Accession Number : ADA310648

Title :   A Closed-Form Dynamic Elasticity Solution to the Fluid/Structure Interaction Problem of a Two-Layer Infinite Viscoelastic Cylinder with Inner and Outer Fluid Loading Subject to Forced Harmonic Excitation.

Descriptive Note : Final rept.,

Corporate Author : NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI

Personal Author(s) : Peloquin, Mark S.

PDF Url : ADA310648

Report Date : 29 DEC 1995

Pagination or Media Count : 264

Abstract : This report documents an exact closed-form solution to the problem of a two-layer viscoelastic solid infinite cylinder that is immersed in an infinite ideal inviscid fluid and contains an infinite ideal inviscid fluid within its diameter. The viscoelasticity is modeled with structural damping, which is incorporated by the use of a complex modulus of elasticity. The composite system is subject to forced harmonic vibration at the outer solid/fluid interface. The response to both nonaxisymmetric (described in terms of circumferential order number n) and axisymmetric excitations is derived. The problem is resolved with a three-dimensional dynamic elasticity solution. Simulations of the transfer surfaces for the interior pressure field are performed for radial excitation P0 and longitudinal excitation Px applied to a single-layer cylinder for n = 0, 1, and 2. The circumferential excitation P theta is applied to the single-layer cylinder for interior pressure simulation with n = 1 and 2. Simulations of the circumferential strain are performed for excitations P0 and Px applied to a two-layer cylinder for n = 0. Additionally, the P0 excitation is applied to the two-layer cylinder for n = 0, 1, and 2, resulting in simulations for the pressure field in the inner fluid. Simulations are displayed as response transfer surfaces in the longitudinal wavenumber-frequency plane. Comparisons are made between the elasticity models derived in this report and the membrane and bending shell models from previous work. The nulls occurring in the interior pressure field at higher frequencies are explored as well as the resonances relating to the thickness of the cylinder.

Descriptors :   *VISCOELASTICITY, *INVISCID FLOW, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, COMPUTERIZED SIMULATION, LOAD DISTRIBUTION, VIBRATION, EQUATIONS OF MOTION, EXCITATION, STRUCTURAL ANALYSIS, DYNAMIC RESPONSE, DISPLACEMENT, MODULUS OF ELASTICITY, DAMPING, COMPUTATIONAL FLUID DYNAMICS, SHELLS(STRUCTURAL FORMS), FLOW FIELDS, SOLUTIONS(GENERAL), WAVE PROPAGATION, CYLINDRICAL BODIES, STRUCTURAL RESPONSE, SHEAR STRESSES, DYNAMIC PROGRAMMING, PRESSURE DISTRIBUTION, TWO PHASE FLOW, GAS SURFACE INTERACTIONS, STRESS WAVES, RADIAL STRESS, BESSEL FUNCTIONS, INTERNAL PRESSURE, AXISYMMETRIC FLOW.

Subject Categories : Fluid Mechanics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE