Theory of frequency response of magnetoelectric effects in radially polarized thin cylindrical composites

A theoretical model for the frequency response of magnetoelectric (ME) effect in thin cylindrical piezoelectric-magnetostrictive composites is presented by using constitutive and elastodynamic equations. The calculated results show that there is a resonant enhancement peak of ME voltage coefficient in the electromechanical resonance region and the ME voltage coefficient at resonance frequency exceeds that at low frequency by one or two orders of magnitude. The resonance frequency is predicted to increase with decreasing average diameter (D) over bar and increasing thickness of magnetostrictive layer t(M) of the cylindrical composite, which is in good agreement with the experimental results reported in literatures. The corresponding resonance ME voltage coefficient increases with increasing t(M), but reaches to a peak value and then decreases with increasing (D) over bar. It is indicated that the ME effect of trilayered cylindrical composite is less than that of bilayered one, possibly due to its symmetric structure. Under clamped condition, the resonance frequency will shift to a very high value for both trilayered and bilayered cylindrical composites, while the ME effect has different performance, enhanced in bilayered but suppressed in trilayered cylindrical composite. Our model shows that one can obtain strong ME effect and proper resonance frequency by selecting suitable materials, optimizing its geometry structure and varying mechanical boundary conditions for the cylindrical composite structure.