Speaker
Description
Fiber reinforced plastics (FRPs) have previously been considered demisable because of their organic nature and the fact that they would be able to burn at ground conditions. However, entry flight simulations revealed that this assumption was overly optimistic. Instead of quickly burning away, fiber reinforced composites typically behave similar to the materials used in ablative thermal protection systems. This means that the composites go through a thermal decomposition with production of char residue, which keeps the fibers attached and the part solid. Thereby, the thermal decomposition of the matrix absorbs huge amounts of heat and creates a protective cold gas layer on the surface of the part. This results in FRPs being a problematic material category in respect of the ground-risk and the design of demisable hardware.
The majority of the plasma wind tunnel tests conducted on FRPs in the past showed a high demise resistance, but a small number of tests demonstrated a more favorable behavior that resulted in an increased demise rate. The COMP2DEM project aims at identifying the parameters that determine the behavior and deriving design rules that allow formulation of composites with increased demisability.
The project has now come to an end. In this talk, we present the project and its results and discuss the different types of demise behavior observed in the simulations and what led to that behavior. We conclude with a set of preliminary best-practices and an outlook to suggested future developments.
