Accession Number : ADA260940


Title :   Development of an Inertially-Loaded Test Fixture for In-flight Evaluation of an Acoustic Emission Monitoring System


Descriptive Note : Final rept.


Corporate Author : NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLOGY DIRECTORATE


Personal Author(s) : Kulowitch, P J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260940.pdf


Report Date : Jul 1991


Pagination or Media Count : 48


Abstract : An Inertially-loaded test fixture was designed for use with an in- flight acoustic emission monitoring system. The fixture provides a controlled method of simulating structural cracking during flight. It will be used to determine if acoustic emission monitoring is a viable method for monitoring crack growth in aircraft structures which are difficult to access and inspect. The inertially-loaded fixture was designed to use mechanical levers combined with the accelerations of the aircraft to produce the force necessary to cause crack propagation in a test specimen. The fixture minimizes the volume of the device by using a cantilevered specimen along with a loading lever arm which crosses back over the specimen to generate an equivalent lever length of 90 inches within the 21 x 4.5 x 5 inch fixture. The fixture and encasement weigh 23 pounds. The cantilever grip can accommodate specimens of various materials, widths, and thicknesses with minimal alterations to the fixture.


Descriptors :   *AIRCRAFT , *ACOUSTIC DETECTION , *FATIGUE(MECHANICS) , *CRACK PROPAGATION , *ACOUSTIC EMISSIONS , TEST AND EVALUATION , MONITORING , LOADS(FORCES) , CANTILEVER BEAMS , TEST FIXTURES , WIDTH , ACOUSTICS , FLIGHT , CRACKS , CRACKING(FRACTURING) , ACCELERATION , EMISSION


Subject Categories : Aircraft
      Acoustic Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE