truss

truss, in architecture and engineering, a supporting structure or framework composed of beams, girders, or rods commonly of steel or wood lying in a single plane. A truss usually takes the form of a triangle or combination of triangles, since this design ensures the greatest rigidity. Trusses are used for large spans and heavy loads, especially in bridges and roofs. Their open construction is lighter than, yet just as strong as, a beam with a solid web between upper and lower lines. The members are known as tie-beams, posts, rafters, and struts; the distance over which the truss extends is called the span. The upper and lower lines or beams are connected by web members.

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truss

A truss's outer members are called the chords, its interior members are called the web members, and …

(credit: © Merriam-Webster Inc.)

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 c. 2500 BC. Wood was replaced by iron, which in turn was succeeded by steel.

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truss

1. Med a device for holding a hernia in place, typically consisting of a pad held in position by a belt

2. Horticulture a cluster of flowers or fruit growing at the end of a single stalk

3. Nautical a metal fitting fixed to a yard at its centre for holding it to a mast while allowing movement

4. Architect another name for corbel

5. Chiefly Brit a bundle of hay or straw, esp one having a fixed weight of 36, 56, or 60 pounds