Truss is section or space structure composed with triangle unit by straight pole.Under effect of loading,truss pole unit mainly bears axial tension and pressure to fully utilize strength of materials.It would be more material saving than solid web girder when in great span,reducing self weight and enlarging stiffness,is suitable for support structure and towering structure with great span.
Truss in the truss structure refers to the truss beam,which is a kind of beam type structure.Truss structures are commonly used in large-span buildings,exhibition halls,stadiums,bridges and other public buildings.Because most are used for roof structure of the building,also known as the roof truss.Now truss srtucture has varied forms,is not limited to the roof.In some big span structure,high-rise buildings,bridges has a very wide range of applications.
Truss are classified with:
(1)Parallel chord truss:easy to arrange the double layer structure,which is conducive to the standardization of production,but the bar force distribution is not uniform enough;
(2)Cruved chord truss:such as parabolic truss beam,shape wuth uniformly distributed load bending moment of a simply supported beam,rod force uniform distribution,material the use of economic,the structure is more complex;
(3)Triangle truss:the distribution of the rod is more uneven,the structure is difficult,but the slope meets the needs of the roof drainage.