design force for compression bracing member in braced steel frame

[XLSTL]

Hi, I have a question for how to determine seismic lateral force in a compression bracing member of braced steel frames.

My question is that I shall distribute how much portion of total design seismic lateral force to compression bracing member(s) when I design Chevron or inverted-V bracing system? AISC specification says that tension bracing member shall carry 30% to 70% total design lateral force, but it does not specify compression bracing member. Is this force distribution open to the judgement? What is common design practice on this issue? Thanks for help!

 

[wannabeSE]

The force on a line is typically distributed proportional to the stiffness of the braces.

 

[KootK]

The 30/70 business isn't a load assignment, it's a criterion that has to be met. If your structure meets it then, by definition, your compression members will also attract 30 to 70 percent of the load.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[XLSTL]

Thanks both for help!

 

[KootK]

This would be an excellent document for you to have if you don't already: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[XLSTL]

Great! Thanks, KootK.