Three-dimensional finite element simulation of magnetic-mechanical-electrical coupling in layered cylindrical multiferroic structures

The excellent magnetoelectric (ME) performance of multiferroic structures under room temperature has inspired a wide range of applications in smart devices like energy collectors, ME transducers, neo-antennas, etc. Starting from the constitutive equations of ferroelectric and ferromagnetic materials, a three-dimensional (3D) finite element simulation model was set up to investigate the ME behaviors of the cylindrical structures consisting of Terfenol-D and lead zirconate titanate (PZT). Then the solid mechanical module, electrostatic module and the magnetic module are coupled to calculate the mechanical, electrical and magnetic properties of the components and the structures. The calculated ME coefficients were in good agreement with the experimental data. The results show that P/T and T/P structures reach the maximum of ME coefficients at different bias magnetic fields, approximately 2.5 x 104 A/m for P/T structure and 4.8 x 104 A/m for T/P structure. The maximum value of alpha E31 in the P/T structure is twice that of T/P structure. Moreover, the distribution of magnetic, mechanical, and electrical fields of the composites are also analyzed. The results show that the magnetization of the ferromagnetic material exhibits a non-uniform distribution at low magnetic field, the stress concentration occurs at the Terfenol-D and PZT interface, and the electric potential of piezoelectric material is non-uniform in the plane. Finally, the influence of the interface characteristics on the ME effect is also studied. It is found that, the thicker the interface and the lower the Young's modulus, then the smaller the corresponding ME coefficient for the P/T structure.