Dissipative flow model based on dissipative surface and irreversible thermodynamics

A dissipative flow model is presented to describe dissipative deformation p rocesses in a macroscopic solid continuum. Dissipative process may consist of material plasticity, material damage and other intrinsic mechanical phen omena represented by internal variables. The concept of a dissipative surfa ce is introduced in the paper to distinguish between conservative and dissi pative processes. Conventional plastic yielding and damage initiation are e xpressed by a unique condition which may else include other possible intrin sic mechanical dissipations. The proposed model is based on the principles of irreversible thermodynamics and the minimum free energy theorem. A modif ied material stability postulate, modified Drucker's postulate, in thermody namic stress space is also used to obtain the same results.