Truss is widely used in steel structure, such as in industrial and civil building’s roof (roof truss, etc.) and crane beam (crane truss), bridge, crane (tower, beam or boom, etc.), hydraulic gate, offshore oil platform, steel truss is commonly used as the main component of load-bearing structure. In the roof structure of large-span public buildings, various types of steel grids are commonly used, which belong to space steel truss. Various types of tower, such as TV, power transmission, drilling, crane tower and mast tower, commonly use three, four or more plane truss space steel truss.

The most commonly used is plane truss, which is essentially lattice beam under transverse load. Compared with solid web steel beam, steel truss is characterized by chord instead of flange and web bars instead of web plates and web and chord are connected with each other through gusset plate (or other parts) with weld or other connection; Sometimes, the members can be directly welded (or other connected) to each other without gusset plates. In this way, the bending moment of the plane truss is expressed as the axial compression and tension of the upper and lower chords, and the shear force is expressed as the axial compression or tension of the web members. Steel truss is a truss made of steel. Steel truss is used as the main load-bearing component in the roof structure, crane beam, bridge and hydraulic gate of industrial and civil buildings.