AN ULTRASONIC NONDESTRUCTIVE TEST PROCEDURE FOR THE EARLY DETECTION OF FATIGUE DAMAGE AND THE PREDICTION OF REMAINING LIFE

The goal of nondestructive testing may be simply expressed as the detection and complete specification (size, shape, orientation, etc.) of flaws. This is seldom possible, however. The most dangerous flaw is one that is crack-like or that serves as a crack initiation site. A procedure to detect and estimate fatigue damage occurring at such a site is reported. A computer based data acquisition system is used to analyze data from 2024-T4 A1 fatigue specimens containing a through hole. Specimens are fatigue loaded to produce a spectrum of damage levels and interrogated using a simple contact 10 MHz shear wave system. Features selected from the signal amplitude time, spectrum, and cepstrum signatures are used in a computer learning network to make an early detection of fatigue damage and a quantitative prediction of remaining life. A scanning microscope is used to examine the damage at the limit of detection. Fatigue damage was sensed with 92% success after 10% of specimen life. Estimates of damage were made within plus or minus 20 of the actual fatigue life percentage for 76% of the data.

  • Corporate Authors:

    Drexel University

    32nd and Chestnut Streets
    Philadelphia, PA  United States  19104
  • Authors:
    • Carson, J M
    • Rose, J L
  • Publication Date: 1978-8

Media Info

  • Features: References;
  • Pagination: 90 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00187996
  • Record Type: Publication
  • Source Agency: Drexel University
  • Contract Numbers: N00014-77-C-0607
  • Files: TRIS
  • Created Date: Feb 3 1979 12:00AM