Terminology for Tension Structures and Tensile Facades
C
Cable Cuff
Edge treatment in which the fabric is folded over on itself to form a pocket in which a catenary cable can be installed.
Cable Fitting
A device attached to the end of a cable to allow a connection to another member. Fittings can be swaged, speltered, or compression type.
Catenary
The curve theoretically formed by a perfectly flexible, uniformly dense, inextensible “cable” suspended from each of two end points. In fabric structures experience, this shape is probably not ever truly developed, but is commonly used to describe the shape developed at the boundary of a uniformly stressed fabric structure attached to a cable, which is restrained only at its endpoints.
Catenary Cable
Steel cables that run through the pockets on the perimeter of a tension structure fabric. The shape of the cable follows that of the pocket, which is typically curved with a ratio of 1:10. The length of the cable is to be determined by the engineer supplying the fabric patterning. The thickness of the cable is to be determined by the engineer who is calculating the reaction loads at the cable ends.
Catenary Edge
Method of securing the edge of a panel with a cable tensioned between two fixed points.
Catenary Pocket (AKA “Banana Pocket”)
This is the pocket that is placed at the perimeter of the fabric cover to secure the catenary cable. The pocket has a curve with a ratio that is defined by the fabric patterning, but is typically close to a 1:10 ratio. This means for every 10 feet of length, there will be about a foot of bend to it. Due to the curvature of the shape, the pocket is typically fabricated by sealing together two halves of the pocket with an overlap of 1” to 2” at the outside edge of the pocket.
Clevis
Device used with a cable stud end or a threaded rod to form a pinned connection that is somewhat adjustable.
Compensation
The operation of a shop fabricating a fabric structure or pieces of the structure, smaller in the unstressed condition than the actual installed size, to account for the stretch at pre-stress level.
