INTERACTION OF PLANE STRESS WAVES WITH A SPHERICAL CAVITY IN ELASTIC AND VISCOELASTIC MEDIA.

Abstract

Methods are given for the determination of stresses in the vicinity of a spherical cavity in an unbounded elastic or viscoelastic medium as a result of a step wave engulfing the cavity. Incident longitudinal and shear waves are considered. Two approaches are used for the solution. In the first, the solution is expressed in terms of generating functions which are determined from the boundary conditions at the cavity wall. For the elastic case, this method is analogous to the d'Alembert solution in one-dimensional wave propagation in which the general solution of the wave equation is used. The elastic case requires the solution of coupled systems of ordinary differential equations of initial value type. In the viscoelastic case, these are replaced by systems of integro-differential equations of Volterra type. Numerical methods are used for the solution of the equations. The second method proceeds by finding the Laplace transforms of the desired stresses and performing the inversions numerically. Viscoelastic materials represented by the Maxwell model and the standard linear model have been used for the computations presented. On the basis of these computations, conclusions are drawn concerning the effect of viscoelasticity of rock on the dynamic stress concentrations around a cavity in the rock making use of properties of rock determined for low stress levels. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1966
Accession Number
AD0631501

Entities

People

  • A. R. Robinson
  • D. E. Allen

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Computations
  • Differential Equations
  • Equations
  • Secondary Waves
  • Stress Concentration
  • Stress Waves
  • Stresses
  • Wave Equations
  • Wave Propagation
  • Waves

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Mechanical Engineering/Mechanics of Materials.