Bending stiffness

The bending stiffness (${\displaystyle K}$) is the resistance of a member against bending deformation. It is a function of elastic modulus ${\displaystyle E}$, the area moment of inertia ${\displaystyle I}$ of the beam cross-section about the axis of interest, length of the beam and beam boundary condition. Bending stiffness of a beam can analytically be derived from the equation of beam deflection when it is applied by a force.

where ${\displaystyle \mathrm {p} }$ is the applied force and ${\displaystyle \mathrm {w} }$ is the deflection. According to elementary beam theory, the relationship between the applied bending moment ${\displaystyle M}$ and the resulting curvature ${\displaystyle \kappa }$ of the beam is:

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