An Application of Direct-Sequence Spread-Spectrum Ultrasonic to Global Inspection of Bridge Components
Direct-Sequence Spread-Spectrum Ultrasonic Evaluation (DSSSUE) offers solutions to unsolved inspection problems. A “better mouse-trap”, i.e., an improvement in technology that offers an alternative solution to problems that already have adequate solutions, generally does not make it in the market place for economic reasons. We cannot over-emphasize this aspect of the technology as there must be a clear perception of “new technology” and that the new technology is automatically economical, because it offer solutions were none existed before. DSSSUE incorporates a correlation receiver. The correlation peak to correlation noise floor effectively determines the “dynamic range” of the system and, therefore, its sensitivity. The sensitivity of DSSSUE is essentially limited by the cost of the technological implementation (memory and quantization levels) and processing time (length of correlation sequence). This results in a new technology that can be made extremely sensitive to changes in a test object, is operable over a broad range of frequencies, and is adaptable to a large number of inspection scenarios, including bridge components.
KeywordsFatigue Attenuation Sine Sulfite
Unable to display preview. Download preview PDF.
- 1.Spread Spectrum Ultrasonic Evaluation final report. Spread Spectrum Ultrasonic NDT, CNDE and University Extension, Iowa State University, Ames, Iowa, June 30, 1994.Google Scholar
- 2.J.K. Kayani, S.F. Russell, K.F. Hoech, M.A.K. Afzal, and S.J. Wormley, in Review of Progress in QNDE, Vol. 14A, eds D.O. Thompson and D.E. Chimenti, (Plenum, New York, 1995).Google Scholar
- 3.M.A.K. Afzal, S.F. Russell, J.K. Kayani, Sangmin Bae, K.F. Hoech, and S.J. Wormley, in Review of Progress in QNDE, Vol. 14A, eds D.O. Thompson and D.E. Chimenti, (Plenum, New York, 1995).Google Scholar