Study On The Magnetoelectric Response Of Magnetostrictive/Elastic/Piezoelectric Laminate Composite

The megnetoelectric (ME) effect of giant magnetostrictive material (GMM, Tb1-x DyxFe2-y) and piezoelectric material (Pb(Zr1-xTix)O3, PZT-5H) bonded on an elastic substrate is reported. When GMM vibrates at frequencies near the natural frequencies of the substrate, producing stress or strain, which is transferred by adhesive layer to drive the elastic substrate vibrating in resonance, then the output voltage of PZT reaches to maximum. As such, the ME effect provides a transduction method between magnetic and electric field signals. Important applications of this structure are magnetic field sensors and magnetoelectric transducers, with the main advantage being that they require no external power to operate.Firstly, Hamilton principle is used to derive motion equation of GMM/elastic substrate/PZT laminated structure, then combined with magnetostrictive equation and piezoelectric equation to derive magnetoelectric response of the structure, obtaining numerical calculation figure of ME voltage coefficient vs. frequencies. During the derivation, the strain model of adhesive layer is built to consider the effect of adhesive layer, including longitudinal strain and shear strain. The property parameters and geometry parameters of adhesive layer are brought into the calculation of ME response. The main factors of ME response are discussed. The maximum ME voltage coefficient is obtained under resonant frequencies, which is one or two order of magnitude higher than that of non-resonant frequencies, so is the average strain of the structure.To verify the theoretical results, a ME response measure system is built up. The making procedure of the structure and the cautions to the test system are introduced respectively, and the principle of experimental testing is explained. ME response is measured by the active method. Numerical calculation and experimental results are compared and discussed. The ME response of the structure with different lengths of elastic substrate is analyzed under the first longitudinal resonant frequency. It shows that elastic substrate can adjust the resonant frequency, and ME voltage coefficient of the structure with 60mm-length elastic substrate is twice higher than that of GMM/PZT laminated composite.