H-beam knowledge

I-shaped steel, whether ordinary or lightweight, has relatively high and narrow cross-sectional dimensions, resulting in a significant difference in the moment of inertia between the two main sleeves of the cross-section. Therefore, it can generally only be directly used for components that are bent in the plane of its web or to form a lattice load-bearing component. It is not suitable to use axial compression components or components with bending perpendicular to the web plane, which limits their application range.

H-shaped steel belongs to the category of economical section profiles (including cold-formed thin-walled steel, profiled steel plates, etc.). Due to their reasonable cross-sectional shape, they can enhance the efficiency of the steel and improve its load-bearing capacity. Unlike ordinary I-beams, the flange of H-beams has been widened, and the inner and outer surfaces are usually parallel, making it easier to connect with high-strength bolts and other components. Its size composition series is reasonable, and the models are complete, making it easy to design and choose.

The flanges of H-shaped steel are of equal thickness, with rolled sections and composite sections composed of three plates connected. I-beams are all rolled sections, and due to poor production technology, there is a 1:10 slope on the inner edge of the flange. The rolling of H-beam steel is different from ordinary I-beam steel, which only uses one set of horizontal rollers. Due to its wide flange and no slope (or very small slope), it is necessary to add a set of vertical rollers for rolling at the same time. Therefore, its rolling process and equipment are more complex than ordinary rolling mills. The height of rolled H-beams that can be produced domestically is 800mm, which can only be used for connecting composite sections. The national standard for hot-rolled H-beams in China (GB/T11263-1998) divides H-beams into three categories: narrow flanges, wide flanges, and steel piles, with codes hk and hu, respectively. Narrow flange H-shaped steel is suitable for beams or compression bending components, while wide flange H-shaped steel and H-shaped steel piles are suitable for axial compression or compression bending components. Compared with H-shaped steel, I-shaped steel is inferior in terms of w, ix, and iy under equal weight conditions.

◆ Flexible and rich design style: With the same beam height, the steel structure bay can be 50% larger than the concrete structure bay, making the building layout more flexible.

High structural stability: Steel structures mainly made of hot-rolled H-beams have scientific and reasonable structure, good plasticity and flexibility, high structural stability, and are suitable for building structures that withstand large vibration and impact loads. They have strong resistance to natural disasters, and are particularly suitable for building structures with multiple vibration zones. According to statistics, among the devastating earthquake disasters with a magnitude of 7 or higher in the world, steel structures mainly composed of H-beams have a relatively low degree of damage.

◆ Labor and material saving: Compared with connecting H-shaped steel, it can significantly save labor and material, reduce the consumption of raw materials, energy, and labor, reduce residual stress, and have good appearance and surface quality.

◆ Environmental protection: The use of H-shaped steel can protect the environment, which is manifested in three aspects: firstly, compared to concrete, dry construction can be used, resulting in less noise and dust; Secondly, due to the reduction of self weight, the amount of soil taken for foundation construction is small, which causes little damage to land resources. In addition, a significant reduction in concrete usage and the amount of rock excavation is beneficial for environmental protection; Thirdly, after the service life of the building structure expires, the amount of solid waste generated after the structure is dismantled is small, and the recycling value of scrap steel resources is high.