AISC 2005 Spec - Chapter Section H1.3 1

[starcasm]

I am having some trouble understanding how to apply Chapter Section H1.3 Doubly Symmetric Members in Single Axis Flexure and Compression. Below is my interpretation of that section. I could not find this section used in an example so I will provide some paremeters and my interpretation of what formulas apply. Could someone point me in the right direction if I am wrong?

Say we have a...
W12x58
Pr = some number
Mrx = some number
Mry = 0

I see this as having to satisfy...

In-plane Instability:
EITHER (Pr/Pc)+(8/9)*(Mrx/Mcx) <= 1.0 (H1-1a)

OR (Pr/2*Pc)+(Mrx/Mcx) <= 1.0 (H1-1b)

Out-of-plane Buckling (Flexural-Torsional Buckling):
AND (Pr/Pco)+(Mr/Mcx)^2 <= 1.0 (H1-2)

Is that right? And if so, what if we have a...
W12x58
Pr = some number
Mry = some number
Mrx = 0

I see this as having to satisfy...

In-plane Instability:
EITHER (Pr/Pc)+(8/9)*(Mry/Mcy) <= 1.0 (H1-1a)

OR (Pr/2*Pc)+(Mry/Mcy) <= 1.0 (H1-1b)

Out-of-plane Buckling (Flexural-Torsional Buckling):
AND (Pr/Pco)+ 0 <= 1.0 (H1-2)

I understand that the bulk of the work is determining Pc, Mcx, and Mcy.

Thank you in advance,
Daniel...

 

[JAE]

Looks correct to me.

However, your first term of Equation H1-1b should read:

(Pr/(2*Pc))

The way you wrote it reads as though you have (Pr x Pc)/2 if you use computer/spreadsheet logic.

 

[starcasm]

My bad... That's what I meant to do. Thank you very much for the response. Star for you!