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Journal ArticleDOI

Dynamic behavior and sound transmission analysis of a fluid–structure coupled system using the direct-BEM/FEM

23 Jan 2007-Journal of Sound and Vibration (Academic Press)-Vol. 299, Iss: 3, pp 645-655
TL;DR: In this paper, a direct-BEM/FEM method was proposed to analyze the vibration and acoustic radiation characteristics of a submerged structure, which is more effective than FEM in computing the underwater sound radiation of the stern structure.
About: This article is published in Journal of Sound and Vibration.The article was published on 2007-01-23. It has received 52 citations till now. The article focuses on the topics: Sound transmission class & Finite element method.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors presented numerical studies on the vibration and acoustic response characteristics of a fiber-reinforced composite plate in a thermal environment by considering the inherent material damping property of the composite material.

129 citations


Cites background from "Dynamic behavior and sound transmis..."

  • ...[12] for detailed information on the formulation of direct BEM/FEM....

    [...]

Journal ArticleDOI
TL;DR: In this article, the authors presented numerical simulation studies on the vibration and acoustic response characteristics of an isotropic rectangular plate in a thermal environment using commercial finite element softwares ANSYS and SYSNOISE.
Abstract: This paper presents numerical simulation studies on the vibration and acoustic response characteristics of an isotropic rectangular plate in a thermal environment using commercial finite element softwares ANSYS and SYSNOISE. First the critical buckling temperature is obtained, followed by modal and harmonic analyses considering prestress due to the thermal field in the plate, with the critical buckling temperature as a parameter. The vibration response predicted is then used to compute the sound radiation. It is found that the displacement response of the structure increases with an increase in temperature for all boundary conditions. The overall sound radiation of the plate marginally increases with an increase in temperature for all boundary conditions when the temperature approaches the critical buckling temperature although there is a sharp increase in sound power levels.

87 citations

Journal ArticleDOI
TL;DR: In this article, the natural frequency of fluid-structure interaction in pipeline conveying fluid is investigated by eliminated element-Galerkin method, and the expressions of first natural frequency are simplified in the case of different boundary conditions.

74 citations

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional sono-elastic method in the frequency domain is proposed to conduct the comprehensive analysis of fluid-structure interactions, acoustic radiation and acoustic propagation.

38 citations

Journal ArticleDOI
TL;DR: A numerical model to predict the vibro-acoustic behavior of an externally fluid loaded shell with non-uniformly space stiffeners and transversal bulkheads is described, an extension of the existing semi-analytic capability in predicting the acoustics of axisymmetric structures.
Abstract: This paper describes the development of a numerical model to predict the vibro-acoustic behavior of an externally fluid loaded shell with non-uniformly space stiffeners and transversal bulkheads. This model constitutes an extension of the existing semi-analytic capability in predicting the acoustics of axisymmetric structures. It is based on the circumferential admittance approach (CAA) which consists in substructuring the problem so that the fluid loaded shell constitutes one subsystem and the frames constitute other independent subsystems. These subsystems are coupled together by assembling the circumferential admittances that characterize each uncoupled subsystem. Different numerical approaches can be used to estimate these admittances. The standard finite element code is well adapted for evaluating the admittances of the internal frames whatever their cross-section geometries and material properties. Classical discretization methods such as finite elements and boundary elements are too time-consuming for the fluid loaded shell. To avoid this obstacle, three different approaches with different degrees of approximation are proposed to estimate the shell admittances. Comparisons with a reference case are proposed to evaluate the accuracy and the efficiency of each of these three approaches. With the optimal approach, CAA gives very good results in satisfactory computing time. It is well-adapted for analyzing the behavior of a submarine pressure hull in a wide frequency range of interest.

35 citations


Cites background from "Dynamic behavior and sound transmis..."

  • ...This increases dramatically as the frequency increases (see [2-5])....

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References
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Book
01 Jan 1979

