Interacting circular inclusions in antiplanepiezoelectricity

The problem of multiple piezoelectric circular inclusions\ which are perfectly bonded to a piezoelectric matrix\ is analyzed in the framework of linear piezoelectricity[ Both the matrix and the inclusions are assumed to possess the symmetry of a hexagonal crystal in the 5 mm class and subject to electromechanical loadings "singularities# which produce in!plane electric _elds and out!of!plane displacement[ Based upon the complex variable theory and the method of successive approximations\ the solution of electric _eld and displacement _eld either in the inclusions or in the matrix is expressed in terms of explicit series form[ Stress and electric _eld concentrations are studied in detail which are dependent on the mismatch in the material constants\ the distance between two circular inclusions\ and the magnitude of electromechanical loadings[ It is shown that\ when the two inclusions approach each other\ the oscillatory behavior of the stress and electric _eld can be induced in the inclusion as the matrix and the inclusions are poled in the opposite directions[ This important phenomenon can be utilized to build a very sensitive sensor in a piezoelectric composite material system[ The present derived solution can also be applied to the inclusion problem with straight boundaries[ The problem associated with three!material media under electromechanical sources is also considered