Column Buckling & Struts

What am I seeing?

• Euler buckling load is π²EI/(kL)²: the end conditions set k and change the capacity fourfold or more.
• Slender columns fail by buckling on the Euler curve; short columns squash at the yield stress.
• The changeover slenderness is where the Euler stress equals fy.
• Watch the buckled shape change as you switch the end conditions.