<p dir="ltr">This paper explores the use of acoustic-based structural health monitoring (SHM) to detect damage and failure in aluminum pipelines used to carry resources to lunar habitats. Acoustic-based SHM on Earth is a well studied field of research. Various studies validate the effectiveness of acoustic-based SHM to detect, locate, and characterize damage in pipelines. To the authors’ knowledge, little or no research has been attempted to simulate lunar pipelines, or to apply SHM techniques to lunar pipelines.&nbsp; In this paper, AE waveforms were collected and analyzed for pipes that were subjected to simulated lunar conditions. Experiments mimicking lunar regolith abrasion, internal galvanic corrosion, and irradiation were conducted on aluminum pipes. A wind tunnel extension was built to house an aluminum pipe sample and regolith simulant. The wind tunnel abraded the aluminum pipe with the regolith simulant and appropriate waveforms were collected. An impressed current technique experiment accelerated the internal corrosion of an aluminum pipe that held a static salt solution. Radiation samples were placed inside the aluminum pipe and waveform acquisition was attempted. Lunar structures are constantly subjected to abrasion and irradiation. As such, it is important to detect and manage the noise resulting from these lunar hazards. Water-carrying pipelines must be monitored as pitting due to corrosion will eventually cause a leak. Regolith abrasion may delaminate thin films used to protect against atomic oxygen corrosion. It is not known whether or not radiation causes acoustic emission or structural defects. Irradiation noise would lower the efficiency of an acoustic-based SHM technique. As a result, corrosion events will be overlooked. The waveform data was clustered based on hit-driven and time-driven properties. Changes in the wave propagation throughout the tests were observed as clusters in the AE data. The weak radiation samples did not induce AE from the aluminum pipe. Unique waveform characteristics were compiled for the abrasion and corrosion tests. Continually monitoring the AE of common corrosion and damage events using AE sensors will improve the ability to predict and prevent catastrophic pipeline failure. The waveform clusters can serve as a benchmark to filter out unnecessary noise and to more accurately detect corrosion and abrasion waveforms in real-time. A library of waveform data can thus be built and used to analyze structures in unknown environments. The ultimate goal of this study is to add redundancy to other anti-corrosion techniques for spatial structures. Safe extraterrestrial habitations will better house humans, and will bring humanity one step closer to inhabiting space.&nbsp;</p>

Acoustic Emission-Based Structural Health Monitoring for Future Lunar Pipelines

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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