caa a22 4500 445811811 CHVBK 20180317145214.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00419-011-0525-0 doi (NATIONALLICENCE)springer-10.1007/s00419-011-0525-0 Acoustic radiation from a submerged hollow FGM sphere [Elektronische Daten] [Seyyed Hasheminejad, Sadeq Malakooti, Hessam Akbarzadeh] 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. Springer-Verlag, 2011 Sound radiation nationallicence Functionally graded shell nationallicence State-space method nationallicence Radiated power nationallicence Hasheminejad Seyyed Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut Malakooti Sadeq Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut Akbarzadeh Hessam Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut Archive of Applied Mechanics Springer-Verlag 81/12(2011-12-01), 1889-1902 0939-1533 81:12<1889 2011 81 419 https://doi.org/10.1007/s00419-011-0525-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00419-011-0525-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hasheminejad Seyyed Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut NATIONALLICENCE 700 1- Malakooti Sadeq Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut NATIONALLICENCE 700 1- Akbarzadeh Hessam Acoustics Research Lab., School of Mechanical Engineering, Iran University of Science and Technology, Narmak, 16844, Tehran, Iran aut NATIONALLICENCE 773 0- Archive of Applied Mechanics Springer-Verlag 81/12(2011-12-01), 1889-1902 0939-1533 81:12<1889 2011 81 419 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer