MICROWAVE TECHNIQUES AS APPLIED TO NONDESTRUCTIVE TESTING OF NONMETALLIC MATERIALS.
Abstract
Microwave techniques utilizing basic transmission, reflection and scattering phenomena were developed for a nondestructive testing program at two frequencies, 9.6 GHz and 35 GHz. The test specimens used include epon 828 and 815 resin samples, retread rubber tire, fiberglass tubes and pitted metal plates. The results obtained indicate that the techniques are useful for the measurement of thickness and for the detection of flaws, lack of bond, and degree of cure for geometrically smooth, homogenious samples. A 15 cm thick epoxy resin sample was measured to an accuracy of plus or minus 0.1 mm at 9.6 GHz. The present laboratory setup however, is not capable of detecting small defects in complex, nonhomogeneous samples. Resolution of such defects is limited by the irregularities of the sample surface, the difficulty of focusing the antenna beam and the abrupt or random change in material composition. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1967
- Accession Number
- AD0652268
Entities
People
- Don Latshaw
- Joseph T. Lehman
- Theresa M. Lavelle