A surface chemical potential for elastic solids

The surface chemical potential field represents the tendency for an elastic solid to lower its free energy by means of mass rearrangement. In a recent paper in this Journal, Wu [1996, J. Mech. Phys. Solids 44, 2059-2077] poin ted out that the commonly used definition of chemical potential for elastic solids is inconsistent with the change in free energy of the system associ ated with shape change at finite strain. The purpose here is to rederive Wu 's main result by a direct rate calculation, rather than a variational appr oach, which appears to be simpler in implementation. In addition, the defin ition is generalized to include orientation dependence of surface energy. ( C) 1998 Elsevier Science Ltd. All rights reserved.