Non-Contract Ultrasonic Diagnostic Systems

摘要

The objective of this project was to develop advanced non-contract instrumentation for nondestructive detection and characterization of critical flaws in aircraft structures as part of a timely quantitative nondestructive evaluation (QNDE) program. In the past several years, we have successfully developed several advanced ultrasonics NDE techniques that are relevant to the Air Force. This project was aimed at further development of advanced non-contact laser ultrasonic instrumentation for NDE so as to facilitate flaw detection and characterization. The sensing technique used is based on adaptive interferometry for non-contract detection of ultrasound. The generation of ultrasound is also by means of laser illumination. The advantages of using ultrasonic probe signals to interrogate the interiors of structures is well recognized. Non-contract laser ultrasonic NDE procedures, in addition: (1) provide increased speed of inspection; (2) are amenable to quantitative interpretation since they are independent of coupling efficiency (3) can be used on complex structures with curved surfaces; and (iv) can be configured (using optical fibers for instance) into very compact systems that can be used for remote inspection of hard-to-reach areas such as the interiors of fuel tanks inside wing-boxes. The technical findings are outlined in this report. The project findings offer great promise for the realization of rapid multiplexed two-mixing interferometric receivers for laser ultrasonic detection of flaws in aircraft structures.