2,002 citations

Book
28 Feb 1984
TL;DR: In this article, the authors propose a method of approximate boundary refinement based on the theory of elasticity, and apply it to two-dimensional problems with different types of boundary conditions.
Abstract: 1 Approximate Methods.- 1.1. Introduction.- 1.2. Basic Definitions.- 1.3. Approximate Solutions.- 1.4. Method of Weighted Residuals.- 1.4.1. The Collocation Method.- 1.4.2. Method of Collocation by Subregions.- 1.5. Method of Galerkin.- 1.6. Weak Formulations.- 1.7. Inverse Problem and Boundary Solutions.- 1.8. Classification of Approximate Methods.- References.- 2 Potential Problems.- 2.1. Introduction.- 2.2. Elements of Potential Theory.- 2.3. Indirect Formulation.- 2.4. Direct Formulation.- 2.5. Boundary Element Method.- 2.6. Two-Dimensional Problems.- 2.6.1. Source Formulation.- 2.7. Poisson Equation.- 2.8. Subregions.- 2.9. Orthotropy and Anisotropy.- 2.10. Infinite Regions.- 2.11. Special Fundamental Solutions.- 2.12. Three-Dimensional Problems.- 2.13. Axisymmetric Problems.- 2.14. Axisymmetric Problems with Arbitrary Boundary Conditions.- 2.15. Nonlinear Materials and Boundary Conditions.- 2.15.1. Nonlinear Boundary Conditions.- References.- 3 Interpolation Functions.- 3.1. Introduction.- 3.2. Linear Elements for Two-Dimensional Problems.- 3.3. Quadratic and Higher-Order Elements.- 3.4. Boundary Elements for Three-Dimensional Problems.- 3.4.1. Quadrilateral Elements.- 3.4.2. Higher-Order Quadrilateral Elements.- 3.4.3. Lagrangian Quadrilateral Elements.- 3.4.4. Triangular Elements.- 3.4.5. Higher-Order Triangular Elements.- 3.5. Three-Dimensional Cell Elements.- 3.5.1. Tetrahedron.- 3.5.2. Cube.- 3.6. Discontinuous Boundary Elements.- 3.7. Order of Interpolation Functions.- References.- 4 Diffusion Problems.- 4.1. Introduction.- 4.2. Laplace Transforms.- 4.3. Coupled Boundary Element - Finite Difference Methods.- 4.4. Time-Dependent Fundamental Solutions.- 4.5. Two-Dimensional Problems.- 4.5.1. Constant Time Interpolation.- 4.5.2. Linear Time Interpolation.- 4.5.3. Quadratic Time Interpolation.- 4.5.4. Space Integration.- 4.6. Time-Marching Schemes.- 4.7. Three-Dimensional Problems.- 4.8. Axisymmetric Problems.- 4.9. Nonlinear Diffusion.- References.- 5 Elastostatics.- 5.1. Introduction to the Theory of Elasticity.- 5.1.1. Initial Stresses or Initial Strains.- 5.2. Fundamental Integral Statement.- 5.2.1. Somigliana Identity.- 5.3. Fundamental Solutions.- 5.4. Stresses at Internal Points.- 5.5. Boundary Integral Equation.- 5.6. Infinite and Semi-Infinite Regions.- 5.7. Numerical Implementation.- 5.8. Boundary Elements.- 5.9. System of Equations.- 5.10. Stresses and Displacements Inside the Body.- 5.11. Stresses on the Boundary.- 5.12. Surface Traction Discontinuities.- 5.13. Two-Dimensional Elasticity.- 5.14. Body Forces.- 5.14.1. Gravitational Loads.- 5.14.2. Centrifugal Load.- 5.14.3. Thermal Loading.- 5.15. Axisymmetric Problems.- 5.15.1. Extension to Nonaxisymmetric Boundary Values.- 5.16. Anisotropy.- References.- 6 Boundary Integral Formulation for Inelastic Problems.- 6.1. Introduction.- 6.2. Inelastic Behavior of Materials.- 6.3. Governing Equations.- 6.4. Boundary Integral Formulation.- 6.5. Internal Stresses.- 6.6. Alternative Boundary Element Formulations.- 6.6.1. Initial Strain.- 6.6.2. Initial Stress.- 6.6.3. Fictitious Tractions and Body Forces.- 6.7. Half-Plane Formulations.- 6.8. Spatial Discretization.- 6.9. Internal Cells.- 6.10. Axisymmetric Case.- References.- 7 Elastoplasticity.- 7.1. Introduction.- 7.2. Some Simple Elastoplastic Relations.- 7.3. Initial Strain: Numerical Solution Technique.- 7.3.1. Examples - Initial Strain Formulation.- 7.4. General Elastoplastic Stress-Strain Relations.- 7.5. Initial Stress: Outline of Solution Techniques.- 7.5.1. Examples: Kelvin Implementation.- 7.5.2. Examples: Half-Plane Implementation.- 7.6. Comparison with Finite Elements.- References.- 8 Other Nonlinear Material Problems.- 8.1. Introduction.- 8.2. Rate-Dependent Constitutive Equations.- 8.3. Solution Technique: Viscoplasticity.- 8.4. Examples: Time-Dependent Problems.- 8.5. No-Tension Materials.- References.- 9 Plate Bending.- 9.1. Introduction.- 9.2. Governing Equations.- 9.3. Integral Equations.- 9.3.1. Other Fundamental Solutions.- 9.4. Applications.- References.- 10 Wave Propagation Problems.- 10.1. Introduction.- 10.2. Three-Dimensional Water Wave Propagation Problems.- 10.3. Vertical Axisymmetric Bodies.- 10.4. Horizontal Cylinders of Arbitrary Section.- 10.5. Vertical Cylinders of Arbitrary Section.- 10.6. Transient Scalar Wave Equation.- 10.7. Three-Dimensional Problems: The Retarded Potential.- 10.8. Two-Dimensional Problems.- References.- 11 Vibrations.- 11.1. Introduction.- 11.2. Governing Equations.- 11.3. Time-Dependent Integral Formulation.- 11.4. Laplace Transform Formulation.- 11.5. Steady-State Elastodynamics.- 11.6. Free Vibrations.- References.- 12 Further Applications in Fluid Mechanics.- 12.1. Introduction.- 12.2. Transient Groundwater Flow.- 12.3. Moving Interface Problems.- 12.4. Axisymmetric Bodies in Cross Flow.- 12.5. Slow Viscous Flow (Stokes Flow).- 12.6. General Viscous Flow.- 12.6.1. Steady Problems.- 12.6.2. Transient Problems.- References.- 13 Coupling of Boundary Elements with Other Methods.- 13.1. Introduction.- 13.2. Coupling of Finite Element and Boundary Element Solutions.- 13.2.1. The Energy Approach.- 13.3. Alternative Approach.- 13.4. Internal Fluid Problems.- 13.4.1. Free-Surface Boundary Condition.- 13.4.2. Extension to Compressible Fluid.- 13.5. Approximate Boundary Elements.- 13.6. Approximate Finite Elements.- References.- 14 Computer Program for Two-Dimensional Elastostatics.- 14.1. Introduction.- 14.2. Main Program and Data Structure.- 14.3. Subroutine INPUT.- 14.4. Subroutine MATRX.- 14.5. Subroutine FUNC.- 14.6. Subroutine SLNPD.- 14.7. Subroutine OUTPT.- 14.8. Subroutine FENC.- 14.9. Examples.- 14.9.1. Square Plate.- 14.9.2. Cylindrical Cavity Problem.- References.- Appendix A Numerical Integration Formulas.- A.1. Introduction.- A.2. Standard Gaussian Quadrature.- A.2.1. One-Dimensional Quadrature.- A.2.2. Two- and Three-Dimensional Quadrature for Rectangles and Rectangular Hexahedra.- A.2.3. Triangular Domain.- A.3. Computation of Singular Integrals.- A.3.1. One-Dimensional Logarithmic Gaussian Quadrature Formulas.- A.3.3. Numerical Evaluation of Cauchy Principal Values.- References.- Appendix B Semi-Infinite Fundamental Solutions.- B.1. Half-Space.- B.2. Half-Plane.- References.- Appendix C Some Particular Expressions for Two-Dimensional Inelastic Problems.

