threaded rod load limits 3

[howwee]

what would be the approximate vetical drop suspended load limit of a 4' span 5/8" standerd threaded rod

 

[LPPE]

Look in your AISC design manual under Connections. There are load tables for threaded rods.

 

[dougantholz]

Howee,
The design strength for an A36 5/8 in dia threaded rod (in LRFD) is
PHI*Rn = .75*Fu*Ag
Ag is the gross area (0.31in^2)
Fu is the ultimate strength (58 ksi for A36)
The result is an ultimate load. The elongation is approx. 1/16th of an inch. The design equation can be found on pg 8-89 of AISC's Load and Resistance Factor Design, Vol II.
Hope this helps

 

[StructuralDzine]

Members are designed using their yield strength while connections are designed using their ultimate strength. A threaded rod in this application would be considered a member rather than a connection. Yield in a connection is not the most important limit state and is often an advantage because it allows redistribution of load within the connection.
In limit state design the capacity would be:
crf*fy*As
crf=capacity reduction factor(partial safety factor) appropriate to your code.
There was an article on this earlier this year in the e-newsletter Structural Dzine.

 

[phuduhudu]

StructuralDzine,

Well...why not let us know how we can subscribe to this e-newsletter? Sounds good.
Carl Bauer

http://www.bauerconsultbotswana.com

 

[StructuralDzine]

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The issue on strength of rods was
Structural D-zine, April 01