On the effects of microstress on macroscopic diffusion processes (Q1301910)

The authors study the problem of diffusion in materials with spatialIy variable stress-dependent diffusivity. Several examples are stated to illustrate the predicted discrepancies between the behaviour corresponding to the solutions under the stress-dependent and stress-free conditions. Variational formulations are presented to treat the problem in both unstressed and stressed cases, and then the reuslts are applied to provide a general upper bound in the stress-dependent behaviour. The results are compared with the classical bounds by Hill, Reuss and Voigt.