Date of Award

2025

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Mechanical Engineering-Engineering Mechanics (PhD)

Administrative Home Department

Department of Mechanical and Aerospace Engineering

Advisor 1

Gregory M. Odegard

Committee Member 1

Trisha Sain

Committee Member 2

Ravindra Pandey

Committee Member 3

Gowtham S

Abstract

Polymer matrix composites and carbon-carbon composites play critical roles in the aerospace, automotive, and construction industries. Different matrix materials and processing conditions can lead to a large variety of composite materials and composite properties. Integrated computational materials engineering has been used to tailor PMC matrix materials and processing conditions to specific properties and manufacturing techniques. The integrated computational materials engineering process modeling framework uses molecular dynamics at the nanometer length scale to characterize the evolving thermo-mechanical properties of the polymer as it cures. Then finite element analysis is used at the micrometer length scale to adjust cure cycles to tailor the composite material properties.

The goal of this work is to extend the integrated computational materials engineering based processing modeling from polymer matrix composites to carbon-carbon composites. This requires the ability to accurately model the polymerization and pyrosis process in molecular dynamics. As such a molecular dynamic workflow was generated to quickly and accurately model the polymerization and pyrolysis process, that allows for the prediction of the evolution of thermo-mechanical properties. The initial polymerization and pyrolysis process was modeled on a furan resin material using the ReaxFF force field.

Advancements of molecular force field parameterization was generated to allow simple and easy parameterization of different molecular system in a tool called LUNAR. LUNAR supports many force fields, allows for conversion between all supported force fields, allows for easy modeling of chemical reactions in the LAMMPS software, and provides simple analysis of molecular dynamics outputs. Finally, a reformulation of ClassII force fields was performed to allow for bond dissociation to occur. The reformulated functional form was derived to be able to allow for automatic parameterization of the parameters from the existing parameters. The new functional form of the force field is termed ClassII-xe.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Available for download on Saturday, October 04, 2025

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