Skip to main content
Baseline UT measurements for armor inspection
Center for Nondestructive Evaluation Conference Papers, Posters and Presentations
  • Frank J. Margetan, Iowa State University
  • Nathaniel L. Richter, Iowa State University
  • Daniel J. Barnard, Iowa State University
  • David K. Hsu, Iowa State University
  • Timothy A. Gray, Iowa State University
  • Lisa H. Brasche, Iowa State University
  • R. Bruce Thompson, Iowa State University
Document Type
Conference Proceeding
Review of Progress in Quantitative Nondestructive Evaluation
Publication Date
(41.4803791, -71.5225598)
Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch∕catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through‐transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces.

Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

This article appeared in AIP Conference Proceedings 1211 (2010): 1217–1224 and may be found at

Copyright Owner
American Institute of Physics
Citation Information
Frank J. Margetan, Nathaniel L. Richter, Daniel J. Barnard, David K. Hsu, et al.. "Baseline UT measurements for armor inspection" Kingston, RI(2009)
Available at: