What's the usefulness of maximum stress calculated on Secant's formula for buckling?

For comparison: in Euler's formula, we calculate the critical force such that when the column is subjected to it, it buckles. As far as I understand, the yield strenght of the material doesn't really matter.

However, when facing eccentric load, secant formula is used and a maximum strain is calculated, instead of a critical force. Does it makes sense then to use yield strength as a maximum admissible strength?

Edit: also, when derivating the formula for the maximum strain, one already considers the compressible strain and the bending combined. Thus, when calculating the maximum strain, I don't need to further make any considerations about their interations, correct?

• If you are clmbing a ladder, would you want someone to have calculated the buckling loads correctly? Commented Feb 7, 2020 at 15:23
• Sure. I don't know if my question wasn't clear: Im trying to understand the correct methodology to calculate a column under axial force, not to ignore it. Commented Feb 7, 2020 at 16:45

We need to check the column for both the maximum stress with the secant formula and critical buckling load if the eccentricity is small and the column is slender and tall. As we know critical buckling load in medium and short columns gives wrong, over the yield strength results, so we always check for P/A< (allowable stress) too.

The secant formula already calculates the maximum stress under the combination of the axial load and moment stress due to the bending of the column.

• Thanks, kamran. You seem to have confirmed my thoughts Commented Feb 11, 2020 at 10:53