  Epoxy resins are used extensively in composite materials for a wide range of
engineering applications, including structural components of aircraft and
spacecraft. The processing of fiber-reinforced epoxy composite structures
requires carefully selected heating and cooling cycles to fully cure the resin
and form strong crosslinked networks. To fully optimize the processing
parameters for effective epoxy monomer crosslinking and final product
integrity, the evolution of mechanical properties of epoxies during processing
must be comprehensively understood. Because the full experimental
characterization of these properties as a function of the degree of cure is
difficult and time-consuming, efficient computational predictive tools are
needed. The objective of this research is to develop an experimentally
validated Molecular Dynamics (MD) modeling method, which incorporates a
reactive force field, to accurately predict the thermo-mechanical properties of
an epoxy resin as a function of the degree of cure. Experimental rheometric and
mechanical testing are used to validate an MD model which is subsequently used
to predict mass density, shrinkage, elastic properties, and yield strength as a
function of the degree of cure. The results indicate that each of the physical
and mechanical properties evolve uniquely during the crosslinking process.
These results are important for future processing modeling efforts.
