Physically-based interpretation of abnormal stress relaxation response in glassy polymers

Lin, Ji; Zhu, Panpan; Tian, Chuanshuai; Zhou, Haofei

doi:10.1016/j.eml.2022.101667

Cited by 12 publications

(1 citation statement)

References 51 publications

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“…[ 7–9 ] Other viscous characteristics shown by glassy polymers include stress relaxation under constant strain and creep under constant stress. [ 10–14 ] Nowadays, glassy polymers have been widely deployed as structural materials due to their high modulus and toughness. However, understanding their mechanical behavior is quite difficult at present and has been a long‐standing issue to be resolved in the research area of polymer mechanics and physics.…”

Section: Introductionmentioning

confidence: 99%

Experimental and constitutive analyses of the stress relaxation behavior of glassy polymers

Liu

Wang

Zhang

et al. 2023

Polymer Engineering & Sci

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The physical mechanism underlying the mechanical behavior of glassy polymers has been studied over decades but remains a long‐standing issue. A consensus view achieved is that the yield, flow, and stress relaxation behaviors are due to structural relaxation in the polymer mainly caused by chain conformation transitions. This is the key physical idea behind the many existing elastic–plastic constitutive models for glassy polymers. In this paper, such a constitutive model was employed for predicting and analyzing the stress relaxation of a glassy polymer. It is found that the model works well in predicting the pre‐yield stress relaxation but significantly underestimates the post‐yield stress relaxation. As considering the chain conformation transition alone leads to a dilemma for the model to concurrently represent the yield/flow and stress relaxation behaviors, the model was extended to incorporate an additional structural relaxation mechanism assumed to originate from the dissociation of weak linkages in the chain network. The extended model succeeds in concurrently representing the yield/flow, and stress relaxation behaviors in the whole deformation region, of which the reasons were analyzed. The knowledge revealed in this paper is instructive and may shed new light on understanding the structural relaxation and mechanical behavior of glassy polymers.

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Section: Introductionmentioning

confidence: 99%