Study On Magnetoelectric Effect Of Layered Magnetostrictive/Piezoelectric Composites

In this paper, the magnetoelectric effect of the layered magnetoelectric composite was studied by theoretical modelling, and its main relvant factors were discussed, then a part of theoretical results were verified experimentally.According to the boundary conditions of the layered magnetoelectric composites, the 3-1 direction models of the multilayer(no more than three layeres)symmetric magnetoelectric composites were classified as six cases, including the free state with the interface perfectly bonded together, the free state with the non-ideal interface bonded together, clamped ends with no friction and the interface without bonding, clamped ends with no friction and the interface perfectly bonded together, clamped ends with no friction and the the non-ideal interface bonded together, the rigid clamp, and the magnetoelectric voltage coefficients were derived in connect with the governing equations of the layered magnetoelectric composites themselves.Based on the assumptions of the perfect elastica and without initial stress, the small deformation of two-layered clamped plates induced by the magnetic field was analyzed by energy minmization, and its magnetoelectric effect was discussed under the condition that the length of the plate is very large in contrast with its width and the Possin ratios of themagnetoelectric phases are same and their thicknessses are d_a << d_b.The coefficients for various materils used for calculationsusing the formulae derived above were given, and its main relvant factors were discussed, including the property coefficients of each phase, the thicknesss of each phase and their thicknesss ratios, the interface coupling parameter k and the volume fraction of magnetostrictive phase v, the laminated stuucture, the limmited mechanical condition, the directions of the magnetic field and the electric field, and so on.The samples were prepared and its voltages induced by the outer interchage magnetic field were measured by the designed devices, the analyses of the theoretical values in contrast with the experimental values show that the errors of different kinds of samples are not the same, and the theoretical results derived using mechantical methods accord with the experimental results well for the layered symmetric magnetoelectric composites.