CONSTITUTIVE DESCRIPTION OF CREEP IN POLYGONIZED SUBSTRUCTURES

Constitutive equations of creep in polygonized substructures are formu lated based on the composite model of heterogeneous dislocation struct ure. The suggested set of equations consists of a kinetic equation, wh ich takes into account the elastic and plastic components of strain in hard and soft regions of the structure, and of two evolution equation s, which describe the evolution of the local stress in soft regions an d of the volume fraction of hard regions chosen as internal variables. As an illustration, the equations are applied to creep and dislocatio n structure data of alpha-iron discussed recently from another point o f view.