NONLINEAR SUSCEPTIBILITY OF STRONGLY NONLINEAR COMPOSITES

By means of a variational approach, we study the effective response of strongly nonlinear composite media with a low concentration of cylind rical or coated cylindrical inclusions. In an attempt to consider the influence of nonlinear order to effective nonlinear response, we assum e that every constituent of the composites obeys a current-field. rela tion of the form J = chi\E\E-beta. In dilute limit, we have presented some numerical results for the case of the third-order nonlinearity (i .e. beta = 2) and the fifth-order nonlinearity (i.e. beta = 4), and co mpared the effective response of the third-order nonlinearity with tha t of the fifth-order nonlinearity, some conclusions are drawn.