NASA Glenn Research and NASA White Sands Test Facility have developed software supporting an automated pressure vessel structural health monitoring (SHM) system based on acoustic emissions (AE). The software, referred to as the Acoustic Emission Analysis Applet (AEAA), provides analysts with a tool that can interrogate data collected on Digital Wave Corp. and Physical Acoustics Corp. software using a wide spectrum of powerful filters and charts. This software can be made to work with any data once the data format is known. The applet will compute basic AE statistics, and statistics as a function of time and pressure (see figure). AEAA provides value added beyond the analysis provided by the respective vendors’ analysis software. The software can handle data sets of unlimited size.

The Front Panel is divided into the following main sections: (1) Run-time menu; File, Options, Help; (2) AE & Fast Fourier Transform graphs; (3) AE analysis settings; and (4) AE statistics.
A wide variety of government and commercial applications could benefit from this technology, notably requalification and usage tests for compressed-gas and hydrogen-fueled vehicles. Future enhancements will add features similar to a “check engine” light on a vehicle. Once installed, the system will ultimately be used to alert International Space Station crew members to critical structural instabilities, but will have little impact to missions otherwise. Diagnostic information could then be transmitted to experienced technicians on the ground in a timely manner to determine whether pressure vessels have been impacted, are structurally unsound, or can be safely used to complete the mission.

This work was done by Don J. Roth and Charles T. Nichols of Glenn Research Center, and was sponsored by the NASA Non-destructive Evaluation Working Group.

Inquiries concerning rights for the commercial use of this invention should be addressed to

NASA Glenn Research Center
Innovative Partnerships Office
Attn: Steven Fedor
Mail Stop 4–8
21000 Brookpark Road
Cleveland
Ohio 44135.

LEW-19032-1