The Pressure and Temperature Effects on Brittle to Ductile Transition in PS and PMMA

Abstract

Tensile experiments in polystyrene (PS) and poly(methyl methacrylate) (PMMA) conducted at constant strain rate over a wide range of pressure and temperature have shown that a brittle to ductile transition is induced in these amorphous polymers by the superposition of hydrostatic pressure as well as by the raise of the experimental temperature. A detailed stress-strain analysis permits explanation of the mechanism for the brittle to ductile transition in terms of interaction between two competing processes of plastic yielding -- crazing and shear banding phenomena. The crazing and shear banding processes respond quite differently to changes of pressure or temperature. The evidence that the brittle to ductile transition pressure becomes lower with increasing temperature refutes a previously suggested concept that the transition relates primarily to mechanical relaxation phenomena.

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Document Details

Document Type
Technical Report
Publication Date
Sep 05, 1975
Accession Number
ADA015237

Entities

People

  • E. Baer
  • K. Matsushige
  • S. V. Radcliffe

Organizations

  • Case Western Reserve University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alkenes
  • Barometric Pressure
  • High Pressure
  • Hydrostatic Pressure
  • Materials
  • Materials Science
  • Military Research
  • Plastic Deformation
  • Polymers
  • Pressure Measurement
  • Shear Bands
  • Strain Rate
  • Stress Strain Relations
  • Stresses
  • Transition Temperature
  • Transitions

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Polymer Science and Technology
  • Theoretical Analysis.