Interaction of Lamb Waves with Fatigue Cracks in Aluminum

Abstract

Elastic waves can travel across relatively large distances in thin metallic plates, and can be affected by discontinuities such as cracks. This paper presents an investigation of the interaction of Lamb waves with both open and closed low-cycle fatigue cracks in aluminum plates using a three-dimensional laser Doppler vibrometer (3D-LDV). The 3D-LDV provides measurements of both in- and out-of-plane velocity components over a uniform grid of up to ~27,000 points with approximately 0.7 mm spacing in the x- and y-directions. Images created from the 3D-LDV measurements clearly show the interaction of the elastic wave energy with the cracks. Comparisons between in- and out-of-plane components provide insight into whether and how the propagation behaviors of symmetric and antisymmetric Lamb wave modes differ upon encountering fatigue cracks.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2011
Accession Number
ADA585023

Entities

People

  • C. Allen
  • C. T. Owens
  • Eric D. Swenson

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Biomedical
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Aluminum
  • Cracks
  • Detection
  • Detectors
  • Energy
  • Frequency
  • Frequency Shift
  • Governments
  • Laser Doppler Vibrometers
  • Measurement
  • Monitoring
  • Simulations
  • Structural Health Monitoring
  • Wave Power
  • Wave Propagation
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Materials Science and Engineering.

Technology Areas

  • Directed Energy
  • Space