Variational-Lagrangian irreversible thermodynamics of initially-stressed solids with thermomolecular diffusion and chemical reactions

A GENERAL principle of virtual dissipation in irreversible thermodynamics is applied to a solid under initial stress with small non-isothermal incremental deformations and coupled thermomolecular diffusion and chemical reactions. Dynamical field and Lagrangian equations are obtained directly by variational procedures. In addition, the treatment embodies new fundamental concepts and methods in the thermodynamics of open systems and thermochemistry. The new concept of 'thermobaric potential' is briefly outlined. The theory is also applicable to porous solids with 'diffusionlike' behaviour of pore-fluid mixtures. General validity of viscoelastic correspondence for chemical or other relaxation processes with internal coordinates is indicated in acoustic propagation and seismic problems.