Form active structure are those active structures in which loads are taken by the form or the shape of the structure. These are also known as adaptive mechanical structures in which form of the structure / building can altered mechanically in response to environmental changes. Form Active Structure Systems redirect external forces by simple normal stresses: the arch by compression, the suspension cable by tension. The bearing mechanism of form active structure systems vests essentially on the material form. Only tensile and compressive stresses persist.
Types of Form Active Structure System
These are mainly categorized into 4 types:-
# Cable Structure
# Arch Structure
# Tents Structures
Cable Structure:
Cable Structure System is the major system under form active structure system. It comprises of non-rigid, flexible cables shaped in a certain manner and fixed at the ends to span the space. The load is transmitted through simple stresses; either through compression or tension. Cable system forms a Funicular Shape through the stresses. The high tensile strength of steel, combined with the efficiency of simple tension makes a steel cable the ideal structural element to span large distances.
Arch Structure:
An Arch is a compression form and a vertical or horizontal structure, curved in a manner that spans a space. It may or may not support the load above it depending upon the form. It can span large areas through compression stresses neglecting tensile stresses. All the bridges and old historical buildings were made in arch structure system. Arches are mainly of three types: Circular Form, Pointed Aches and Parabolic Arches.
Tent Structure or Tensile Structure:
Tent or Tensile structures are the common type of thin – membrane structures which only carry tension stresses and no bending or compression. The most important and wide usage of these structures is in roof due to its low cost and spanning capacity of large spaces. They are also used in making complete building structure such as exhibition halls, warehouses etc. Main materials required for these type of structures is tensile membrane and steel cables. There are mainly 4 types of tents fabric structures: Saddle roof, Arch supported, Mast supported and combinations.
Pneumatic Structures:
These are the type of membrane structures which are stabilized by the pressure of compressed air. The membrane fabric is stiffened by the network of cables and the rigid ring at the edge supports the assembly. There are majorly two types of pneumatic form active structure systems – Air Supported Structures and Air Inflated Structures. Pneumatic Structures are lightweight, safe structures which enable natural light to enter the space and take least time for erection and dismantling.
For more information, check the presentations which have been posted by our contributors sourced from Google.
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