ABSTRACT
Tension structures can take a variety of potential forms based on the geometry of the cable, the type of supporting elements, how they are stabilized, and how enclosure is achieved. Suspended and cable-stayed structures support loads with tension-based members. In suspended structures, the loads collect and increase along their lengths up to the supports–they can be calculated like the forces in an arch. In cable-stayed structures, load-bearing cables pull the forces upward diagonally in tension towards the top of the support tower. Changes to the loading conditions, particularly wind uplift or concentrated point loads, can also make the structure change shape and become unstable. The most famous example of how lightweight tension structures can be threatened by instability is the collapse of the Tacoma Narrows Bridge in Washington, in 1940. Tension structures rely upon load-bearing compressive members to transfer their loads to the ground. There are two kinds of pneumatic structures, the air-inflated and the air-entrained.
