Investigation of EMAT Base System for the Detection of Bolt Hole Type Cracks. Part 1. Detection of Cracks in the Inaccessible Lower Half of Wing Lap Joints Using EMATS

Abstract

The detection of saw slots in an aircraft wing lap joint is demonstrated with EMATS (Electromagnetic acoustic transducers) utilizing 250 KHz horizontal shear acoustic waves reflected from the fastener area. A real-time Fourier transform signal processor was developed and used to gather experimental data and generate plots of power vs. frequency as well as the complex transform. A simple ultrasonics model is described which is capable of explaining many of the features of the experimental data.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1980
Accession Number
ADA094349

Entities

People

  • C. V. Vasile
  • R. B. Thompson
  • R. H. Houston

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Signals
  • Acoustic Waves
  • Air Force
  • Data Acquisition
  • Detection
  • Diffraction
  • Dispersion Relations
  • Experimental Data
  • Geometry
  • Pattern Recognition
  • Power Spectra
  • Scattering
  • Signal Processing
  • Transducers
  • Ultrasounds
  • Wave Propagation
  • Waveforms

Fields of Study

  • Physics

Readers

  • Radar Systems Engineering.
  • Structural Health Monitoring of Composite Structures.