DYNAMIC TESTING AND WAVE PROPAGATION IN A STRAIN RATE SENSITIVE MATERIAL,

Abstract

Short specimens of Armco iron were tested at room temperature under compressive, axial loads at strains up to 0.6 percent and strain rates up to 1000 in/in-sec. During loading, the axial stress was measured with a thin, piezoceramic disk inserted between the specimen and loading bar. The surface strain was measured with conventional epoxy-backed, foil strain gages, and the strain rate deduced by differentiating the strain vs. time record. The stress, strain, and strain rate data were plotted and were found to be approximated by a particular constitutive functional. The constitutive equation was then used along with the governing equations of motion and continuity in finding a numerical solution to the problem of a one-dimensional plastic wave propagating in a rate sensitive bar caused by an initial axial stress sigma (0,t). The solutions at two locations for both stress and strain were found to compare favorably with the stress and strain measured in a long bar impact test. (Author)

Document Details

Document Type
Technical Report
Publication Date
Dec 16, 1968
Accession Number
AD0680247

Entities

People

  • Hal Watson Jr

Organizations

  • Southern Methodist University

Tags

DTIC Thesaurus Topics

  • Axial Loads
  • Constitutive Equations
  • Continuity
  • Equations
  • Equations Of Motion
  • Gages
  • Impact Tests
  • Materials
  • Mathematics
  • Statistics
  • Strain Gages
  • Strain Rate
  • Wave Propagation

Readers

  • Calculus or Mathematical Analysis
  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.