Structural Health Monitoring Technology for Aerospace Composite Propellant Tank

In this paper the experimental activities that were performed at Thales Alenia Space (TAS-I) System, Turin, Italy by Acellent Technologies Inc is presented. The final objective was defining a Vehicle / Vehicle Subsystem, built-in Health Management System which embeds self diagnosis and prognosis functions. Under this program a Composite Overwrapped Pressure Vessel (COPV) for space applications was monitored under pressure cycling (mechanical loading). The subscale demonstrator consisted of an aluminium metallic liner over wrapped by a CFRP layer. The metallic liner is seamless and manufactured by spin-forming. The liner material is aluminum AA6061 T6, with Yield Strength of 286 MPa, as declared by the bottle supplier (US Hydrospin); expected elongation to rupture is around 10%. The test was conducted for 3 days on a water filled COPV and at the end of three days the metal liner inside the propellant tank was cracked and caused water leakage. Acellent used a statistical data interpretation technique via feature extraction and data modeling approach to demonstrate that the system was able to generate the early alarm and also capable of localizing the damage which appeared at two hot spot locations.