Bent (structural)

A bent in American English is a transverse rigid frame (or similar structures such as three-hinged arches). Historically, bents were a common way of making a timber frame; they are still often used for such, and are also seen in small steel-frame buildings, where the term portal frame is more commonly used.

The word "bent" is also used for the horizontal element of a two-pier bridge support, which is a support consisting of two vertical piers, each approximately at the outer edge of the bridge deck, and a single horizontal element connecting the tops of the two piers. In British English this assembly is called a "cross frame". An "outrigger bent" is one where the vertical piers are located outside the bridge's deck, hence the horizontal bent is wider than the bridge deck.

The term bent is probably an archaic past tense of the verb to bind, referring to the way the timbers of a bent are joined together. The Dutch word is bint (past participle gebint), the West Frisian is bynt, and the German is bind. Compare this with the term bend for a class of knots.

Bents are the building blocks that define the overall shape and character of a structure. They do not have any sort of pre-defined configuration in the way that a Pratt truss does. Rather, bents are simply cross-sectional templates of structural members, i.e., rafters, joists, posts, pilings, etc., that repeat on parallel planes along the length of the structure. The term bent is not restricted to any particular material. Bents may be formed of wooden piles, timber framing, steel framing, or even concrete.