NDE and Stress Monitoring on Composite Overwrapped Pressure Vessels

Damage caused by composite overwrapped pressure vessels (COPVs) failure can be catastrophic. Thus, monitoring condition and stress in the composite overwrap, including the fiber layers most prone to failure is needed during both preflight qualification and spaceflight. We will develop practical Non-destructive Evaluation (NDE) capability for use during spaceflight and surface mounted magnetic stress gages (MSGs) for preflight qualifications/testing and in-flight monitoring. NDE will address damage produced by impacts from micro-meteoroid orbital debris (MMOD). In addition, we will investigate the need to inspect through multi-layer insulation layer (MLI).The goal is to demonstrate feasibility of (i) volumetric stress monitoring using light weight, surface mounted MSGs, and (ii) practical, portable and easy to interpret NDE for use by crews during spaceflight, with limited training and minimal logistics support. Dual purpose electronics will be adapted to the constraints of spaceflight for NDE and MSG data acquisition and the feasibility of developing extremely light weight and small form factor electronics suitable for space flight will be investigated. This proposal is founded on successful implementations of JENTEK MWM-Array technology forthe Space Shuttle leading edge RCC and recent feasibility demonstrations for MSG volumetric stress monitoring on COPV sections. The MWM-Arrays and MSGs use linear drive winding constructs to selectively induce eddy currents in different fiber layers to assess damage and monitor stresses.