Here is the abstract you requested from the IMAPS_2011 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Studies of Mesoscale Models Parameterized by Molecular Models for Interface Failure in Epoxy Molding Compounds|
|Keywords: Multiscale modeling, molecular modeling, mesoscale modeling|
|Deeper understanding of material failure must include consideration of contributions from the molecular and atomistic scales from which a more complete root cause picture may be constructed. The current study, supported by an international consortium effort (NanoInterface) , reports efforts to bridge the gap between molecular models and macroscale models by use of a mesoscale discrete particle method. The system used for the current study was an epoxy molding compound (being studied within the NanoInterface consortium) and concentrated on models of the epoxy-copper oxide adhesive interface and the epoxy cohesive interface. To derive the mesoscale models, unit cell molecular models representing the atomistic construction of the epoxy and copper oxide were converted to unit cell particle or “bead” mesoscale models based upon repeat units. This transition from the molecular to the mesoscale unit cell represented >100 fold reduction in the number of model particles, which enabled the construction of a much larger mesoscale model using supercell replicates, representing a final polymer molecular weight of 8M (compared to the starting 20K molecular weight of the molecular model). Bead interaction parameters for energy optimization and dynamics of the mesoscale model were then derived from molecular dynamics of the repeat units. By applying deformations in the unit cell, reasonable moduli were calculated and void generation was found. Efforts to represent the later part of the stress-strain curve (representing the energy release phase of the stress-strain curve) will also be reported. Future work includes further scaling the interface to determine if roughness may be included in the mesoscale model. The Accelrys software Discover for the atomistic scales, and Mesocite for the mesoscale were used in this study.  This project was partially funded under FP7, Project NanoInterface (NMP-2008-214371)|
|Nancy Iwamoto, Research Manager
Honeywell International, Inc.