Finite element implementation of a macromolecular viscoplastic polymer model Academic Article uri icon


  • This paper presents a time-integration method for a viscoplastic physics-based polymer model at finite strains. The macromolecular character of the model resides in (i) the viscoplastic law based on a double-kink molecular mechanism, and (ii) a full chain network model inspired by rubber elasticity to describe the large-strain orientation hardening. A back stress enters the constitutive model formulation. Essential aspects of a three-dimensional finite-element implementation are outlined, the main novelty being in the back stress formulation. The computational efficiency and accuracy of the algorithm are examined in a series of parameter studies. In addition, because a co-rotational formulation of the constitutive equations is employed using the Jaumann rate in the hypoelastic equation and the back stress evolution equation a detailed analysis of stress oscillations is carried out up to very large strains in simple shear. Subsequently, three-dimensional FE analyses of compression with friction and instability propagation in tension are used as a means to demonstrate the robustness of the implementation and the potential occurrence of stress oscillations and shear bands in large-strain analyses. 2013 John Wiley & Sons, Ltd.

published proceedings

  • International Journal for Numerical Methods in Engineering

altmetric score

  • 0.5

author list (cited authors)

  • Kweon, S., & Benzerga, A. A.

citation count

  • 14

complete list of authors

  • Kweon, S||Benzerga, AA

publication date

  • June 2013