There are usually two kinds of light steel structure: one is a skeleton structure composed of thin wall steel cold-rolled with thin steel plate (thickness below 6 mm); One is to use small section steel (such as Angle steel, steel bars, flat steel, etc.) to make trusses, and then compose a skeleton structure; There is also a skeleton structure composed of a mixture of the two methods. The wide use of thin-walled steel in the skeleton structures of automobiles, aircraft and ships has promoted the development of light steel structures in industrial system buildings. After the Second World War, CLASP and SEAC light steel structure school building systems appeared in Britain, and GEAJ and other light steel structure residential and office building systems appeared in France. Light steel structure buildings are light, easy to industrial production, fast and convenient construction and assembly, especially suitable for buildings requiring rapid construction and need to be moved, more used in schools, homes, offices, hotels, hospitals and factories and warehouses. It is necessary to remove the rust of silanized phosphating galvanized steel to improve the durability of later curing.

The structural form of light steel structure building is greatly affected by the traditional wooden frame building in Europe, which is often composed of thin wall steel or small section steel truss to replace the wall bars, joists and rafter frames of wooden buildings. The combination of the skeleton is generally related to the size of the building, the production method, the construction conditions and the transportation capacity. Common ones are:

The unit component building system consists of columns, wall bars, beams, joists, purlins, rafters and roof truss and other unit components assembled into a light steel structure skeleton, and then add roofing, installation of wall panels and doors and Windows. The joints of the skeleton are mostly fixed by bolts and plates. In order to strengthen the stability of the assembled skeleton, support or adjustable cross-type tie rods are added to the necessary parts. The building with the assembly of unit components has flexible assembly and convenient transportation, which can adapt to the needs of different building space combinations. However, the site construction time is longer than other installation methods.

Frame partition system A frame partition composed of thin-walled steel keels used as a load-bearing skeleton structure for walls, floors and roofs to assemble the entire building. The interior and exterior cladding and interior insulation, insulation, doors and Windows of such buildings can be installed during factory prefabrication or at the construction site after the skeleton has been assembled (Figure 1. This building system is like the plate assembly building, requiring fewer specifications and types of partitions and convenient node assembly. Since most of the work can be done in the factory, the quality is higher and the site construction speed is faster. The box composite building system is assembled into a room-sized box skeleton with thin-wall steel in the factory, complete the internal and external decoration and make the internal insulation layer, and even the interior decoration, including lamps, curtains, carpets, sanitation facilities, and even fixed furniture are installed in the factory. Transported to the construction site, as long as each box is hoisted and ready, the structure and waterproof treatment of the node are made, and the pipeline can be connected to use. In order to reduce the volume in transportation, some box units are made into foldable box components, transported to the site, opened during hoisting, and assembled (Figure 2). When assembling this combination method, attention should be paid to stability, as well as waterproof and thermal insulation treatment of the joints. Some can also be made into trailer type or container type mobile houses, easy to handle.