Flexure Formula

Flexure Formula
Stresses caused by the bending moment are known as flexural or bending stresses. Consider a beam to be loaded as shown.
 

Flexure of a beam

 

Consider a fiber at a distance $y$ from the neutral axis, because of the beam's curvature, as the effect of bending moment, the fiber is stretched by an amount of $cd$. Since the curvature of the beam is very small, $bcd$ and $Oba$ are considered as similar triangles. The strain on this fiber is