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

摘要

This document describes the formulation and implementation of a computationalboundary 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.