Magnetoelectricity in piezoelectric-piezomagnetic fibrous composites with imperfect interface
Hsin-Yi Kuo (National Chiao Tung University)
Mechanics of Phase Transforming and Multifunctional Materials
Wed 10:45 - 12:15
CIT 219
Magnetoelectricity (ME) in multiferroic compostes, which is related to inducing an electric polarization by a magnetic field or conversely inducing a magnetization by an electric field, is the topic of a number of theoretical and experimental investigations. The ME effect in the multiferroic composite is achieved through the product property: an applied magnetic field generates a strain in the ferromagnetic material which in turn induces a strain in the ferroelectric material, resulting in a polarization. Each phase possesses either magnetostrictive or piezoelectric properties, and the product ME effect is a new property determined by the mechanical interaction between the two phases. Therefore, the interface is critical in achieving the giant magnetoelectricity. The objective of this work is to propose a theoretical framework for evaluation of the effective behavior of piezoelectric and piezomagnetic circular fibrous composites with imperfect interface. We generalize the classic work of Rayleigh in a periodic conductive perfect composite to the current coupled magnetoelectroelastic imperfect composites. Two kinds of imperfect contact are studied: mechanically stiff and dielectrically/magnetically highly conducting interfaces, and mechanically compliant and dielectrically/magnetically weakly conducting interfaces. For the former case, the potential field is continuous across the interface, while the normal component of the flux undergoes a discontinuity which is proportional to the local surface Laplacian of the potential field. For the latter one, the normal component of the flux is continuous, while there is a jump of potential field across the interface. We use this method to study BaTiO3-CoFe2O4 composites and provide a deeper insight into the influence of the imperfect contact.