Effects of Defect Size and Number Density on the Transmission and Reflection of Guided Elastic Waves

Abstract

We explore the scattering of guided elastic waves in plastic cylinders by wavelength-sized defects. A random field of defects is introduced into the cylinder in a localized region, a photoacoustic source generates elastic waves on one side of the damaged region, and then two ultrasound transducers measure the amplitude of the waves transmitted and reflected by the damaged region. We found that for defects approximately 3 in diameter that the transmission amplitude decays exponentially in the volumetric number density of defects. Furthermore, we discovered that the for a constant defect density, in the Mie regime, there is not statistically significant transmission amplitude variation between different defect sizes. Additionally, in the Mie regime, the reflected wave due to backscatter is too small to be detected with our equipment.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Apr 22, 2016
Accession Number
AD1033752

Entities

People

  • Ryan J. Gelly

Organizations

  • MIT Lincoln Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplitude
  • Bone Fractures
  • Ceramic Materials
  • Cross Correlation
  • Damage Detection
  • Detection
  • Elastic Waves
  • Inverse Scattering
  • Laser Spots
  • Lasers
  • Materials
  • Mie Scattering
  • Phase Shift
  • Pulsed Lasers
  • Rayleigh Scattering
  • Scattering
  • Waves

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.