DYNAMIC PLASTIC DEFORMATION OF METAL UNDER COMBINED STRESS STATES.

Abstract

The objectives of the investigation was to obtain experimental information which would contribute to the understanding of the mechanisms involved in the dynamic plastic behavior of metals and which would aid in the development of constitutive equations applicable for plastic deformation at high rates of strain. The experimental program involved two essentially different, yet complementary, types of tests. In the first type of test a short tubular specimen was subjected to dynamic loading in combined tension and torsion for a period of time that was very long relative to the time required for stress wave propagation in the specimen. The objective of such a test was to obtain a dynamic stress-strain curve for straining along an essentially radial path in strain space. In the second type of test a long tubular specimen, initially pre-stressed in torsion, was subjected to a longitudinal impact. Because each of the plastic strain components (longitudinal and torsional) depends on both the normal stress and the shear stress, coupling between the longitudinal motion and the torsional motion occurs. As a result, combined longitudinal and torsional plastic waves are propagated. Study of this type of wave propagation provides insight into the form of the constitutive equations for dynamic plastic deformation under combined stress. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1970
Accession Number
AD0706894

Entities

People

  • J. Duffey
  • R. J. Clifton

Organizations

  • Brown University

Tags

DTIC Thesaurus Topics

  • Constitutive Equations
  • Couplings
  • Equations
  • Plastic Deformation
  • Shear Stresses
  • Stress Strain Relations
  • Stress Waves
  • Stresses
  • Wave Propagation
  • Waves

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Structural Dynamics.

Technology Areas

  • Space