Flexural rigidity
Flexural rigidity is defined as the force couple required to bend a fixed non-rigid structure by one unit of curvature, or as the resistance offered by a structure while undergoing bending. == Flexural rigidity of a beam == Although the moment M ( x ) {\displaystyle M(x)} and displacement y {\displaystyle y} generally result from external loads and may vary along the length of the beam or rod, the flexural rigidity (defined as E I {\displaystyle EI} ) is a property of the beam itself and is generally constant for prismatic members.