The Ductile Brittle Transition of Low Density Polyethylene,

Abstract

An extensive test program to determine the brittleness of low density, blown polyethylene film was undertaken as a result of failures of high altitude balloons constructed of this film. In this work, ductility and brittleness are defined by the ultimate elongations in uniaxial, constant strain rate tests. At each strain rate used it is shown that a critical temperature could be defined where the ultimate elongation changes significantly. It is suggested that this temperature be considered the cold brittleness temperature. Large deformations at break, referred to here as ductile behavior, are associated with yield and plastic flow. This phenomenon requires extensive freedom of motion of molecular chain segments, which can be determined from the dissipation (tan delta) CURVES. The tan delta curves demonstrate that the ductile behavior can be correlated with the strength of the beta transition and its domination of the relaxation spectrum. (Author, modified-PL)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1972
Accession Number
AD0757885

Entities

People

  • Dan Weissmann

Organizations

  • Stevens Institute of Technology

Tags

DTIC Thesaurus Topics

  • Altitude
  • Brittleness
  • Critical Temperature
  • Dielectric Polymers
  • Ductile Brittle Transition
  • Ductility
  • Elongation
  • High Altitude
  • Low Density
  • Plastic Flow
  • Strain Rate
  • Transitions

Readers

  • Approximation Theory.
  • Reinforced Composite Materials
  • Structural Health Monitoring of Composite Structures.