Thermodynamics of hyperelastic solid

[hoomanya]

Can someone please help with hyperelastic theory, I need to know how changes in reversible work are related to energy density function and then to strain and stress tensors. A reference that explains the theories simply would also be appreciated. So far I have failed to find anything relatively simple. Please help (urgent)

 

[Chestermiller]

https://en.wikipedia.org/wiki/Hyperelastic_material