1This material has high strength and light weight.

        Steel has high strength and elastic modulus.Compared with concrete and wood, the ratio of density to yield strength is relatively low.Therefore, under the same stress state, the steel structure component has small section and light weight, which is convenient for transportation and installation, and is suitable for large span, high height and heavy load structure.

2The steel has good ductility, good plasticity, uniform material and high reliability.

        It is suitable for bearing impact and dynamic load with good seismic performance.The internal structure of the steel is homogeneous, close to the isotropic homogeneous body.The actual working performance of the steel structure accords with the calculation theory.Therefore, the reliability of steel structure is high.

3Steel structure manufacturing and installation is highly mechanized

steel structure design components are easy to assemble in factories and construction sites.The mechanical steel structure of our factory has high precision, high production efficiency, fast assembly speed and short working cycle.Steel structure is the most industrialized structure.

4The sealing performance of steel structure is good.

        Because the welding structure can be completely sealed, it can adopt air tightness, high pressure vessel, good water tightness, large oil pool, pressure pipeline, etc.

5Heat resistant and non fire resistant steel structure

         When the temperature is lower than 150 ℃, the properties of the steel change little.Therefore, the steel structure is suitable for the hot workshop, but the heat radiation on the surface of the structure is about 150 ℃, so the heat insulation board should be used to protect it.When the temperature is 300-400 ℃, the strength and elastic modulus of the steel decrease significantly.When the temperature is about 600 ℃, the strength of steel tends to zero.In buildings with special fire protection requirements, steel structures must be protected with refractory materials to improve the fire resistance rating.

6The corrosion resistance of steel structure is poor.

         It is easy to rust in humid environment.In general, steel structures shall be derusted, galvanized or coated and shall be maintained regularly.Special measures such as “zinc block protection” should be taken to prevent the corrosion of offshore platform structure in seawater.

         steel structure design is to serve the construction and use of steel structure.The purpose of steel structure engineering is to create benefits.Public buildings are more important than social benefits, while industrial buildings are more important than economic benefits.Therefore, steel structure economy is another important aspect of steel structure design.The principle of “economic structure of steel structure” should be analyzed comprehensively and should not be investigated in isolation.Comprehensive evaluation of structural system rationality should be considered for light steel portal frame structure.Steel consumption, processing and manufacturing cost, installation cost, construction period and basic cost should be considered comprehensively.Therefore, in the design of steel structure, it is necessary to conduct in-depth analysis and comprehensive research on the economy of steel structure system.Only the best comprehensive scheme or steel structure system is reasonable.