The Panel Interface Measurement Experiment on the CMC Forebody of the ATHEAt Hypersonic Vehicle

Abstract

The deformation of reusable ceramic matrix composite (CMC) thermal protection systems (TPS) during hypersonic flight depends on complex aero-thermostructural coupling. Understanding the deformation at CMC TPS panel interfaces is important for preventing hot gas ingress and ensuring vehicle survivability. The paper presents the design and development of an in-flight deformation measurement experiment for monitoring the carbon fiber reinforced silicon carbide (C/C-SiC) aeroshell panel gaps of the ATHEAt hypersonic flight vehicle. The experiment uses a laser triangulation sensor to capture a high-resolution two-dimensional profile across the interface of neighboring panels. The experimental architecture is driven by the numerically predicted hypersonic thermal environment and vehicle vibrational loads. Finite element simulations indicate that coupled thermomechanical loads cause a panel lateral expansion, constricting the interface gap by roughly 0.8 mm during flight. These results provide a baseline for the experiment integration into the vehicle and enable future flight data correlation.