Free Poisson's Ratio Calculator

Determine Poisson's ratio from measured lateral and axial strains during a uniaxial test.

mm/mm
mm/mm

Poisson's Ratio (nu)

0.300

Poisson's Ratio (nu) vs Lateral Strain (transverse)

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.

Example Calculation

A steel rod under tension shows 0.001 axial strain and 0.0003 lateral contraction.

  1. 01nu = 0.0003 / 0.001 = 0.300
  2. 02This is a typical value for structural steel.

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