Torsional Vibrations of Coated Hollow Poroelastic Spheres

作     者：Syed Ahmed Shah Chinta Nageswaranath Modem Ramesh Mangipudi Venkata Ramanamurthy 

作者机构：Department of Mathematics Deccan College of Engineering and Technology Hyderabad India Department of Mathematics Vardhaman College of Engineering Hyderabad India Department of Mathematics College of Technology Osmania University Hyderabad India Department of Mathematics Osmania University Hyderabad India 

出 版 物：《Open Journal of Acoustics》 (声学期刊（英文）)

年 卷 期：2017年第7卷第1期

页      面：18-26页

学科分类：08[工学] 0801[工学-力学（可授工学、理学学位）] 

主　　题：Coated poroelastic Sphere Torsional Vibrations Permeable Surface Impermeable Surface Frequency Equation Dissipation Mode of Vibration 

摘      要：Torsional vibrations of coated hollow poroelastic spheres are studied employing Biot’s theory of wave propagation in poroelastic solid. The dilatations of solid and liquid media are zero, therefore the frequency equation of torsional vibrations is same both for a permeable and an impermeable surface. The coated poroelastic sphere consists of an inner hollow poroelastic sphere bounded by and bonded to a sphere made of distinct poroelastic material. The inner sphere is designated as core and outer sphere as casing. Core and casing are bonded at the curved surfaces. The inner and outer boundaries of the coated hollow poroelastic sphere are free from stress and at the interface of core and casing the displacement and stresses are continuous. It is assumed that the each material of coated sphere is homogeneous and isotropic. The frequency equation of torsional vibrations of a coated poroelastic hollow sphere is obtained when the material of the core vanishes. Also a coated poroelastic solid sphere is obtained as the limiting case of the frequency equation of coated hollow poroelastic sphere when the inner radius of core approaches to zero. Non-dimensional frequency as a function of ratio of thickness of core to that of inner radius of core is determined and analyzed. It is observed that the frequency and dispersion increase with the increase of the thickness of the coating.