An Ultrasonic Technique for Detection of the Onset of Fatigue Damage.

Abstract

The purpose of the research is to develop an ultrasonic techniques for the detection of the onset of fatigue damange. Particular emphasis is placed on the use of ultrasonic attenuation measurements as a continuous monitor of fatigue damage during cyclic testing of metal specimens. Efforts to date have indicated that the history of attenuation during fatigue of the specimen provide an index as to the onset of failure. Ultrasonic attenuation measurements made simultaneously with fatigue tests on aluminum bars give an early warning of eminent fracture. Such a warning occurs much earlier than detection of energy reflected from a crack by conventional ultrasonic techniques. This is true for specimens which were initially defect free and for those which initially had structural defects. A systematic comparison is being made between ultrasonic attenuation and other ultrasonic techniques, principally surface wave techniques and acoustic emission techniques. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1973
Accession Number
AD0760787

Entities

People

  • Robert B. Pond Sr.
  • Robert E. Green Jr.

Organizations

  • Johns Hopkins University

Tags

DTIC Thesaurus Topics

  • Acoustic Emissions
  • Aluminum
  • Attenuation
  • Detection
  • Emission
  • Fatigue Tests (Mechanics)
  • Measurement
  • Metals
  • Surface Waves
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Materials Science (Mechanical Engineering).
  • Medical Imaging.