An effective nonlinear response of a nonlinear composite with spherical coated inclusions randomly embedded in a host medium under the action of an external AC electric field,E a=E 1 sin(ωt) + E 3 sin(3ωt),is investigated using a perturbation method.The local potentials of the composite at higher harmonics are given both in the region of local inclusion particles and in the local host region under the external AC electric field.All effective nonlinear responses of the composite and the relationship between the effective nonlinear responses at the fundamental frequency and third harmonics are also studied for spherical coated inclusion in a dilute limit.
