Acoustic Nondestructive Evaluation of Aircraft Paneling Using Piezoelectric Sensors.

摘要

The U.S. Army Research Laboratory has constructed a nondestructive evaluation (NDE) system for monitoring structural health in aircraft paneling. Our system relies on commercially available Piezoelectric Wafer Active Sensors (PWASs). These sensors were bonded to 0.063-in-thick aircraft-grade high- strength aluminum (alloy 2024) sheets using commercially available strain gauge adhesive, and 22 arbitrary waveform generator hook-up wire was soldered to each one to establish electrical contact. Audio and ultrasonic burst-modulated sinusoidal signals were applied to a single PWAS using an arbitrary waveform generator. The acoustic response was detected by the remaining sensors and measured using an oscilloscope. The location of defects in the aircraft paneling was determined using a multilateration algorithm based on a cross- correlation technique. In order to test the detection limits of our NDE system, holes with a variety of diameters were intentionally drilled through the aluminum panels. Our system was able to detect holes with diameter sizes that were comparable to the panel thickness.