Question

A steel column pinned at both ends has a bucking load of 160 kN. If the column is effectively held in position and restrained against rotation at one end but neither held in position nor restrained against rotation at the other end, then its bucking load will be kN.

• A. 40

Answer 1

The correct option is A 40

The buckling load of a steel column pinned at both ends is,
$P_1=\frac{{\pi }^{2}EI}{l_{eff}^2}=\frac{{\pi }^{2}EI}{l^2}=160kN$
When the column is effectivley held in position and restrained against rotation at one end and the other end is free then
$I_{eff}=2l$
$\therefore P_2=\frac{{\pi }^{2}EI}{(2l{)}^2}=\frac{1}{4}\times 160=40kN$