Three-dimensional Crack Depth Profile Assessment using Near-Field Surface Acoustic Wave Signal Response (Postprint)

Abstract

A method for determining the three-dimensional depth profile of a surface-breaking crack-like feature is presented based on near-field surface acoustic wave signal responses. Three-dimensional finite element models were used to study the forward problem, where the characteristic near-field scattering of a surface acoustic wave incident on a surface breaking crack was investigated. Experimental validation of the modeling predictions was accomplished using a wedge transducer for surface wave generation and a scanning laser vibrometry system for surface wave detection. The characteristic near-field amplitude response in reflection and in transmission was measured and modeled for flat-bottom, angled, and curved bottom localized notch features, where a simple linear inversion method was developed, which provided an effective means for characterizing and mapping the three-dimensional depth profile of surface-breaking crack-like features with depths in the micron to millimeter range.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2012
Accession Number
ADA557043

Entities

People

  • James L. Blackshire

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Waves
  • Air Force
  • Air Force Research Laboratories
  • Amplitude
  • Elastic Waves
  • Frequency
  • Geometry
  • Materials
  • Military Research
  • Near Field
  • Rayleigh Waves
  • Scattering
  • Surface Acoustic Wave Devices
  • Surface Acoustic Waves
  • Three Dimensional
  • Transducers
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Structural Health Monitoring of Composite Structures.

Technology Areas

  • Directed Energy