| Popis: |
Glassy carbon (GC) materials demonstrate excellent thermal stability and mechanical response with low mass densities, which makes them excellent candidates for use in ablatives and carbon-carbon composites (C/C composites) used in aerospace and hypersonic vehicle structures. Although GC materials have been in development and use for decades, molecular simulation protocols need to be developed to accelerate the optimization of processing cycles and to drive the development of the next generation of C/C composites. The objective of this research is to establish reactive molecular dynamics (MD) simulation protocols to accurately predict the evolution of the molecular structure and properties of furan resin during polymerization and pyrolysis processes. The polymerization simulation protocols have been validated via comparison of the predicted density and Young’s modulus of furan resin with experimental values. The MD pyrolysis simulations protocols are validated by comparison of calculated density, Young’s modulus, carbon content, sp2 carbon content, the in-plane crystallite size (La), out-of-plane crystallite stacking height (Lc), and inter-planar crystallite spacing (d002) with experimental results from the literature for furan resin derived GC. Simulation parameters, such as temperature and pressure, are optimized within relatively short simulation times (2000 ps), and the predicted structures and mechanical properties are shown to agree with experimental measurements. The modeling methodology established in this work can provide guidance for the development of next-generation C/C composite precursor chemistries for thermal protection systems and other high-temperature applications. |
