What is called economic section steel, explain it specifically Thank you

There are many types of steel, which can generally be classified into four categories: profile, plate, tube and wire. 1. There are many varieties of section steel, which is a kind of solid strip steel with a certain cross-sectional shape and size. According to the different cross-sectional shapes, it is divided into two types: simple and complex cross-sections.

The former includes round bars, square bars, flat bars, hexagonal bars and angle bars; The latter includes rails, I-beams, channel steels, window frame steels and special-shaped steels. The diameter of the small round steel is called the wire. 2. Steel plates are divided into three types: thin plate (thickness <4mn), medium plate (thickness 4-25mn) and thick plate (thickness 25mm) according to different thicknesses.

3. Steel pipe This is a kind of long steel with hollow section. According to its different cross-sectional shapes, it can be divided into round pipes, square pipes, hexagonal pipes and various special-shaped cross-section steel pipes. According to different processing technology, it can be divided into two categories: seamless steel pipe and welded steel pipe.

When you use steel, you only need structure and appearance and do not need strength, you can choose the economical type, that is, the cross-sectional area is slightly smaller, also called the economic cross-section. The exterior dimensions remain unchanged. Does that make sense?

It can be understood as structural steel.

Including, H-beam, T-beam, special-shaped steel, steel pipe and cold-formed type.

Steel, profiled plates, etc. Due to the reasonable shape of the cross-section, it is cut in an environment where the amount of steel is commensurate.

The surface moment of inertia can be larger than that of a normal cross-sectional profile.

Surface area = section side length 10cm x length 80cm = 800 square cmx4 = 3200 square centimeters + area of two sections: 10cmx10cmx2 total = 3400 square centimeters. Weight = cross-sectional area 10cmx10cmx length: 8 m x 10x gravity gram = 62,400 grams = kilogram.

This refers to the cross-section classification of the axial strut. In engineering, the relationship between the overall stability coefficient and the slenderness ratio of the compression rod is called the column curve.

In the Code for the Design of Steel Structures, the maximum strength criterion is adopted, and a large number of column curves, that is, lines, are calculated according to different cross-sectional dimensions and residual stress modes.

Taking into account the different forms, sizes and different processing conditions of the cross-sections, the axial compression members of different cross-sections are classified. The cross-section with similar bearing capacity and the corresponding axis of bending instability are combined into one category, which are summarized into three categories: A, B and C, and special provisions are made for the I-shaped and H-shaped sections that make up the plate T 40mm, and the class D cross-section is added.

Steel has high strength and high modulus of elasticity. Compared with concrete and wood, the ratio of its density to yield strength is relatively low, so the component section of the steel structure is small under the same stress conditions, the self-weight is light, it is convenient for transportation and installation, and it is suitable for the structure with large span, high height and heavy load.

The steel has good toughness, good plasticity, uniform material and high structural reliability. It is suitable for bearing impact and dynamic loads, and has good seismic performance. The internal structure of the steel is uniform, which is close to the isotropic homogeneous body.

The actual working performance of the steel structure is more in line with the calculation theory. Therefore, the steel structure has high reliability.

These grades represent the material and type of steel. You'll know each grade at once.

It's not just about knowing how to read them, but also about the content of the ingredients inside

It's the geometric dimensions and the associated moments, and then it's the ductility, the pressure, the natural deformation.

That's how I understand it, and I don't know if it's right.

Depending on the content of various elements, especially the C content, there are also some impurities.

It is the residual stress of the factory during processing.

1."The diameter of the configured upper co-directional longitudinal bar should be combined. Combined with the diameter and spacing this is a design problem, we according to the drawing construction, but the requirement of "every cloth one" is that the spacing of the through ribs and the spacing of the non-through ribs should be the same, so that the non-through ribs can be placed in the middle of the through ribs, as for the diameter of how to consider I don't know;

2."When the through-bar is set to 50% of the total cross-sectional area of the longitudinal bar, the two types of reinforcement take the same diameter" - is this difficult to understand? Since it is a cloth every other cloth, so the number of through ribs is the same as the number of non-through simple old ribs, since the number of roots is 50%, the diameter must be the same, if the diameter of the through rib is large, the total cross-sectional area must be large, otherwise the opposite.

3.The method of "every other is not the same" is as shown in the following figure, a simple board is drawn, the red one is the through bar, and the yellow one is the non-through bar, which is also called the negative bar of the loose plate, or the additional steel bar.

Deep drawing is actually just a concept, generally speaking, the grade SPCD, BLD, DC03 is deep drawing, in addition to ultra-deep drawing materials, etc., depending on your personal requirements, this is just a change, the key is that the product and the material match, so that it saves costs and does not waste materials.

The force in the direction of the weak axis is less than that of the strong axis, so in the structure, the area distribution of the material in the direction of the weak axis will be reduced, and the material distribution will be seen on both sides of the web. The first person to answer was also right.

A section has two perpendicular shafts, the shaft with a large flexural modulus is called a strong shaft, and the other is a weak shaft.

The cross-section you are talking about may be an H-beam, and generally speaking, the axis parallel to the flange plate is a strong axis.

According to the side steel column (H-shaped steel), the direction parallel to the flange plate is the strong axis direction, and the direction perpendicular to the flange plate is the weak axis direction.

The direction of the large resistance moment of the cross-section is the direction of the strong axis, and the other direction is the direction of the weak axis.

For the H-shaped section commonly used in construction, see the figure below, the direction around the X-axis is the direction of the strong axis, and the direction around the Y-axis is the direction of the weak axis.

Here's exactly the opposite.