Featured Articles

What is a shear key in steel structures?

-
图片
 In steel structure engineering , the column base connection serves as the pivotal interface linking the superstructure to the concrete foundation below. It must safely and reliably transmit various loads from the upper structure: vertical pressure , uplift forces , bending moments , and horizontal shear forces . When horizontal shear forces become substantial, the friction alone between the column base plate and the concrete foundation surface proves insufficient to resist them. At this juncture, a critical small component becomes indispensable—the shear key . Shear keys, as the name suggests, are structural steel connection components specifically designed to resist and transmit horizontal shear forces. Essentially, they are short steel members. Installation location: Typically welded or anchored to the base plate of a steel column (or other load-bearing components such as equipment supports ), with its lower end embedded in the concrete foundation or concrete structure cast ...
发表评论

Welded ball processing method

-

 

Welded ball

Hot press moulding method

Unloading: according to the design requirements, adopt semi-automatic gas cutting, profiling gas cutting, CNC flame gas cutting and other methods to unload the steel plate and cut out the round plate of suitable size, when unloading, it is necessary to reserve the welding shrinkage margin for fabrication and installation as well as the machining margins for cutting, edge planing, milling and so on.

Heating: The blanks are heated uniformly to about 1050°C±50°C in a reflector furnace or resistance furnace after unloading.

Pressing and moulding: Use hydraulic presses and matching convex and concave moulds to press and mould the heated slabs to produce hemispherical shapes. The demoulding temperature should not be lower than 650°C. After the hemisphere is pressed and moulded, the wall thickness should be reduced by not more than 13% and not more than 2.5mm according to the design and specification.

Cutting bevel margin: can be processed on the machine tool or use semi-automatic flame cutting machine to cut the hemisphere, remove the bevel margin, so that the bevel does not leave roots, in order to weld through.

Assembly of two hemispheres and added ribs: when there are stiffening ribs, the rib plate is suitable to use semi-automatic cutting machine or CNC cutting machine for undercutting, and the outer diameter should be reserved for machining allowance. The two hemispheres and the reinforcing rib plate are assembled on the special ball assembly tyre frame, and the shrinkage of the weld should be left when assembling to ensure that the size and roundness of the finished hollow ball after welding are achieved.

Welding: use carbon dioxide gas shielded welding, semi-automatic submerged arc welding machine for multi-layer multi-channel welding of the sphere, until the weld channel welded flat. When welding, it is necessary to rotate the sphere and adjust the welding channel, wire height and welding parameters.

Flaw detection: After the weld passes the appearance inspection, ultrasonic flaw detection is carried out on the ball weld after 24h to ensure that the internal quality of the weld meets the requirements.

Shaping and anticorrosion treatment: Shape the ball after welding, make its surface smooth and flat, no corrugation, local unevenness is not more than 1.0mm, the height of the weld and the outer surface of the ball is flush with the deviation of not more than ±0.5mm, and then carry out the descaling and anticorrosion treatment, such as spraying inorganic zinc-rich zinc coating of alcohol-soluble ethyl orthosilicate.

评论

发表评论

此博客中的热门博文

What is a coal bunker?

-
图片
Coal bunker , is a structure used for storing coal. Coal bunkers play an important role in thermal power plants, coal mines and coal marshalling stations. Depending on the specific application scenario and design, there are various types of coal bunkers, such as circular coal bunkers, square coal bunkers and open coal yards. Safety Management of coal bunkers Preventing spontaneous combustion of coal: Since coal itself contains certain moisture and volatile substances, long-term exposure to the air may lead to spontaneous combustion, so the safe management of coal bunkers is of great significance in preventing spontaneous combustion of coal. Ensure the quality of coal: coal in the coal bunker usually needs to be stored for a long time, if not managed properly, it may lead to the decline in the quality of coal, such as sulphurisation, weathering and other phenomena, so it is necessary to ensure the quality of coal by strengthening the safety management of the coal bunker. Improve the eco...
阅读全文

Suspension structures

-
图片
 A suspension structure is a structural form that carries roof loads through a series of high-strength steel cables. Its main load-bearing member is the cables, which are usually steel cables made of high-strength steel wires. The roof of the suspension structure is generally light and thin, and its shape can be very flexible, able to realize the large span across. For example, in the roofs of some large conference centers or exhibition halls, the suspension structure can create unique shapes such as double-curved paraboloid or single-curved paraboloid, which make the building have a strong artistic influence. Suspension structures require a stable support structure to anchor the steel cables, usually using reinforced concrete columns or steel columns as support. And in order to ensure the stability of the structure, it is also necessary to set a certain amount of prestressing, so that the steel cables are in a tensioned state before they are subjected to loads. Scope of applicatio...
阅读全文

What is the difference between a single-layer reticulated shell and a double-layerreticulated shell?

-
图片
  The differences between single-layer reticulated shells and double-layer reticulated shells are as follows: Structural Configuration   Single-layer reticulated shell: Composed of a single layer of members, with the members directly connected to form a grid structure . The node configuration is relatively simple, typically employing rigid connections that allow the members to bear not only axial forces but also bending moments and shear forces.   Double-layer reticulated shell: Consists of upper and lower parallel layers of members connected by web members, forming a truss-like structural system. The nodes are generally hinged, and the members primarily bear axial forces. Its configuration is relatively complex, requiring more members and nodes to ensure structural stability and load-bearing capacity. Structure Single-layer mesh shell: composed of one layer of rods, the rods are directly connected to form a mesh structure, the node structure is relatively simple, usually...
阅读全文