Patents Examined by Hal P. Wachsmann
  • High speed thin plate fatigue crack monitor
    Patent number: 5493511
    Abstract: A device and method are provided which non-destructively detect crack length and crack geometry in thin metallic plates. A non-contacting vibration apparatus produces resonant vibrations without introducing extraneous noise. Resulting resonant vibration shifts in cracked plates are correlated to known crack length in plates with similar resonant vibration shifts. In addition, acoustic emissions of cracks at resonance frequencies are correlated to acoustic emissions from known crack geometries.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: February 20, 1996
    Assignee: Administrator, National Aeronautics and Space Administration
    Inventors: Buzz A. Wincheski, Joseph S. Heyman, Min Namkung, James P. Fulton