Buckling Occurs At The Critical Bending Moment

If a structure is subjected to a gradually increasing load, when the load reaches a critical level,

a member may suddenly change shape and the structure and component is said to have buckled.

For a simply supported beam of rectangular cross section subjected to uniform bending, buckling occurs at the critical bending moment,given by

where ,

L unbraced length of the member

E modulus of elasticity

Iy moment of inertial about minor axis

G shear modulus of elasticity

J torsional constant