Due to its large application area, steel structure purlins are the primary components in purlin roof systems and truss structures. Therefore, the proportion of steel used in the structure of the house is also relatively large, so pay attention to the method of selecting purlins reasonably in the planning, and pay attention to the method of arranging the purlins in the steel layout.
One of the methods is to appropriately increase the purlin distance and reduce the weight of the roof. As far as the interception method of purlins is concerned, large-width purlins are usually divided into solid-belly, empty-belt, and tip-frame purlins. Usually 35~50 section width can be determined by section height h and selected steel specification. Commonly used are solid belly purlins and the span ratio of solid belly purlins.
Channel steel purlin
1. Due to the thick thickness of general channel steel, general channel steel and light-duty bad steel are often used as purlins. Most of them are designed for deflection control, and the strength cannot be fully exerted, so it has the defect of using a large amount of steel. The use of light-duty steel as purlins can improve the above shortcomings, but it is not perfect and has a thin web.
2. H-shaped steel purlins. High frequency welded H-section steel is a light-duty section steel. The bending stiffness is good, the moments of inertia in the directions of the two axes of symmetry are relatively close, the flanges are straightened, and they are easy to connect. It is a kind of bad wall section steel.
3. Crimping channel steel twist bar. Crimped bad steel is also called C-shaped steel. It is used as a purlin and has good interchangeability in us, and it is economical to use steel discs. It is suitable for extreme 1~1/3 conditions of the roof. At this moment, the effect line of the roof load is close to the bending center of its section. Crimped Z-shaped steel purlin main plane X uranium is large.
4. Rolled z-shaped steel purlins. There are two types of straight edge z-shaped and oblique edge z-shaped. The amount of steel is saved, and the selection of materials is convenient.
5. Angle steel purlins. Angle steel purlin is composed of single angle steel. However, the rigidity is suitable, and it is suitable for places with small span, purlin and street load.
6. Welded by two angle steel, combined with tip steel purlin. The amount of steel used for the combined stainless steel purlin is larger than that of the general channel steel, but the welding strength is small, and it is suitable for welding two pieces of angle steel with a span of 1~4m.
7. Combined Z-shaped steel purlins. The combined Z-shaped steel purlin is suitable for places with a roof slope of 1~1/3, and it is more reasonable than channel steel at this moment.
