A STRUCTURAL HEALTH MONITORING SYSTEM FOR IMPACT AND DAMAGE DETECTION IN SPACE STRUCTURES

Abstract

Space-based assets, such as satellites, are highly vulnerable to damage at all stages of their lifecycles. In particular, on-orbit events, such as impacts with space debris, micrometeoroids, and other vehicles, present major operational and logistical concerns. A Structural Health Monitoring (SHM) system deployed on satellite structures holds the promise of in-situ detection of impact events and monitoring of associated damage, thereby becoming a critical component of any On-orbit Servicing, Assembly, and Manufacturing (OSAM) strategy. The authors explored the feasibility of such an SHM system by instrumenting aluminum plates and a satellite panel with an integrated network of distributed piezoelectric sensors and then subjecting them to a series of impact tests with a wide range of forces. Satellite panels typically have a complex geometry due to stiffening ribs, and, consequently, variable stiffness. Therefore, signals obtained from the sensors were processed taking into consideration the geometry of the impacted areas, which allowed the location of the impact on the satellite panel to be accurately determined. The impact locations and force magnitudes estimated by the SHM system were compared with the actual values and found to have a high degree of correlation, with some avenues for additional improvement identified. In addition, the SHM system’s damage-detection capability was validated in both test structures. The results show that SHM systems can be readily applied to space structures in order to provide both impact- and damage-detection capabilities.