An effective medium approximation of nonlinear composites with spherical particle

We have proposed a nonlinear effective medium approximation (EMA) method to estimate the bulk effective conductivities of weakly nonlinear composite m edia, which obey a current-field relation of the form J = sigmaE + x \E\(2) E. As an example in three dimensions, we apply the EMA method to deal with a spherical inclusion in a host and derive the approximate analytic formul ae of nonlinear effective response, which are suitable for the larger volum e fraction of spherical inclusion. From our results, we can exactly obtain the generalized Landau formulae in the dilute limit.