Development of an inertially-loaded test fixture for in-flight evaluation of an acoustic emission monitoring system : Navel Air Development Center, Warminster, Pennsylvania (United States), AD-A260 940/2/GAR, 47 pp. (Jul. 1991)

Abstract

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.