Table of Content

Open Access

ARTICLE

Size-Dependent Behavior of Macromolecular solids II: Higher-Order Viscoelastic Theory and Experiments

D. C. C. Lam1, L-H Keung1, P. Tong2
Department of Mechanical Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People’s Republic of China, Tel: (852)2358-8661, Fax: (852)2358-1543, Email: david.lam@ust.hk
Bioengineering Department, University of California at San Diego, La Jolla, CA 92093-0412

Computer Modeling in Engineering & Sciences 2010, 66(1), 73-100. https://doi.org/10.3970/cmes.2010.066.073

Abstract

Additional molecular rotations in long chained macromolecules lead to additional size dependence. In this investigation, we developed the higher order viscoelasticity framework and conducted experiments to determine the higher order material length scale parameters needed to describe the higher order viscoelastic behavior in the new framework. In the first part of the investigation of high order deformation behavior of macromolecular solids, the higher-order viscoelasticity theories for Maxwell and Kelvin-Voigt materials, and models of higher-order viscoelastic beam deflection creep are developed in this study. We conducted creep bending experiments with epoxy beams to show that the creep deflection behavior followed the conventional Kelvin-Voigt viscoelastic behavior when the beams are thick and that higher-order size dependences are present in both the time-independent elastic and time-dependent creep deflection when the beams are thin. The higher-order viscoelastic creep bending model with a higher-order material length scale parameter, l2, was shown to be in good agreement with the data. Furthermore, l2 is chain-based, instead of mechanism-based. Since each macromolecular solid has only a single set of chains, only a single l2 is needed to characterize its higher order behavior in the newly developed higher order viscoelasticity framework. The new single l2 higher order viscoelastic theory can be used to describe viscoelastic nanomechanical behaviors in nanostructured macromolecular solids.

Keywords

polymer, creep, viscoelastic, size effect, strain gradient

Cite This Article

C., D., Keung, L., Tong, P. (2010). Size-Dependent Behavior of Macromolecular solids II: Higher-Order Viscoelastic Theory and Experiments. CMES-Computer Modeling in Engineering & Sciences, 66(1), 73–100.



This work is licensed under a Creative Commons Attribution 4.0 International License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • 831

    View

  • 645

    Download

  • 0

    Like

Share Link

WeChat scan