Neutral axis
= Neutral axis
{wiki}
The <neutral axis> is the line in the cross-section of an <elastic beam> where longitudinal bending <strain> vanishes. For a homogeneous beam in pure bending, zero resultant longitudinal <force> gives $\int_Az\,dA=0$, so the <neutral axis> passes through the <centroid>. Fibres on its opposite sides are stretched and compressed. The <second moment of area> about this axis controls the relation between <bending moment> and <curvature>.