In this light truss bridge each side truss has sixteen elements. A truss bridge is a Bridge composed of connected elements (typically straight which may be stressed from tension, compression, or sometimes both in response Of these, 7 are in compression and are fabricated as lattice beams. The remaining 9 elements are only in tension and are composed of eyebars. Shear and bending forces are accommodated completely within the deck structure.

In structural engineering and construction, an eyebar is a straight bar, usually of metal, with a hole ("eye") at each end for fixing to other components. Structural engineering is a field of Engineering dealing with the analysis and design of Structures that support or resist loads Structural engineering is The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Eyebars are used in structures such as bridges, in settings to which is applied only the force of tension, and not compression. A bridge is a Structure built to span a Gorge, Valley, Road, railroad track, River, Body of water In Physics String Tension is the magnitude of the pulling force exerted by a string cable chain or similar object on another object Physical compression is the result of the subjection of a material to Compressive stress, resulting in reduction of Volume.

Shape

Detail view of pin joined eyebars on truss structure

A closed eyebar will typically have a rectangular cross section of constant thickness throughout its length and a constant width for all but the ends. In Geometry, a rectangle is defined as a Quadrilateral where all four of its angles are Right angles A rectangle with vertices ABCD would be denoted as The ends will transition to a wider part that is terminated by a rounded end. In the center of this end will be a hole which will receive a cylindrical pin, which may have provision to accept one or more nuts or bolts. A cylinder is one of the most basic curvilinear geometric shapes the Surface formed by the points at a fixed distance from a given Straight line, the axis A nut is a type of Hardware Fastener with a threaded hole Nuts are almost always used opposite a mating bolt to fasten a stack of parts together If of round cross section the bar will typically be end-forged to create a head, which is then flatted by additional forging. The head may then be machined to a precise thickness and flatness. An alternative method for using round bar is to form a loop and to forge-weld (hammer weld) or electrically weld the free end to the main bar.

Open eyebars are used in the cable anchorages of modern wire-cable suspension bridges. This allows the wires to be looped over the eye, rather than requiring threading through a closed eye.

Application

A chain suspension bridge - Clifton Suspension Bridge

In trusses

Eyebars are used in portions of pin-jointed trusses where it can be established by engineering procedures that the bar will not be imposed with any stress other than tension under all expected conditions. The Clifton Suspension Bridge is a Suspension bridge, spanning the Avon Gorge and linking Clifton in Bristol to Leigh Woods in In Architecture and Structural engineering, a truss is a structure comprising one or more triangular units constructed with straight slender members whose

In chain link suspension spans

The links are often redundant in two dimensions. The preferred substitute for eyebar chains uses multiple strands of drawn wire to form substantial cables - see suspension bridge. This article is concerned with a particular type of suspension bridge the suspended-deck type As to why low-redundancy chain link suspension spans are not favored, see Silver Bridge. The Silver Bridge was an Eyebar Chain Suspension bridge built in 1928 and was named for the color of its Aluminum paint

Fabrication

Eyebars may be cast, forged, or cut from rolled plate. Casting is a manufacturing process by which a liquid material is (usually poured into a mold which Forging is the term for shaping metal by using localized compressive forces If round stock is used the eyes will usually be forged.

Heat treating

Heat treatment (heating and rapid cooling) will result in a fine-grained microscopic crystal structure, enhancing the strength of the bar. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. Excessive hardness may induce brittleness, which should be avoided.

The pins used to join bars will also be heat treated, usually to a degree of hardness exceeding that of the bars so that they will not shear under high stress.

Assembly

The bars may be fabricated with pin holes that are slightly undersized. If so, these are then reamed in the field. A reamer or ream is a tool used in Machining to make existing holes dimensionally more accurate and to improve surface finish This field reaming ensures that stresses will be uniformly distributed among the several bars forming the truss element or the chain link. Corrosion resistant treatment in the form of grease, white or red lead oil paste, or other water-excluding material may be added at the time of the assembly. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly