Air-coupled ultrasonic tomography of solids: 1 Fundamental development

Kerry S. Hall, John S. Popovics

Research output: Contribution to journalArticlepeer-review


Ultrasonic tomography is a powerful tool for identifying defects within an object or structure. But practical application of ultrasonic tomography to solids is often limited by time consuming transducer coupling. Air-coupled ultrasonicmeasurements may eliminate the coupling problem and allow for more rapid data collection and tomographic image construction. This research aims to integrate recent developments in air-coupled ultrasonic measurements with current tomography reconstruction routines to improve testing capability. The goal is to identify low velocity inclusions (air-filled voids and notches) within solids using constructed velocity images. Finite element analysis is used to simulate the experiment in order to determine efficient data collection schemes. Comparable air-coupled ultrasonic signals are then collected through homogeneous and isotropic solid (PVC polymer) samples. Volumetric (void) and planar (notch) inclusions within the samples are identified in the constructed velocity tomograms for a variety of transducer configurations. Although there is some distortion of the inclusions, the experimentally obtained tomograms accurately indicate their size and location. Reconstruction error values, defined as misidentification ofthe inclusion size and position, were in the range of 1.5-1.7%. Part 2 of this paper set will describe the application of this imaging technique to concrete that contains inclusions.

Original languageEnglish (US)
Pages (from-to)17-29
Number of pages13
JournalSmart Structures and Systems
Issue number1
StatePublished - Jan 2016


  • Air-coupled
  • Non-contact
  • Non-destructive testing
  • Tomography
  • Ultrasound

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Computer Science Applications
  • Electrical and Electronic Engineering

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