Calculating Deflection and Buckling in L-Shaped Square Tubing Legs

[ksukhin]

I need to know how big of a radius I need to use on an L shaped leg made out of square tubing. Is there a general formula depending on the length and height required?

How would I calculate the deflection at the end and the buckling on the vertical part?

For the deflection part, would I ignore the vertical component of the leg and assume that the end is fixed, and just deal with the horizontal part of the L shape?

For buckling on the vertical part, how do I account for the moment created from the load on the end?

 

[SteamKing]

These are pretty specific questions about a situation which is otherwise only vaguely described. More information is required about the intended purpose of this structure and the loads applied to it.