Modeling of craze evolution equation based on chemical kinetics and craze evolution simulation for crystalline polymer using homogenization method of molecular chain plasticity

Hideyuki Hara, Kazuyuki Shizawa

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The fracture of ductile polymers occurs on a boundary between the molecular chain-oriented region and the non-oriented region after the neck propagation. This behavior is caused by the concentration of craze that is a microscopic damage typically observed in polymers. In this paper, the craze evolution behavior is decomposed into the nucleation and the growth of craze. A craze evolution equation is newly developed on the basis of chemical kinetics introducing strain rate and stain dependencies into an activation energy. Furthermore, in order to reflect the damage effect to the constitutive equation of molecular chain plasticity model, damaged and pseudo-undamaged configurations are defined. Then, using a multiscale material model homogenizing mixed structure of the glassy phase expressed by the molecular chain plasticity model and the crystalline phase represented by the usual crystal plasticity model in an unit cell, a FE simulation coupling with the craze evolution equation is carried out for a crystalline polymer subjected to the uniaxial load. It is attempted to computationally reproduce characteristic behaviors of craze evolution, i.e., the propagation of craze concentration region with the neck propagation in macroscopic specimen, the cessation of increase of craze in the molecular chain-oriented region and the craze nucleation before the macroscopic yielding.

Original languageEnglish
Pages (from-to)1604-1619
Number of pages16
JournalNihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
Volume79
Issue number807
Publication statusPublished - 2013

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Keywords

  • Chemical KINETICS
  • Craze
  • Crystal plasticity
  • Crystalline polymer
  • Damage mechanics
  • Finite element method
  • High polymer materials
  • Inelasticity
  • Molecular chain plasticity
  • Multiscale analysis

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Science(all)

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