Interface energy effect on effective elastoplastic behavior of spheroidal particle reinforced metal matrix nanocomposites.

• The interface energy effect is considered to predict the elastoplastic properties of nanocomposites. • Randomly located and randomly oriented spheroidal particles in the nanocomposites are investigated. • The orientational averaging procedures are applied to evaluate the effect of the particle orientations. • The interface elasticity and interface residual stress are studied simultaneously in considering the interface energy effect. • Effective secant moduli are demonstrated to be dependent on the particle size and the interface residual stress. A nanomechanical framework is proposed to predict the effective elastoplastic behavior of the metal matrix nanocomposites (MMNCs) containing randomly distributed and randomly oriented spheroidal particles. The interface energy effect is investigated by considering both of the interface elastic stress and the interface residual stress on the idealized zero-thickness membrane interphase between the matrix and the inhomogeneities. The orientational average is performed to obtain the effective constitutive relations of the MMNCs with randomly oriented spheroidal particles. By employing the micromechanical homogenization approaches, an effective yield criterion is formulated, and the effective secant moduli of the MMNCs are derived. Comparisons are made between the present framework and the classical micromechanics theory. The interface energy effect on the effective secant moduli are discussed, and the particle size dependence of the effective secant moduli is revealed. Furthermore, the effects of the interface elastic stress and the interface residual stress on the plastic yielding of the nanocomposites are discussed. Lastly, the theoretical predictions obtained by the present framework are compared with the relevant experiments and numerical simulations. [ABSTRACT FROM AUTHOR]