Elastic potential energy gained by a material under tensile or compressive stress
In physics, the elastic potential energy gained by a wire during elongation with a tensile (stretching) or compressive (contractile) force is called strain energy. For linearly elastic materials, strain energy is:
![{\displaystyle U={\frac {1}{2}}V\sigma \varepsilon ={\frac {1}{2}}VE\varepsilon ^{2}={\frac {1}{2}}{\frac {V}{E}}\sigma ^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3ea678143058307454c6f925f4b42766052ee405)
where σ is stress, ε is strain, V is volume, and E is Young's modulus:
![{\displaystyle E={\frac {\sigma }{\varepsilon }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/6e550b558c0d862ab9e0367371e726a0793aeb44)