Abstract
We study the effective properties of a linear elastic or perfectly viscoplastic composite consisting of a soft matrix reinforced by possibly very stiff fibers.The effective material is characterized by the emergence of a discrepancy between the displacement in the fibers and the overall averaged displacement,giving rise to a concentration strain in the matrix. This phenomenon is attended by the appearance a combination of stretching, bending and torsional energies stored in the fibers.This work completes and corrects results previously obtained by the author et al., who failed to notice the torsional contribution.