Three-Dimensional Dynamic Elasticity Solution for Wave Propagation in a Two-Layered Infinite Viscoelastic Solid Cylinder With Outer Fluid Loading

摘要

The research presented in this report provides an exact closed form solution tothe problem of a two layered viscoelastic solid infinite cylinder immersed in an infinite ideal inviscid fluid. Damping is incorporated by the use of a complex modulus of elasticity. The composite system is subject to forced harmonic vibration at the solid fluid interface. The response to both axisymmetric and nonaxisymmetric excitations is derived. A three dimensional dynamic elasticity solution is obtained. Nonaxisymmetric excitation is described in terms of circumferential order number n. For circumferential order numbers n = 0 and n = 1, simulations are performed for excitations P0 and Px applied to the single layer and two layer cylinders. For excitation P9, simulations are performed at n = 1 applied to the two layer cylinder. Simulations are displayed as response transfer surfaces in the longitudinal wavenumber Material properties consistent with those of an optical fiber and ALORYN were chosen for the simulations. The strain and optical phase sensitivity of the optical fiber to longitudinal shear stress is 30 to 110 dB greater than the optical fiber sensitivity to radial pressure excitation. In the ALORYN coated case, a comparison between the optical phase sensitivity to radial pressure and longitudinal shear stress reveals a shear stress response that is 50 to 70 dB greater than the radial pressure response. This result is consistent with that for the bare optical fiber.