The Conversion of Plastic Work to Heat Around a Dynamically Propagating Crack in Metals

Abstract

Investigations of the temperature rise at a dynamically propagating crack tip using an infrared detector array are reported. Also, a measurement of the fraction of plastic work converted to heat using a split hopkinson bar apparatus in conjunction with an infrared detector array is summarized. For 4340 steel it is seen that approximately 85% of the plastic work is converted to heat leading to a temperature rise of 300 deg C at a crack tip propagating 600 m/s in steel. This results is compared to earlier studies that report a 450 deg C temperature rise at a crack tip propagating 900 m/s in steel. In a titanium alloy the temperature rise is higher than that in steel for equal plastic work rate densities. The conditions at the crack tip are shown to be adiabatic, and, as a result, this effect is due to the difference in density, heat capacity and crack tip speed. Thermal conductivity has no effect.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1991
Accession Number
ADA253801

Entities

People

  • A. J. Rosakis
  • G. Ravichandran
  • J. J. Mason

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Adiabatic Conditions
  • Bulk Materials
  • Crack Tips
  • Cracks
  • Detectors
  • Differential Equations
  • Equations
  • High Temperature
  • Infrared Detectors
  • Materials
  • Measurement
  • Partial Differential Equations
  • Shear Bands
  • Strain Rate
  • Stress Strain Relations
  • Thermal Conductivity
  • Titanium

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Mechanical Engineering/Mechanics of Materials.
  • Thermal Physics or Thermal Science.