Accession Number : ADA318666

Title :   Thermal Wave Imaging of Hidden Corrosion in Aircraft Components.

Descriptive Note : Final rept. 1 Jul 93-30 Jun 96,

Corporate Author : WAYNE STATE UNIV DETROIT MI INST FOR MANUFACTURING RESEARCH

Personal Author(s) : Thomas, R. L. ; Favro, L. D. ; Kuo, P. K.

PDF Url : ADA318666

Report Date : 22 NOV 1996

Pagination or Media Count : 22

Abstract : A program of basic research was carried out, whose objective was to make the promising qualitative thermal wave imaging NDI technique a truly quantitative tool which can have a major impact on the rapid, wide-area inspection of Air Force aircraft for hidden corrosion in aircraft components. During the program a theoretical framework was developed, based on three-dimensional scattering of thermal waves from planar subsurface defects, and the model was used to predict the images of circular sub-surface defects of various radii, located at various depths from the surface of the metal. Experimental measurements on such model structures confirmed the validity of the theory and determined the parameters for applying the technique to the imaging of hidden corrosion in aircraft components. Preliminary testing of the technique was carried out on an aircraft, with corrosion being successfully imaged. Outstanding technical issues include the effects of corrosion products and other realistic thermal - boundaries which are encountered in actual aircraft structures, and the development of quantitative corrosion loss estimation algorithms.

Descriptors :   *CORROSION, *NONDESTRUCTIVE TESTING, *THERMAL IMAGES, IMAGE PROCESSING, MILITARY AIRCRAFT, AIR FORCE RESEARCH, AIRCRAFT MAINTENANCE, CORROSION INHIBITION, DEFECTS(MATERIALS), INFRARED IMAGES, THERMAL DIFFUSION, CORROSION RESISTANCE, FUSELAGES, AIRCRAFT EQUIPMENT, COMPUTER AIDED DIAGNOSIS, SKIN(STRUCTURAL), THERMAL DEGRADATION, INFRARED OPTICAL SYSTEMS, HEAT TRANSMISSION, INFRARED PHOTOGRAPHY.

Subject Categories : Properties of Metals and Alloys
      Infrared Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE