Investigation On Waves Propagation And Dispersion Relation In Layered Magnetoelectroelastic Materials

Magnetoelectroelastic materials made of piezoelectric/piezomagnetic materials can exhibit a significant magnetoelectric effect. In recently years, magnetoelectroelastic materials are extensively applied in many fields, such as acoustic wave devices, filter, transducer, electromagnetic surveying and so on. So the study of wave propagation behaviors and dispersion characteristics in magnetoelectroelastic materials has become a topic of practical importance.The research results of wave propagation behaviors and dispersion characteristics in piezoelectric materials are very abundant at present. This thesis mainly considers the mathematical models of several kinds of waves(surface wave, interfacial wave and air gap wave) propagation in layered magnetoelectroelastic materials, and analyzes the corresponding dispersion relation. It includes the following parts:(1) Find the solution of the magnetoelectroelastic coupling factors in infinite magnetoelectroelastic material half-space. Give the expression of the surface wave velocity. Extend this result to functionally graded magneto- electroelastic materials.(2) Investigate interfacial waves near an imperfectly bonded interface in piezoelectric-piezomagnetic material half-spaces and two magnetoelectro- elastic material half-spaces. Analyze the dispersion characteristics of the corresponding interfacial waves.(3) Establish the dispersion relation models of symmetric and anti- symmetric waves in an infinite magnetoelectroelastic material plate, air gap waves in two identical magnetoelectroelastic material half-spaces with air gap and interfacial waves in two identical magnetoelectroelastic material half- spaces with a plate.(4) Give the corresponding degradation models if the magnetoelectro- elastic materials reduce to piezoelectric materials.According to the results in this thesis waves propagation in magneto- electroelastic materials are subjected to the influence of electric-magneto- mechanical coupling effect. The velocity of the waves is related to piezoelectric, piezomagnetic, electromagnetic, elastic constants, dielectric permitivity, magnetic permeability, density and wave number. These results are different from the piezoelectric materials. For dissimilar layered structure, the velocity is related to the cementing effect and the characteristic dimension. The results in this thesis provide the theoretical models for the study of the numerical analysis on surface and interfacial waves.