2. CABLE
STRUCTURAL CABLES ARE MADE OF A
SERIES OF SMALL STRANDS TWISTED OR
BOUND TOGETHER TO FORM A MUCH
LARGER CABLE. STEEL CABLES ARE
EITHER SPIRAL STRAND, WHERE
CIRCULAR RODS ARE TWISTED
TOGETHER AND "GLUED" USING A
POLYMER, OR LOCKED COIL STRAND,
WHERE INDIVIDUAL INTERLOCKING
STEEL STRANDS FORM THE CABLE.
3. CABLE
A CABLE IS A FLEXIBLE STRUCTURAL COMPONENT THAT OFFERS NO
RESISTANCE WHEN COMPRESSED OR BENT IN A CURVED SHAPE.
TECHNICALLY WE CAN SAY CABLE HAS ZERO BENDING RIGIDITY.
A CABLE IS THE MAIN COMPONENT OF CABLE SUPPORTED BRIDGE
OR SUSPENDED ROOF STRUCTURES THAT ARE CLASSIFIED AS
FOLLOWS:
1. SUSPENSION TYPE CABLES
- The main forces in a suspension bridge of any type
are tension in the cables and compression in the pillars.
This not only adds strength but improves reliability
2. STAYED TYPE CABLES
- The towers are the primary load-bearing structures
which transmit the bridge loads to the ground.
4. THE FIRST SUSPENDED ROOF
PROTOTYPE, BANSKA, BRYSTICA,
SLOVACIA, 1826, VENRICH
SCHNIRCH ARCH
8. TENSILE
A TENSILE STRUCTURE IS A CONSTRUCTION OF ELEMENTS
CARRYING ONLY TENSION AND
NO COMPRESSION OR BENDING. THE TERM TENSILE SHOULD
NOT BE CONFUSED WITH TENSEGRITY, WHICH IS A
STRUCTURAL FORM WITH BOTH TENSION AND COMPRESSION
ELEMENTS. TENSILE STRUCTURES ARE THE MOST COMMON
TYPE OF THIN-SHELL STRUCTURE. MOST TENSILE STRUCTURES
ARE SUPPORTED BY SOME FORM OF COMPRESSION OR
BENDING ELEMENTS, SUCH AS MASTS, COMPRESSION RINGS
OR BEAMS.
9. TENSILE
A TENSILE MEMBRANE STRUCTURE IS MOST OFTEN
USED AS A ROOF, AS THEY CAN ECONOMICALLY
AND ATTRACTIVELY SPAN LARGE DISTANCES.
10. Tensioned Fabric Structure:
A structure where the exterior shell
is a fabric material spread over a
framework. The fabric is
maintained in tension in all
directions to provide stability.
VS.
Tensile Structures:
Tension roofs or canopies are
those in which every part of the
structure is loaded only in tension,
with no requirement to resist
compression or bending forces.
11.
12.
13. TYPES OF TENSILE STRUCTURE
A two-dimensional tension fabric membrane can take planar tensile forces, but it
cannot take significant forces perpendicular to this plane. Therefore, in addition to
being pre-stressed, tension fabric must take a certain three-dimensional shape, in
order to remain stable. These shapes were discovered by Otto and Berger during their
investigation of natural forms, such as soap bubbles. There are two types of general
shapes: Anticlastic and Synclastic Shapes.
14. ANTICLASTIC SHAPES
Anticlastic Shapes are created by having the radii of the principal curvatures on
opposite sides of the tension fabric surface. As a result, when loaded at a particular
point, tension will increase on one curve of the membrane and leave the opposite
curve. Thereby, preserving equilibrium and keeping the structure stable. In order to
keep anticlastic shapes, some kind of structural frame or support is necessary in the
form of cables or steel beams. Some examples of anticlastic shapes are saddle,
cone and wave forms.
15. SYNCLASTIC SHAPES
Synclastic Shapes are characterized by having the radii of the principal curvatures on
the same side of the fabric. In order to counteract external forces, pressure from the
within is necessary. This is why synclastic shapes are associated with air-inflated
structures. The difference of pressure created by air pumped into the building is able
to counteract the external forces, in the form of wind or snow.
