The expression for crippling load (P) when both end of the column are hinged is given by:
Where l = actual length of column, E = Youngs Modulus of elasticity; I = Moment of Inertia
1
\(P=\frac{EI\pi^2}{4l^2}\)
2
\(P=\frac{4EI\pi^2}{l^2}\)
3
\(P=\frac{2EI\pi^2}{l^2}\)
4
\(P=\frac{EI\pi^2}{l^2}\)