Flange bracing and diaphragm bracing are two types of bracing solutions sufficient for metal buildings below 60 feet wide. But for reasons such as unusual higher loadings for wind and snow, presence of lift caused by a large number of framed openings and building width greater than 60 feet, installation of additional bracing is a must.
These are other types of bracing solutions for metal buildings:
X Bracing. Steel rods or cables are installed to tightly connect the steel frame of metal buildings, especially those located in areas frequently experiencing heavy snow and high winds. The X bracing has proven to be the most economical among all bracing solutions for metal buildings.
Weak Axis Bending. By increasing the size of the base plates, weak axis bending is used for metal buildings that require heavy loads on the column. This prevents the columns from moving under heavy stress.
Wind column. In cases where the X bracing is still not enough or when it interferes with framed openings or when weak axis bending does not provide stability to the columns, a wind column is used instead. A wind column is the next most economical bracing solution for metal buildings. Basically, it is an I-beam that is bolted to the main frame and the foundation to provide additional strength and stability.
Portal Frame. In extreme load circumstances when the above bracing solutions are still not enough, a secondary rigid frame is used. Portal frames are characterized by two columns and a rafter and placed between two primary rigid frames in a bay. This is an expensive bracing solution so it is rarely used unless it is really necessary. When a framed opening prevents an X bracing solution, a portal frame is used instead.
Metal buildings come with standard bracing solutions to provide stability against the pressures caused by the existing loads brought about by natural forces and the structure’s design.
Metal buildings are viable solutions for just about any construction need, be it industrial, commercial and even residential. Their widespread use has been mostly due to their fast and efficient construction and the unmatched durability and reliability they provide. The secret to the strength of metal buildings is in their steel framing and bracing.
Prefabricated metal building packages may vary from supplier to supplier but most of them come with standard features that include the primary framing, secondary framing and the bracing.
Metal buildings are computer-engineered and manufactured at the factory, with all frame members fabricated for easy assembly at the site. Through the use of the accompanying erection manual, properly marked building components (for easy identification) are fitted together to form the building skeleton where the roof and walls are attached.
The backbone of any metal building is the main frame – made of solid steel I beam, it takes most of the load. Common secondary framing members for metal buildings include girts (for walls), purlins (for the roof) and eave struts. The primary and secondary framings provide an extremely rigid support for the whole structure to meet the loading requirements of the area.
However, some metal buildings located in areas with greater loadings for wind, seismic and snow, may require additional reinforcement. To make metal buildings more stable and stand the pressures brought about by torsion, lift, compression, tension and shear, different types of bracing are included in their design.
Flange bracing and diaphragm bracing are standard bracings for metal buildings. Made up of structural angles and connected between the rafters and the purlins, the flange bracing prevents the rafters from sideways movement. On the other hand, the roof panels and wall panels are actually some kind of reinforcement to metal buildings by acting as a “diaphragm” or membrane that pulls the structure together.
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