Experimental Mechanics

, Volume 44, Issue 4, pp 407–415 | Cite as

Wave propagation in multi-wire strands by wavelet-based laser ultrasound

  • P. Rizzo
  • F. Lanza di Scalea


Methods based on guided ultrasonic waves are gaining increasing attention for the non-destructive inspection and condition monitoring of multi-wire strands used in civil structures such as prestressing tendons and cable stays. In this paper we examine the wave propagation problem in seven-wire strands at the level of the individual wires comprising the strand. Through a broad-band, laser ultrasonic setup and a time—frequency wavelet transform processing, longitudinal and flexural waves are characterized in terms of dispersive velocity and frequency-dependent attenuation. These vibrating frequencies propagating with minimal losses are identified as they are suitable for long-range inspection of the strands. In addition, the wave transmission spectra are found to be sensitive to the load level, suggesting the potential for continuous load monitoring in the field.

Key Words

Non-destructive evaluation laser ultrasound wavelet transform guided waves 


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Copyright information

© Society for Experimental Mechanics 2004

Authors and Affiliations

  • P. Rizzo
    • 1
  • F. Lanza di Scalea
    • 1
  1. 1.NDE & Structural Health Monitoring Laboratory, Department of Structural EngineeringUniversity of California San DiegoLa JollaUSA

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