An Integral Equation Approach to the Inclusion Problem of Elastoplasticity

An integral equation approach is derived for the calculation of the elastoplastic strain field associated with a transformed inclusion of constant stress-free transformation strain and for an inhomogeneity when the far stress field remains elastic. The assumptions of a coherent precipitate and the deformation theory of plasticity are employed although any yield condition and flow rule can be chosen. The complexity of the integral equation is such that an iterative solution scheme is necessary. The technique is applied to a spherical precipitate in a uniform elastic stress field where associated stress and strain fields and plastic zone are calculated. The nature of the plastic relaxation process compares qualitatively with two-dimensional plane stress behavior. Extension of this technique to the nonaxisymmetric problem is also examined.