Singularity Analyses of Three-Dimensional Magneto-Electro-Elastic Bodies of Revolution and Wedges
| Autor: | Hu, Cheng-Ning, 胡政甯 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Magneto-electro-elastic (MEE) materials and piezoelectric material are able to exchange mechanical, electric, and magnetic forms of energy among themselves and have been widely used in electronic devices. A comprehensive understanding of the magneto-electro-elastic singularities induced by geometry is valuable in optimizing the design of MEE components and analyzing their failures. The main purpose of this research is to establish three-dimensional asymptotic solutions for magneto-electro-elastic singularities in bodies of revolution and wedges. The solutions are obtained by combining an eigenfunction expansion approach with the power series solution method to solve three-dimensional equilibrium equations and Maxwell’s equations in terms of mechanical displacement components and electric and magnetic potentials. Assume the MEE material is transversely isotropic, its polarization direction is not necessarily parallel to the axis of revolution of a body of revolution or normal to the mid-plane of a wedge. Therefore, the in-plane components of displacement, electric, and magnetic fields are generally coupled with their out-of-plane components, which causes difficulties in finding the solution. The analyses of bodies of revolution and wedges in the published literature are based on generalized plane strain assumption. However, the proposed method makes no simplification or assumption to construct the asymptotic solutions at vertex of bodies of revolution and wedges. The developed solutions are further employed to examine the effects of the direction of polarization, the configuration, the material components and boundary conditions on the orders of the MEE singularities in bodies of revolution and wedges that comprise a single MEE material (BaTiO3-CoFe2O4) or a single piezoelectric material (PZT-4 and PZT-6B) and bonded MEE/isotropic elastic (BaTiO3-CoFe2O4/Si), MEE/piezoelectric (BaTiO3-CoFe2O4/PZT-4 or BaTiO3-CoFe2O4/PZT-6B), MEE/MEE(BaTiO3-CoFe2O4(V(1)I = 50%)/BaTiO3-CoFe2O4(V(2)I = 20%)), piezoelectric/isotropic elastic (PZT-4/Si 或PZT-6B/Si), or piezoelectric/piezoelectric (PZT-4/PZT-6B) materials. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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