Calcolatrice Rapporto di Poisson — Formula
## Poisson's Ratio
When a material is stretched, it contracts laterally. Poisson's ratio quantifies this coupling.
### Formula
**nu = -epsilon_lateral / epsilon_axial**
Since lateral strain is opposite in sign to axial strain, nu is positive. Most metals have nu between 0.25 and 0.35. Steel is approximately 0.30, aluminium 0.33, rubber approaches 0.50 (incompressible). Cork is near zero.
When a material is stretched, it contracts laterally. Poisson's ratio quantifies this coupling.
### Formula
**nu = -epsilon_lateral / epsilon_axial**
Since lateral strain is opposite in sign to axial strain, nu is positive. Most metals have nu between 0.25 and 0.35. Steel is approximately 0.30, aluminium 0.33, rubber approaches 0.50 (incompressible). Cork is near zero.
Esempio Risolto
A steel rod under tension shows 0.001 axial strain and 0.0003 lateral contraction.
- nu = 0.0003 / 0.001 = 0.300
- This is a typical value for structural steel.