truss

—trusser, n.

/trus/, v.t.

1. to tie, bind, or fasten.

2. to make fast with skewers, thread, or the like, as the wings or legs of a fowl in preparation for cooking.

3. to furnish or support with a truss or trusses.

4. to tie or secure (the body) closely or tightly; bind (often fol. by up).

5. Falconry. (of a hawk, falcon, etc.) to grasp (prey) firmly.

n.

6. Civ. Engin., Building Trades.

a. any of various structural frames based on the geometric rigidity of the triangle and composed of straight members subject only to longitudinal compression, tension, or both: functions as a beam or cantilever to support bridges, roofs, etc. Cf. complete (def. 8), incomplete (def. 3), redundant (def. 5c).

b. any of various structural frames constructed on principles other than the geometric rigidity of the triangle or deriving stability from other factors, as the rigidity of joints, the abutment of masonry, or the stiffness of beams.

7. Med. an apparatus consisting of a pad usually supported by a belt for maintaining a hernia in a reduced state.

8. Hort. a compact terminal cluster or head of flowers growing upon one stalk.

9. Naut. a device for supporting a standing yard, having a pivot permitting the yard to swing horizontally when braced.

10. a collection of things tied together or packed in a receptacle; bundle; pack.

11. Chiefly Brit. a bundle of hay or straw, esp. one containing about 56 lb. (25.4 kg) of old hay, 60 lb. (27.2 kg) of new hay, or 36 lb. (16.3 kg) of straw.

[1175-1225; (v.) ME trussen < OF tr(o)usser, var. of torser, prob. < VL *torsare, deriv. of *torsus, for L tortus ptp. of torquere to twist, wind, wrap; (n.) ME: bundle < OF trousse, torse, deriv. of torser]

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In building construction, a structural frame usually fabricated from pieces of metal or timber to form a series of triangles lying in a single plane.

The linear members are subject only to compression or tension. The horizontal pieces forming the top and bottom of the truss are called the chords, and the sloping and vertical pieces connecting the chords are collectively called the web. Unlike a vault, the truss exerts no thrust but only downward pressure; supporting walls require no buttressing or extra thickening. Trusses have been used extensively in roofing and bridges. Wood trusses were probably first used in primitive dwellings с 2500 BC. Wood was replaced by iron, which in turn was succeeded by steel.

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▪ building

      in engineering, a structural member usually fabricated from straight pieces of metal or timber to form a series of triangles lying in a single plane. (A triangle cannot be distorted by stress.)

      A truss gives a stable form capable of supporting considerable external load over a large span with the component parts stressed primarily in axial tension or compression. The individual pieces intersect at truss joints, or panel points. The connected pieces forming the top and bottom of the truss are referred to respectively as the top and bottom chords. The sloping and vertical pieces connecting the chords are collectively referred to as the web of the truss.

      Trusses were probably first used in primitive lake dwellings during the early Bronze Age, about 2500 BC. The first trusses were built of timber. The Greeks used trusses extensively in roofing, and trusses were used for various construction purposes in the European Middle Ages. Andrea Palladio's I quattro libri dell'architettura (1570; Four Books on Architecture) contained plans for timber trusses. A major impetus to truss design came in the development of covered bridges in the United States in the early 19th century. Cast iron and wrought iron were succeeded by steel for railroad truss bridges. The two systems most commonly used are the Pratt and the Warren; in the former, the sloping web members are parallel to each other, while, in the latter, they alternate in direction of slope. Trusses are also used in many kinds of machinery, such as cranes and lifts, and in aircraft wings and fuselages.

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