About this Abstract |
Meeting |
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
Symposium
|
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
Presentation Title |
Mechanisms of Atomic Oxygen Erosion of Fiber-Reinforced Composites |
Author(s) |
Fuyue Li, Chaitanya S. Deo |
On-Site Speaker (Planned) |
Chaitanya S. Deo |
Abstract Scope |
In Low Earth Orbit (LEO) environments, the dominant species of atomic oxygen (AO) chemically erodes polymers, leading to mass loss and a rough surface. Kapton based fiber-reinforced composites are commonly used as thermal blankets for spacecraft due to the matrix’ thermal stability and wear resistance. Experiments show that N2 enhances the erosion rate of oxidized hydrocarbon due to higher collisional energy. In-flight experiments show a linearly increasing trend with the N2 fraction for the sub-LEO environment.
Molecular dynamics simulations conducted with the ReaxFF force field are employed to elucidate the erosion of polymer based fiber composite behavior under AO bombardment. Such simulations are usually conducted at a very high flux rate, which leads to increasing temperature in the atomistic simulations which is not physically observed in laboratory experiments or in-flight conditions.
In this project, we introduce a new atomistic technique to mitigate the simulation induced-temperature increase for Kapton. We find that with this approach the mass loss yield is much closer to the experiment. The new approach agrees well with the experiment for the initialization stage, but not for the steady-state mass loss stage. The limitations will be further discussed by conducting scattering dynamics. Further, the sub-LEO environment is implemented to investigate the effects of varying fractions of AO/N2 for the initialization stage. Mass loss and chemical changes are quantified to better understand the damage. The new method can be extended to other materials under atomic oxygen erosion. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |