Steel structure is a type of building structure with steel as the main material. It has the advantages of high strength, light weight, high stiffness, good shock resistance, fast construction, etc., and is widely used in industrial, civil, bridge, sports venues and other fields. The structural forms of steel structure are mainly as follows:

Portal rigid frame: Portal rigid frame is a flat rigid frame composed of steel columns and steel beams, which can form a single span or multi-span space structure. It is suitable for plants, warehouses, workshops and other buildings with small spans. The portal rigid frame has the advantages of simple force, clear force transmission path, fast construction speed and economical application.

Steel frame: Steel frame is a kind of space rigid frame composed of steel columns and steel beams, which can form a multi-storey or high-rise space structure. It is suitable for buildings with large span or high height, such as office buildings, shopping malls, hotels, conference centers and so on. The plane layout of the steel frame is flexible, which can form a large space, but the requirements of resistance to side forces also need to be considered.

Steel truss: Steel truss is a space structure composed of a number of members according to certain rules. It can use rods with smaller sections to compose components with larger sections, which is suitable for buildings with larger spans or higher heights, such as stadiums, exhibition halls, hangars, TV towers, etc. The steel truss is light in weight and high in stiffness, but it is also necessary to consider the problems of stability and connection mode.

Steel grid: Steel grid is a spatial structure composed of a number of rods connected by nodes in accordance with a certain grid form. It can form complex curved or curved shapes and is suitable for buildings with roofs or walls, such as waiting halls, awnings, domes, etc. The space force of the steel grid is small and the seismic resistance is good, but the design and production of nodes also need to be considered.