Strain energy

In physics, strain energy is the energy stored by a system undergoing deformation. For elastic materials, strain energy is:
${\displaystyle U={\frac {1}{2}}V\sigma \epsilon ={\frac {1}{2}}VE\epsilon ^{2}={\frac {1}{2}}{\frac {V}{E}}\sigma ^{2}}$
where σ is stress, ε is strain, V is volume, and E is Young's modulus:
${\displaystyle E={\frac {\sigma }{\epsilon }}}$

In a molecule, strain energy is released when the constituent atoms are allowed to rearrange themselves in a chemical reaction. The external work done on an elastic member in causing it to distort from its unstressed state is transformed into strain energy which is a form of potential energy. The strain energy in the form of elastic deformation is mostly recoverable in the form of mechanical work.

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