Explanation: Bending equation states that: $\frac{\sigma }{y} = \frac{M}{I} = \frac{E}{R}$ Various terms in above bending equation are: σ = Bending stress y = Distance from neutral axis M = Bending moment I = Area moment of inertia E = Modulus of elasticity R = Radius of curvature Bending Stress distribution for I section: Bending stress is directly proportional to y (Distance from the neutral axis). Bending stress will be zero at neutral axis. The maximum stress always occurs at the outermost fibre.