DAA-Based Computational Boundaries for Ground-Shock Analysis, Volume 1: DAA Formulation and Canonical Comparisons.

Abstract

This document describes the formulation and implementation of a computational boundary for elastic solids based on doubly asymptotic approximations (DAA's). DAA's combine high-frequency (wave propagation) and low-frequency (quasi-static) approximations in a systematic manner to produce a relationship between scattered-wave tractions and displacements on the boundary; this relationship approaches exactness at high and low frequencies and provides a smooth transition between. Second-order DAA's for three-dimensional, linear-elastic infinite and semi-infinite media are developed for implementation into general purpose numerical (finite element or finite difference) programs. In addition, modal DAA's for spherical cavities are developed. Then, DAA results, both general and modal, are compared with analytical and other numerical results for problems involving infinite and semi-infinite media.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1997
Accession Number
ADA332773

Entities

People

  • Brett A. Lewis
  • Thomas L. Geers

Organizations

  • University of Colorado Boulder

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Computer Programs
  • Coordinate Systems
  • Differential Equations
  • Diffraction
  • Elastic Waves
  • Equations
  • Finite Element Analysis
  • Geometry
  • Ground Shock
  • Mathematical Analysis
  • Mechanics
  • Numerical Analysis
  • Three Dimensional
  • Time Domain
  • Transient Response Analysis
  • Two Dimensional
  • Wave Propagation

Readers

  • Calculus or Mathematical Analysis
  • Control Systems Engineering.
  • Electrical Engineering