Steel structure design steps

Steel structure design steps

(1) to determine whether the structure is suitable for steel structures
Steel structures are usually used in tall buildings, large span, complex shape, large load or crane weight, large vibration, required to be active or often assembled and disassembled. The buildings, the gymnasium, the opera house, the bridge, the TV Tower, the sculpture, the barn, the factory, the house, the mountain building and the temporary building. This is consistent with the characteristics of the steel structure itself.
 
(2) structure selection and structural arrangement
The steel structure is often framed, plane truss, truss (shell), film, light steel, tower mast structure.
Most of its theories and technologies are mature. Part of the problem is not solved, or there is no simple and practical design methods, such as the stability of the shell.
When the structure is selected, the characteristics of different structural forms should be considered. In industrial plants, when there is a large suspension load or a wide range of moving load, you can consider giving up the portal frame and the use of grid. Basic snow pressure big area, roof curve should be helpful for snow slide (tangent 50 degrees without considering the snow load), such as Ya Dong cement limestone shed the three circular shell, total snow load and slope roof release compared to nearly half. Areas with similar rainfall. In the building with large span, the cable or cable membrane structure is the most important component.
The structure layout according to the system characteristics, load distribution and properties of comprehensive consideration. The general said to uniform stiffness. The mechanical model is clear. Effects of possible restrictions on large load or moving load, the most direct line is transferred to the foundation. The distribution of inter column lateral support should be uniform. The center should be as close to the lateral force (wind, earthquake) line of action. Otherwise it should be considered. The lateral torsion of the structure should be multi line structure. For example, the frame structure, column should be at least 1/4 can handle the total horizontal force.
The floor of the frame structure of the secondary beam layout, and sometimes can adjust the direction of load transfer to meet different requirements. Usually in order to reduce the cross section along the short time to decorate beam, but it will make the girder section increase, reduce the floor height of the top edge of the pillar, sometimes too much, the beams of the main girder is short beam girder and keep sacrifice pillars.
 
(3) estimated cross section
At the end of the structure arrangement, it is necessary to make a preliminary estimation of the member section. The assumption of section shape and size of beam column and support.
Can choose the channel, steel rolling or welding H steel section. According to the situation of load and support, the section height is usually between 1/20~1/50. When the width of the flange is determined according to the l/b limit, the width of the lateral support between beams can avoid the complex calculation of the overall stability of the steel beam, which is very popular. The section height and the width of the flange, the plate thickness according to the provisions of local tectonic stability prediction.
The column cross section is estimated by slenderness ratio, usually 50< lambda < 150, the simple selection value is near to 80. According to the axial compression, biaxial bending or one-way bending different, can choose the steel pipe or H section steel and so on
In addition, there is no fixed requirement for the selection of the section form of the component, and the structural engineer should choose the safe and economical section according to the stress of the component.

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