Influence of stress interaction effects upon pore motion in solids

Abstract

A computer oriented analysis was undertaken in an attempt to fix the sign and magnitude of the response of a pore to a stress field. The present work agrees very well with an analytical result of other authors for the interaction of two bubbles within a solid continuum and reasonably well with their approximate analytical result for the interaction between a bubble and a free surface. The interaction between a bubble and a clamped surface is obtained. Two bubbles will always attract as long as at least one contains some “uncompensated” pressure. Further, such a bubble will be attracted to a free surface and repelled from a clamped surface. An analytical solution to the problem of an equilibrium bubble placed in a linear uniaxial stress gradient indicates the bubble will move up the gradient, whether the gradient is produced by external tension or compression. This is compared with a previous result for a pressure gradient; the uniaxial stress gradient produces a force about 50% higher than that due to a pressure gradient. Finally, estimates are made for the magnitude of these forces under physically plausible conditions.