21. RUSSIAN ENGINEER VLADIMIR
SHUKHOV WAS ONE OF THE FIRST TO
DEVELOP PRACTICAL CALCULATIONS
OF STRESSES AND DEFORMATIONS OF
TENSILE STRUCTURES, SHELLS AND
MEMBRANES. SHUKHOV DESIGNED
EIGHT TENSILE STRUCTURES AND THIN-
SHELL STRUCTURES EXHIBITION
PAVILIONS FOR THE NIZHNY
NOVGOROD FAIR OF 1896
ENGR. VLADIMIR
SHUKHOV
22. ANOTHER WORK OF VLADIMIR SHUKHOV
IS THE SIDNEY MYER MUSIC BOWL,
CONSTRUCTED IN 1958. IT IS LOCATED IN
MELBOURNE. THE BOWL'S CANOPY
CONSISTS OF A THIN MEMBRANE MADE
OUT OF HALF AN INCH WEATHER-
PROOFED PLYWOOD SHEETED ON BOTH
SIDES WITH ALUMINIUM ATTACHED TO A
COBWEBBED FRAME OF STEEL CABLES
AND SUPPORTED BY 21.3 METRES (70 FT)
MASTS PIVOTED TO THE EARTH. THE TOTAL
AREA OF THE CANOPY IS 4,055 SQUARE
METRES (43,650 SQ FT). THE MAIN CABLE
AT THE EDGE OF THE CANOPY
COMPRISES 7 ROPES, EACH ABOUT 9 CM
IN DIAMETER AND 173 METRES (568 FT)
LONG, ANCHORED DEEP INTO THE
GROUND IN CONCRETE BLOCKS.
LONGITUDINAL CABLES HOLD UP THE
ROOF AND TRANSVERSE CABLES HOLD IT
DOWN.
23. German architect and structural
engineer Frei Otto was well known for
his pioneering innovations in
lightweight and tensile structures. In
many ways, Otto was far ahead of his
time and sought new methods to use
the least amount of material and
energy to create space, embracing
principles of sustainability long before
the term was coined in architecture.
His interest in going beyond the
discipline of architecture is evident in
his fascination with
experimentation as he spoke of the
need to understand the "physical,
biological and technical processes
which give rise to objects." One can
see his interests in natural phenomena
such as bird skulls, soap bubbles, and
spiders' webs as they are translated
into man-made forms that appear
incredibly delicate and elegant.
AR. FREI OTTO
24. PERHAPS HIS BEST KNOWN WORK,
THE 1972 MUNICH OLYMPIC STADIUM, IS
A STRIKING EXAMPLE OF HOW OTTO
GRACEFULLY APPLIED THE MANY
LESSONS HE LEARNED IN TENSILE
STRUCTURES. OTTO USED THE IDEA OF
ANTONIO GAUDI FOR THE ROOF OF THE
OLYMPIC STADIUM IN MUNICH.
29. WHY USE TENSIONED MEMBRANE STRUCTURE?
• Flexible Design Aesthetics - Tensile fabric structures provide unlimited designs of distinctive
elegant forms that can be realized because of the unique flexible characteristics of
membrane.
• Outstanding Translucency - In daylight, fabric membrane translucency offers soft diffused,
naturally lit spaces reducing the interior lighting costs while at night, artificial lighting creates
an ambient exterior luminescence.
• Excellent Durability - With several different membranes in the market place such as PTFE
fiberglass, ETFE film, PVC and ePTFE, the durability and longevity of tensile membrane
structures have been proven and built in climates ranging from the frigid artic to the
scorching desert heat.
• Lightweight Nature - The lightweight nature of membrane is a cost effective solution that
requires less structural steel to support the roof compared to conventional building
materials, enabling long spans of column-free space.
• shipment.
30. • Low Maintenance - Tension fabric structures are somewhat unique in that they require
minimal maintenance when compared to an equivalent-sized conventional building.
• Cost Benefits - Most tensile membrane structures have high sun reflectivity and low
absorption of sunlight, resulting in less energy used within a building and ultimately
reducing electrical energy costs.
• Variety of Membranes - Whether it’s a permanent durable structure that needs to last
longer than 30 years, an insulated membrane system for thermal performance or a
deployable flexible application, there are a variety of tensile membranes to choose
from to meet specific performances for your next building project.
• Sustainable Building Material - By using translucent tensile fabric membranes like PTFE,
PVC, Insulated Tensile Membrane or transparent ETFE films, daylight is maximized in
building interiors, thus reducing the costs for electric lighting.
Group 2:Mimi Alguidano