Euler–Bernoulli beam theory
Euler–Bernoulli beam theory (also known as engineer's beam theory or classical beam theory) is a simplification of the linear theory of elasticity which provides a means of calculating the load-carrying capacity and deflection of beams. When external forces are applied to a beam, internal shear forces and bending moments develop causing bending and curvature.
Source: Wikipedia — Euler–Bernoulli beam theory (CC BY-SA 4.0)