The effect of interfaces on the plastic behavior of periodic composites

M. I. IDIART; N. A. FLECK

Philosophical Magazine

Taylor & Francis

Año: 2008 vol. 88 p. 3633 - 3653

1478-6435

A theoretical framework is given for predicting the effect of microstructural size on the strength of $N$-phase periodic composites. It is assumed that the strength is elevated by plastic strain gradients in the bulk and by the resistance to plastic slip at internal material interfaces. Calculations are given for a two-phase, power-law material with a cubic array of spherical reinforcement particles. The macroscopic stress-strain relations are found to exhibit Hall-Petch behavior, and the size effect becomes more pronounced with increasing interface strength. Moreover, size effects are predicted for both yield strength and plastic hardening rate of the composite. The relative magnitude of these two effects is sensitive to the choice of constitutive description of the interface.