Windowing of Full Wavefield Data in Multiple Domains to Characterize Angle-Beam Shear Wave Scattering (Postprint)

Abstract

Angle-beam ultrasonic inspection methods are frequently based on shear waves since they are readily generated using conventional longitudinal transducers and a wedge. Full wavefield imaging can be employed to measure such waves on the surface of a plate-like specimen after they have scattered from a feature or defect of interest, and multiple shear wave arrivals, or skips, are readily visible due to beam spread [1]. Because of the complexity of the total wavefield, which also includes Rayleigh and longitudinal waves, it is challenging to experimentally quantify scattering from the primary skip of interest. Considered here is a methodology to isolate shear wave scattering from a through-hole caused by a specific shear wave skip that is incident upon the hole. First, the residual wavefield is obtained by performing wavefield baseline subtraction before and after the introduction of a scatterer [2]. Next, a 3-D Fourier transform is performed to convert the residual signals in the time and space domain (t-x-y) to the frequency-wavenumber domain (omega-kx-ky).

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2017
Accession Number
AD1036549

Entities

People

  • Jennifer E. Michaels
  • Yu Weng

Organizations

  • Georgia Tech

Tags

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Air Force Research Laboratories
  • Frequency
  • Frequency Shift
  • Governments
  • Military Research
  • Residuals
  • Scattering
  • Secondary Waves
  • Signal Processing
  • Three Dimensional
  • Ultrasonic Inspection
  • United States
  • Waves

Fields of Study

  • Physics

Readers

  • Approximation Theory.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Structural Health Monitoring of Composite Structures.

Technology Areas

  • Space