DIFFUSION-INDUCED STRESSES IN 2-PHASE ELASTIC MEDIA

The diffusion-induced stresses in two-phase elastic media have been investigated. Two parallel slabs and concentric spheres consisting of two media subject to constant surface concentration and fixed amount of solutes were considered. We used the Laplace transformation method to solve the diffusion equation. We also derived the stress and the strain energy density formulae for the two-phase elastic slabs and spheres. It was found that initially the largest stress is compressive and infinite at the surface for the fixed amount and finite for the constant surface concentration. So it is possible to have plastic failure on the surface, where the largest distortional strain energy density occurs. For the case of thin slab of fixed amount, the largest value of the tensile dilatational strain energy density for the medium of higher value of E V ̄/(1-v) occurs near the free surface and that for the medium of lower one does near the interface. For the case of thin slab of constant surface concentration, the largest value of the tensile dilatational strain energy density is located near the interface. It is also found that the largest value of the tensile dilatational strain energy density is either at the center of sphere in medium one or at the interface in medium two depending on their mechanical properties. These points are likely to be the failure origins. © 1990.