Ultrasonic F-Scan Inspection of Composite Materials.
Final rept. 9 May 83-9 May 84,
DREXEL UNIV PHILADELPHIA PA ULTRASONICS RESEARCH LAB
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Composites are being used in high-strength, low-weight applications such as the aircraft industry. Difficulties arise in the nondestructive testing and evaluation of these materials because of their fibrous nature. Therefore, a study was connected to evaluate, improve, and optimize ultrasonic techniques for the detection of programmed delaminations and other defects in graphiteepoxy composite laminates. A pulse echo testing mode was used and C-scan results were analyzed. To overcome the limits of traditional C-scan, F-scanning Feature scanning was also used. This method examines many characteristic features of the ultrasonic waveform such as amplitude, frequency shifts, etc. Feature scanning has the potential to precisely locate and characterize the defects. Micrographic analyses were made to determine defective and good areas for correlation with the results obtain in the F-scan process. The results of the C-scan, F-scan, and photomicrographs showed an excellent correlation. Specific conclusions are drawn to assist future operators in conducting consistent and reliable C-scans. Situations where F-scanning might be suitable are also reviewed. Author
- Laminates and Composite Materials
- Acoustic Detection and Detectors