ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
In the portal steel structure factory building, there will be some technical problems, such as purlin problems, enclosure system problems and so on. Today we will talk about the role of steel structure factory roof skin.
1. [Skin effect can improve bearing capacity]
For roof purlin, Xia Yiyuan's code for checking thin-walled steel under the action of analytical force does not consider the role of slander skin. The calculation results are very uneconomical. Many experts at home and abroad are studying this problem. The effect of skin can greatly improve the bearing capacity of portal frame. In addition, the effect of roof skin has a great influence on the bearing capacity of purlin lower flange instability. In some places, the effect of roof skin is considered when purlin lower flange instability occurs, but it is not mature at present.
2. [Roof skin can affect purlin bearing capacity]
The shear resistance of the roof skin of coloured steel plate in steel structure factory building is not a problem for purlin upper flange to provide lateral support. When the Q value of the roof shear capacity reaches a certain value, it will only increase, which will not cause obvious changes in the two bearing capacity. The roof shear capacity can generally meet this requirement. Therefore, the roof skin effect is an important factor affecting the purlin bearing capacity for the buckling restraint of the lower flange of purlin.
3. [Roof skins stabilize the plane of portal frames]
The effect of roof skin can also be used for out-of-plane stability of portal frames. That is to say, when calculating out-of-plane stability, the out-of-plane fulcrum of portal frames can adopt the spacing between purlins rather than the spacing between horizontal supports. Because of this assumption, different programs will have different calculation results. The skin effect of wallboard is also discussed. At present, when foreign design is strong, self-weight is not taken into account, and no stretching is relatively simple. Therefore, the skin effect of the wall can be considered, but it is absolutely impossible to omit the support between columns, and the support between columns is better not to use round steel to set up.