The viscoelastic and viscoplastic behavior of low-density polyethylene

Aleksey D. Drozdov, Qiang Yuan

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Three series of tensile tests with constant cross-head speeds (ranging from 5 to 200 mm/min), tensile relaxation tests (at strains from 0.03 to 0.09) and tensile creep tests (at stresses from 2.0 to 6.0 MPa) are performed on low-density polyethylene at room temperature. Constitutive equations are derived for the time-dependent response of semicrystalline polymers at isothermal deformation with small strains. A polymer is treated as an equivalent heterogeneous network of chains bridged by temporary junctions (entanglements, physical cross-links and lamellar blocks). The network is thought of as an ensemble of meso-regions linked with each other. The viscoelastic behavior of a polymer is modelled as thermally-induced rearrangement of strands (separation of active strands from temporary junctions and merging of dangling strands with the network). The viscoplastic response reflects mutual displacement of meso-domains driven by macro-strains. Stress-strain relations for uniaxial deformation are developed by using the laws of thermodynamics. The governing equations involve five material constants that are found by fitting the observations. Fair agreement is demonstrated between the experimental data and the results of numerical simulation. It is shown that observations in conventional creep tests reflect not only the viscoelastic, but also the viscoplastic behavior of an ensemble of meso-regions.

Original languageEnglish
Pages (from-to)2321-2342
Number of pages22
JournalInternational Journal of Solids and Structures
Volume40
Issue number10
DOIs
StatePublished - 1 Jan 2003
Externally publishedYes

Keywords

  • Low-density polyethylene
  • Semicrystalline polymers
  • Viscoelasticity
  • Viscoplasticity

Fingerprint

Dive into the research topics of 'The viscoelastic and viscoplastic behavior of low-density polyethylene'. Together they form a unique fingerprint.

Cite this