Dissemination of IT for the Promotion of Materials Science (DoITPoMS)

# Extension ratio

The extension ratio, λ , is a measure of how much an object has been extended. For an object with initial length l0 and extended length l,

$$\lambda = {l \over {{l_0}}}$$

and so λ = 1 + strain

The extension ratio is commonly used when discussing the mechanical properties of rubber, with tensile strain being used in other applications. In this TLP, both extension ratio and strain are used.