left, the inner members are in compression while the outer members are in tension, causing tensegrity. Another example of a 3D tensile structure is the “bicycle wheel” used as a structural roof. As seen above, there are steel members in tension on a lower and upper deck forming a volume in between. This unique feature is what makes these types of tensile buildings different from a linear structure. Although these structures and buildings have a more complex shell, it makes for a more interesting shape. The inner ring of this structure is in tension while the outer ring is in compression. These opposing forces is what causes the cables and steel members to take their shape in between the two concentric rings. These structures are much more complex than the simpler linear tensile structures making them more expensive, however they are extremely well crafted There are not very many of these unique structures.

Materials Catalogue | Studio 3501 | Fall 2008

Surface Stressed Structures The Olympic Stadium in Munich, Germany done by the engineer Frei Otto for the 1972 Olympics is an example of a surface stressed structure that uses acrylic glass stablized by steel cables that are in tension. The idea was to symbolize the swiss alps with its white transparent shield. This new form of structure has opend up many new possibilities in the 20th and 21st centuries with its flexibility for new shapes and forms that traditional hard surfaced materials can not provide. It also gives a lightness quality that hard surfaced coverings can not provide, along with bringing in natural lighting to the space below. Another example of these membranes is the millenium dome. This structure, although it does not have the hyperbaloid effect that the Olympic park has, it has still has a stretched membrane that has been formed into a dome. These complex shapes take much planning and placement in order to get the perfect balance of tension so that the weight is distributed in the correct way to hold everything up. With these surface stressed str