Implementation of a molecular interphase model within a multiscale framework for polymer matrix composites

Joel P. Johnston, Bonsung Koo, Nithya Subramanian, Aditi Chattopadhyay

Research output: Contribution to conferencePaper

Abstract

This paper presents the development of a novel methodology for modeling the interphase between carbon fiber and polymer matrix using atomistic scale simulations. The model is integrated within a multiscale framework for the analysis of polymer matrix composites. The interphase region that exists between carbon fiber and polymer matrix plays an important role in damage initiation and it is critical for modeling damage propagation across length scales. The developed interphase model in this work consists of multiple pseudo-damaged graphene layers, and is capable of capturing the physical entanglement between the polymer matrix and the carbon fiber through the use of molecular dynamics simulations. The pseudo-damage model simulates voids in the graphene layer by removing carbon atoms, while multiple pseudo-damaged graphene layers represent the amorphous structure of the carbon fiber surface. In order to accurately model the chemical structure of the polymer, a numerical curing process is employed that captures the stochastic interactions between resin and hardener molecules for crosslinking (carbon-nitrogen covalent bond generation). The molecular dynamics model also enables extraction of the material properties of the interphase at the nanoscale which is then integrated within a high fidelity generalized method of cells micromechanics theory. A modified Bodner-Partom viscoplastic theory is applied to the polymer matrix subcells. Additionally, progressive damage and failure theories are used at different scales in the modeling framework to accurately capture scale-dependent failure of the composite material. Comparative studies are performed by applying different interphase properties that are obtained from the literature to the interphase subcells. The results indicate that the responses for each type of interphase model are similar, but the transverse tensile strength, obtained using the MD simulated interphase properties, is approximately 7% lower than the other interphase types and also has a maximum difference of 10% in failure strain.

Original languageEnglish (US)
StatePublished - Jan 1 2015
Event20th International Conference on Composite Materials, ICCM 2015 - Copenhagen, Denmark
Duration: Jul 19 2015Jul 24 2015

Other

Other20th International Conference on Composite Materials, ICCM 2015
CountryDenmark
CityCopenhagen
Period7/19/157/24/15

Keywords

  • And the U.S. Air Force Office of Scientific Research
  • Interphase
  • Molecular dynamics
  • Multiscale model
  • Polymer matrix composite
  • Stochastic
  • Technical monitor: Dr. Asher Rubinstein
  • Technical monitor: Dr. David Stargel
  • This research is supported in parts by the U.S. Army Research Office

ASJC Scopus subject areas

  • Engineering(all)
  • Ceramics and Composites

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  • Cite this

    Johnston, J. P., Koo, B., Subramanian, N., & Chattopadhyay, A. (2015). Implementation of a molecular interphase model within a multiscale framework for polymer matrix composites. Paper presented at 20th International Conference on Composite Materials, ICCM 2015, Copenhagen, Denmark.