The paper deals with a body having a random 3D-distribution of two-phase inclusions: spheroidal mutually parallel voids as well as differently oriented reinforcing parallel stiff spheroidal short fibers. By the effective field approach the effective stiffness fourth-order tensor is formulated and found numerically. Simultaneous and sequential embeddings of inclusions are compared. Damage evolution is described by modified Vakulenko's approach to endochronic thermodynamics. A brief account of the problem of effective elastic symmetry is given. The results of the theory are applied to the damage-elasto-viscoplastic strain of reactor stainless steel AISI 316H.