Multiscale modeling of progressive failure in polymer nanocomposites using nanoscale informed damage mechanics

ABSTRACT

In this article, a novel technique to model damage and damage evolution in polymer nanocomposites (PNCs) using the internal state variable approach is proposed. The multiscale aspects of the nanocomposite are captured by embedding local inhomogeneities and the localized nanoparticle (nanographene) and polymer atom interactions at the interface into a continuum scale damage model. This approach assumes that the damage evolution is primarily due to changes in nonbonded interactions at the nanoscale, hence the moniker nanoscale-informed damage mechanics (NIDM) model. The unknown coefficients in the NIDM model are obtained by a linear regression fit of the polymer and the PNC stress-strain behavior using molecular dynamics simulation. It is envisioned that the resulting nonlinear constitutive model can be readily incorporated into a hierarchical multiscale finite element model and used by the aerospace industry for structural scale applications to model progressive failure.

KEYWORDS:

• nanoscale
• damage mechanics
• nonbonded interaction
• interface
• Van der Waals

Funding

This research was funded through a NASA Aero-Sciences NRA grant, Grant No. NNX11AI32A, with Dr. Brett Bednarcyk at NASA GRC as technical project monitor.