portal frame bracing

[mrh58]

I usually use CHS or SHS as bracings in our portal frame buildings, i would like to explore using crossed angles and/or crossed flats. are there any pitfalls i should be aware of?

 

[rowingengineer]

1. Angles and rods don't take compression,
2. angles and rods have limited spans that can travel before deflection become an issue (to solve this you can hang from the purlins)
3. I prefer rods over angles due to the ability to have a turnbuckle for installation.
4. getting angles to the right length such that they are installed correctly is hard. often they are too long this causes a compression that needs to be taken up before they can be used as the tension tie.


Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that they like it

 

[csd72]

The way angles are connected at the ends means that they do not have a uniform stress distribution and this needs to be taken into account in your design.