Acoustic radiation from a submerged hollow FGM sphere |
| |
Authors: | Seyyed M Hasheminejad Sadeq Malakooti Hessam Mousavi Akbarzadeh |
| |
Institution: | (1) Design and Production Engineering Department, Ain Shams University, Cairo, Egypt;(2) Professor and Director of Small Smart Systems Center and Director of Smart Materials and Structures Research Center, Mechanical Engineering Department, University of Maryland, 2137 Engineering Bldg, College Park, MD 20742, USA; |
| |
Abstract: | An exact study based on the linear theory of elasticity is presented for the steady-state sound radiation characteristics
of an arbitrarily thick radially inhomogeneous elastic isotropic hollow sphere, immersed in and filled with ideal compressible
fluids, and subjected to an arbitrary axisymmetric time-harmonic driving force at its internal surface. A modal state equation
with variable coefficients is set up in terms of appropriate displacement and stress functions and their spherical harmonics
by means of the laminated approximation approach. Taylor’s expansion theorem is subsequently employed to solve the modal state
equation, ultimately calculating a global transfer matrix. Numerical results are presented for a water-submerged/air-filled
steel/zirconia FGM hollow sphere under an axisymmetric distributed internal pressure force. The effects of shell wall thickness,
the material compositional gradient, frequency, and subtended polar angle of the internal pressure force on the far-field
radiated pressure directivity patterns as well as the total radiated power are examined. It is demonstrated that the material
gradient can significantly change the acoustical characteristics of hollow inhomogeneous sphere, especially for thick shells
at high excitation frequencies. Limiting cases are considered and good agreements with available results as well as with the
computations made by using a finite element package are obtained. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|