Features of straight seam steel pipe

(1) The geometric properties of the straight seam steel pipe section are good, the pipe wall is generally thin, the section material is distributed around the center of mass, the section gyration radius is large, and the torsional rigidity is large; as a compression, bending and bidirectional bending member, its bearing capacity is high, and The straightness and cross-sectional dimensions of cold-formed tubes are more precise than the cross-sections of hot-rolled openings.

(2) In terms of anti-hydrodynamic properties, the cross section of the round tube is the best, and the flow effect of wind and water is greatly reduced. The cross-section of a rectangular tube is similar in this respect.

(3) The steel pipe is a closed section; under the same average thickness and cross-sectional area, the exposed surface area is about 50% to 60% of the open part, which is beneficial to prevent corrosion and save paint.

(4) The connection of the node is suitable for direct welding, which can save labor and material without passing through the gusset or other connecting parts.

(5) The appearance is relatively beautiful, especially the pipe frame composed of steel pipes, without redundant node connections, has a strong modern sense.

(6) If necessary, concrete can be poured into the pipe to form a composite member.

Due to the above advantages, steel tube structures can save about 20% of steel in industrial buildings and about 50% of steel in tower structures compared to structures made with open sections. According to the force state of the parts, supply conditions, production and processing conditions and costs, the structure of the steel pipe can be a round pipe structure or a rectangular pipe structure, or a mixture of two steel pipes. When used in combination, the chord is generally a rectangular tube, and the web is a circular tube. Sometimes, the chords can also be made of I-beams or H-beams, and the ribs can be rectangular or round tubes.

When the mechanical properties are stable, local buckling is prone to occur when pressure is applied, but post-buckling strength and hydrodynamic resistance are most beneficial. The minimum force is the same, the surface area is the smallest, and the surface area is slightly larger. There are anti-corrosion, fire-proof, cornerless anti-corrosion, fire prevention at the corners of the school; more materials are used for fire-resistant and anti-corrosion materials.