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Constitutive Modeling of Viscoelastic Unloading of Glassy Polymers

  • Yves Remond
Conference paper
Part of the Solid Mechanics and Its Applications book series (SMIA, volume 114)

Abstract

The simulation by traditional uni-dimensional rheological models of viscoelastic unloading to zero stress after tensile testing of polyethylene and its composites is poor. The models significantly underestimate recovery rates, even with small amounts of strain. The use of a finite number of relaxation times does not sufficiently increase recovery rates during unloading when models are generated from the responses of materials under load. Similar results and observations are obtained using rate jumps in loading and unloading. 3D models developed using local state methods require that an additional recovery potential be used. A simple 2D model is proposed here which takes into account the differences in local behaviour seen during loading and unloading, thus justifying the existence of this potential. The similar situation that exists for composites means that the phenomenon must not be confused with material damage.

Key words

Viscoelasticity unloading constitutive equations polyethylene polypropylene 

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Copyright information

© Springer Science+Business Media Dordrecht 2004

Authors and Affiliations

  • Yves Remond
    • 1
  1. 1.Institut de mécanique des fluides et des solides - UMR 7507 ULP/CNRSUniversité Louis PasteurStrasbourgFrance

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