Interaction curve(4-point) for filled composite columns-Any example? 3

[IJR]

Pals

The code suggests creating interaction curve (4 points A,B,C and D)

I have trouble creating these points for a circular filled column. Should be circular

Anyone knows of a good reference or a web site.

respects
IJR

 

[jdonville]

IJR,

The interaction diagram will not necessarily be circular (RC circular column diagrams are not circular). You should be able to create the unfactored diagram based on trial and error using allowable stresses, say using Excel.

You may want to see

http://stommel.tamu.edu/~esandt/Teach/Summer03/CVEN444/Lecture/Lecture20/lecture20.ppt

for a discussion and some instructions (slides 38-50).

Jeff

 

[IJR]

jdonville

Thanks for the link

I didnt mean a "circular interaction" diagram. I meant interaction diagram for a "circular column". I need plastic moment and axial capacities at the 4-points mentioned in AISC'05.

The expressions is what I am looking for

respects
IJR

 

[WillisV]

The equations you seek are located on the companion CD to the 13th ed. manual. Look in design examples for Chapter I on this CD. The figure containing equations for the interaction points for filled circular columns is Figure I-1d.

 

[IJR]

Yes WillisV

A friend of mine gave me those equations.

But if you use the equation you will see that theta value comes too large. Try any column size.

Either the formula is wrong or I am missing something, probably the later.

respects
IJR