The problem of wave propagation in an infinite, fluid-loaded, homogeneous, transversely isotropic cylinder is studied within the framework of the linearized, three-dimensional theory of elasticity. The equations of motion of the cylinder are formulated using the constitutive equations of a transversely isotropic material with a preferred material direction collinear with the longitudinal axis of the cylinder. The equations of motion of the internal and external fluids are formulated using the constitutive equations of an inviscid fluid. Displacement potentials are used to solve the equations of motion of the cylinder and the fluids. The frequency equation of the coupled system, consisting of the cylinder and the internal and external fluids, is developed under the assumption of perfect-slip boundary conditions at the fluid–solid interfaces. This frequency equation is general in axial wave number k, circumferential wave number n, cylinder wall thickness h, and radial frequency ω. Simplifications to the frequency equation for the cases of zero wave number and material isotropy are discussed.
The frequency equation of a coupled system consisting of an infinitely long, fluid-loaded, homogeneous, transversely isotropic cylinder was derived in Part I ͓J. Acoust. Soc. Am. 99, 1841-1847 ͑1996͔͒. In this paper, Part II, the frequency spectra for the nϭ1 nonaxisymmetric modes of wave propagation are presented for hollow cylinders, fluid-filled cylinders, and cylinders that are fluid filled and immersed in fluid. These frequency spectra consist of the first three branches corresponding to the flexural mode, the longitudinal mode, and the circumferential mode. Since propagation modes are of primary interest, branches extending into the imaginary and complex wave-number domain are not included in this study. Numerical results for an isotropic ͑linearly elastic͒ rubber cylinder are compared to the results for a highly anisotropic, fiber-reinforced cylinder. The material properties of the rubber cylinder are identical to the properties of the matrix material of the fiber-reinforced cylinder. It is shown that the characteristics of wave propagation in the fiber-reinforced cylinder, with and without fluid loading, are markedly different from the characteristics of wave propagation in the isotropic cylinder.
An overview of fiber-optic sensor designs and performance for underwater sonar applications will be discussed. The sensor designs range from simple, coated fibers to mandrels wrapped with single or multiple layers of fiber. The measurable response of fiber-optic sensors is through changes in the phase of light in the fiber due to the internal components of strain. The assumed strain in models of the acoustic response of optical fiber sensors differs for the various sensor designs and often are derived from an analysis of deformations of a complex, composite structure. Another consideration in the design of fiber-optic sensors is structural resonances, which may interfere with acoustic performance. Comparisons of modeled and measured acoustic and static pressure sensitivities of various fiber-optic sensor designs will be presented along with laboratory measurements of vibration response.
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