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Durham University

Department of Engineering

Staff Profile

Publication details for Professor Jun Jie Wu

Buckley, C.P. & Wu, J.J. (2003), Anisotropic plastic deformation of glassy polymers with process-induced molecular orientation, 19th Annual Meeting of the Polymer Processing Society. Melbourne, Australia.
  • Publication type: Conference Paper

Author(s) from Durham


The constitutive modelling of glassy thermoplastics is extended to the case of anisotropy arising from processinduced
molecular orientation. The basis of the work is the Glass-Rubber model framework, known to capture
well the constitutive response of isotropic amorphous polymers on either side of the glass transition. The key
feature of the new model is that the thermally-activated diffusion event is recognised as being intrinsically
anisotropic. Melt-process history establishes an orientation distribution for the relaxing units. In modelling
subsequent deformation below Tg the stress is integrated over this distribution. The model naturally exhibits
many aspects of behaviour seen experimentally: increase of yield stress, apparent reduction of activation volume
and increasing strain-stiffening with increasing orientation.


Presented at the 19th Annual Meeting of the Polymer Processing Society, Melbourne, 7-10 July 2003.