Effect of interfacial stresses on the elastic behavior of nanocomposite materials

This work analyzes the effective bulk modulus of a composite material consisting of spherical inclusions at dilute concentrations. By introducing the theory of surface elasticity and accounting for the contribution of interfacial stresses, a closed-form expression for the effective bulk modulus is derived. The analysis shows that the dependence of the elastic response on the size of the embedded inclusions in the composite material is different from the classic results obtained in the theory of linear elasticity. This is because of shrinkage of the inclusions caused by the interfacial stresses. The interfacial stresses can either enhance or reduce the effective bulk modulus depending on the bulk modulus ratio of matrix to inclusion.