# Modulus of elasticity

A material property: the ratio of axial stress to axial strain below the elastic limit. (Also called Young's modulus.)

An isotropic material has only one modulus of elasticity. An orthotropic material like titanium has three principal moduli of elasticity. The modulus of elasticity may also depend on the size of the raw stock.

The modulus of elasticity decreases with temperature.

For an isotropic material, if the thin-wire wave speed is known then the modulus of elasticity can be calculated from —

\begin{align} \label{eq:12301a} E &= \rho \, {c_{tw}}^2 \end{align}

where —

 $$E$$ = modulus of elasticity (Young's modulus) $$\rho$$ = density $$c_{tw}$$ = thin-wire wave speed