1,424 citations

Book
15 Oct 1972
TL;DR: In this article, the authors present the theoretical foundations in sound radiation and scattering, and in plate and shell vibrations required for the solution of coupled acoustics-structural vibrations problems.
Abstract: "Sound, Structures, and Their Interaction" covers theoretical acoustics, structural vibrations, and the interaction of elastic structures with an ambient acoustic medium. It is intended both as a text for graduate-level courses and as a reference book for researchers in various areas of underwater acoustics. It is self-contained and presents the theoretical foundations in sound radiation and scattering and in plate and shell vibrations required for the solution of coupled acoustics-structural vibrations problems.First published in 1972, "Sound, Structures, and Their Interaction" has been extensively revised to incorporate new results, with a particular emphasis on novel asymptotic solutions that provide physical insight as well as a check on numerical solutions. The book differs from other texts not only in its thorough treatment of the interaction of elastic structures with the ambient medium but also in its derivation of short-wavelength asymptotic solutions of sound diffraction (creeping waves) and of high-frequency vibrations of shells.This new edition also covers specialized problems, such as sound propagation in bubble swarms and in liquid-filled elastic waveguides and the effect of stiffeners on the response of submerged plates. The chapters dealing with acoustics proper provide powerful analytical techniques that the reader can apply to specific radiation and scattering situations.Miguel C. Junger is President and Principal Scientist, Cambridge Acoustical Associates, Inc. David Feit is a Research Scientist in the Ship Acoustics Department of the David W. Taylor Naval Ship Research and Development Center, Bethesda, Maryland.

923 citations

Journal ArticleDOI
TL;DR: In this article, the authors propose to decompose the problem into a fluid and a structural part through an additive decomposition of the space of kinematically admissible test functions, which can be discretised in time by implicit, stable, energy conserving time integration schemes and solved by simple, iterative uncoupled algorithms.

598 citations

Journal ArticleDOI
TL;DR: In this paper, a new computational capability is described for calculating the sound-pressure field radiated or scattered by a harmonically excited, submerged, arbitrary, three-dimensional elastic structure.
Abstract: A new computational capability is described for calculating the sound‐pressure field radiated or scattered by a harmonically excited, submerged, arbitrary, three‐dimensional elastic structure. This approach, called nashua, couples a nastranfinite element model of the structure with a boundary element model of the surrounding fluid. The surface fluid pressures and normal velocities are first calculated by coupling the finite element model of the structure with a discretized form of the Helmholtz surfaceintegral equation for the exterior fluid. After generation of the fluid matrices, most of the required matrix operations are performed using the general matrix manipulation package available in nastran. Farfield radiated pressures are then calculated from the surface solution using the Helmholtz exterior integral equation. The overall capability is very general, highly automated, and requires no independent specification of the fluid mesh. An efficient, new, out‐of‐core block equation solver was written so that very large problems could be solved. The use of nastran as the structural analyzer permits a variety of graphical displays of results, including computer animation of the dynamic response. The overall approach is illustrated and validated using known analytic solutions for submerged spherical shells subjected to both incident pressure and uniform and nonuniform applied mechanical loads.

222 citations