Calculate column critical buckling load using Euler's formula with end condition factors.
K accounts for how column ends are supported. K=0.5 (both ends fixed) is strongest. K=0.7 (one fixed, one pinned). K=1.0 (both pinned). K=2.0 (one fixed, one free — cantilever) is weakest. Lower K means higher critical load.
Euler's formula applies to long, slender columns that fail by elastic buckling (slenderness ratio > ~100). Short, thick columns fail by material yielding, not buckling. For intermediate columns, use Johnson's formula or applicable design codes.