Gradient theories of ductile and brittle damage: a thermodynamical consistent framework and computational issues

摘要

In this paper a thermodynamically consistent framework for gradient theories of ductile and brittle damage is presented. It is assumed that evolving microdefects have inertia and that their motion is caused by microforces, which have to satisfy their own dynamical balance laws. Besides the balance laws of macro- and microforces we formulate the first and second law of thermodynamics for macro- and mesolevel. Assuming the constitutive equations in general form, it is shown that macro- and microforces consist of two parts, a non-dissipative part, which can be derived from a free energy potential, and a dissipative part, which can be considered as dissipative driving force. Finally, some computational issues are briefly discussed.