Advanced DAA Methods for Shock Response Analysis

Abstract

Doubly asymptotic approximations (DAA's) are approximate contact- surface relations for the dynamic interaction between a body and an adjacent medium. In this report, first- and second-order DAA's are formulated for an internal acoustic domain, and a first-order DAA is formulated and implemented in boundary-element form for a semi-infinite elastic domain. The new DAA's constitute extensions of DAA's previously formulated and implemented for external acoustic and infinite elastic domains. The accuracy of the internal DAA's is evaluated by comparing DAA and exact solutions for a canonical problem, namely, the excitation of a fluid-filled spherical shell submerged in an infinite acoustic medium by a plane step-wave; in this evaluation, the second- order DAA exhibits satisfactory accuracy. A preliminary evaluation of the first- order DAA for a semi-infinite elastic medium is conducted by comparing boundary- element DAA results with results in the literature for a suddenly pressurized spherical cavity; marginal accuracy is observed. Underwater Shock, Ground Shock, Acoustics, Medium-Structure Interaction. Elasto-Dynamics,

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1992
Accession Number
ADA252696

Entities

People

  • Brett A. Lewis
  • Peizhen Zhang
  • Thomas L. Geers

Organizations

  • University of Colorado Boulder

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Waves
  • Acoustics
  • Boundaries
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Eigenvalues
  • Engineering
  • Finite Element Analysis
  • Fourier Series
  • Geometry
  • Ground Shock
  • Integral Equations
  • Modal Analysis
  • Three Dimensional
  • Wave Equations

Fields of Study

  • Mathematics

Readers

  • Electrical Engineering
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Structural Dynamics.