Components and Details
The beauty of fabric structures is in the few components required to create such a structure. These elements include the primary structure and specific components related to the structure, the fittings and hardware used to tension the membrane and the membrane itself.
Mast or Compression Members
Most fabric structures require a compression member (mast or arch) to form a complex shape. The component usually has welded “cleats” or “struts” which enable it to support the membrane, cable or other structural components.
The base plate forms the connection between the tension membrane structure and the ground, wall, building or adjacent structural system. The base plate is usually welded to the bottom of a compression member or separated from the mast and connected to the mast with a pin connection.
Membrane plates are the most time consuming components to design and the key to successful tension membrane structures. Membrane plates provide a “link” from the membrane to the structural masts. These plates are installed to accept membrane catenary cables and pin connection hardware.
“Catenaries” are formed along the fabric perimeter stretching from mast to mast. Catenary cables are installed inside a pocket in the membrane or supported along the edge with cable straps and usually terminated with a threaded end stub or forked clevis that is connected to the membrane plates.
Each perimeter mast requires either a large moment connection or a series of cable tie downs to withstand the loads. Tie down cables are generally attached to cleats on the top of a mast and connected to anchors installed in the ground with turnbuckles. Specialized HardwareFabric Structure hardware consists mostly of parts made for yacht racing, bridge building, rigging and mountain climbing industries. Shackles, turnbuckles, “toggles” and carabineers are just a few of the hardware choices available. These components are the link between the membrane and the primary structural support.