Spoolable composite tubes were acquired from Hydril (courtesy of Thomas J. Walsh.)

Ultrasonic inspection station has been assembled. Four-point bending test setup and a setup for controlled impact of pipe were manufactured. A real-time data analysis algorithm was developed to invert ultrasonic time domain signal to the properties of the individual composite layers of the filament wound Spoolable tube. A modification of Habibi-Ashrafi and Mendel suboptimal maximum-likelihood parameter estimator was developed. It consists of two filters connected in series: a matched filter to treat noise; and a transversal equalizing filter to correct for wavelet overlapping effects. An optimization of the transversal equalizing filter has been performed to increase numerical stability of detection. For medium and high noise levels, section methods remained stable, although a number of false boundaries were found. Automatic defect classification algorithm was developed. The algorithm automatically recognizes, identifies, and classifies defects of different types using the pulse-echo technique, dramatically reducing inspection time. The classification process extracts several features from the time and frequency domain responses of the ultrasonic echo signals and attribute position in feature space to the probability of different practical defects (for instance voids, cracks, delaminations, etc.) appearing in composite tubes during manufacturing and in service. Non-contact acoustic emission monitoring during tubular spooling is under development.

The final detailed results are not available from MMS.

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Last Updated: 09/22/2008, 07:05 AM