# Beam Deflection

### From DT Online

The deflection of a beam under load may be measured using a dial gauge for example but may also be calculated.

The equation opposite gives **Deflection (Δ)** of a simply supported beam loaded in the centre.

**Where**:

- W = Load
- L = Span
- E =
**Young's Modulus***( - a measure of how stiff the materials is)* - I =
**Moment of Inertia***( - a measure of the capacity of a cross section to resist***bending**)